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General control line discussion => Open Forum => Topic started by: Dennis Adamisin on December 22, 2021, 10:29:00 AM
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If you follow the Stunt Hangar Chats (see “At the Bench”) hosted by Charles Carter on Mondays & Fridays, you have probably heard the ongoing discussions on how some of us have been proceeding with Spectra lines. I will be switching everything over to Spectra, and wanted to share what I have learned, as well as reach out to others with who can share their experiences.
First, for background, here are the rated strengths of SS Cable we currently use. Thank You to Brett Buck for posting this info in a thread in the Rules forum:
Nominal Diameter (in.) Const. Material Type Minimum Breaking Strength
0.0120 1 x 7 Stainless Steel 302/304 25 lbs
0.0150 1 x 7 Stainless Steel 302/304 40 lbs.
0.0180 1 x 7 Stainless Steel 302/304 55 lbs
0.021 1 x 7 Stainless Steel 302/304 80 lbs
0.0240 1 x 7 Stainless Steel 302/304 100 lbs
Spectra lines are not new to CL. For several years the AMA General rules for Control Line included a chart suggesting sizes for Spectra lines. However, Stunt event rules limited us to solid or SS Cables in specific minimum sizes. Starting January 1, 2022, Stunt rules will allow any line material & construction which passes the 10G pull test.
The Combat guys have been using 100# Power Pro line not because of its strength, but because of its diameter; their thinking was that they wanted the same line drag for Spectra versus the normally mandated .018” cable. The 1/2A Combat rules specified .012” cables, and the appropriate size Spectra line was 40# test.
The 1/2A flyers (except 1/2A Combat) have been using Spectra lines for a long time – it is the prohibitive choice, being way stronger than .008 cable, and far easier to handle. I use 15# & 20# on my 1/2A's.
Of course, many of our forum members are also avid fishermen who hopefully have practical knowledge and experience with Spectra braids that I hope they can share here.
Spectra fiber is patented by Honeywell, there is another similar fiber called Dyneema that was patented in Europe. Power Pro was the “pioneer” introducing Spectra braided line for fisherman, and over the years there are several more brands available. Braided lines are advertised as being the strongest, most durable and have “zero” stretch for maximum feel. Spectra lines do not kink or curl like SS cable can, so they should be VERY user friendly for us. Most producers have several product lines available, marketed to customers “hot buttons”; highest strength, smallest diameter, best castability – and of course price! Spectra is naturally bright white in color, but most lines come dyed in various colors.
How does it fly?:
Aside from the 1/2A’s, I first tried Suffix 832 65# x 60' on my Ringmaster a few years back. The 65# size (nominally .015”) is what is called out in the AMA General rules; but on a Ringer it is WAY overkill! Before flying we pull tested to 40# to assure that my knots were secure. In the first test flight I started off doing 5 inside loops then checked control response – no loss in feel due to lines binding together. I did a second set of 5 then a third set, each time noting absolutely no loss in feel due to lines dragging on each other. With 15 loops and no control loss I figured more loops were unnecessary. Later I used these same lines on an All-American Senior - after adding 1/2 oz inboard tip weight! To those of you who have flown an AA Senior, the idea of inboard tip weight must seem really scarry!
Later I tied a set of Suffix 832 80# for my 55 oz Pathfinder to fly at Brodak the year they allowed Spectra. Again, these lines are too big but on the PF, I took off 1/2 oz of tip weight and need to take more.
Although promising it was pointless to try Spectra on any of my PAMPA class airplanes because it could not be used in competition. Then in late fall, after the rule passed, I flew my SV-11 (72 oz) back-to-back first with the .018” seven strand cables, then Power Pro 100# line. I noticed the Spectra lines had no discernable stretch or friction. In fact, my pattern got much better because of the linearity of control I gained over cables – my round loops were finally round, I could go deeper into corners, and level flight was finally locked down. The lack of line friction may be just what we have been looking for in electric! Maybe that's why I noticed that here; might not have been as noticeable on a vibrating glow airplane? Per my usual habit, I had some built-in tip weight, so I could only remove 1/4 oz from the tip weight box, so at the field I stuck on ½ oz weight to the inboard tip for a net ¾ oz reduction in tip weight. Later, I weighed the outboard tip, then chopped it off to remove the weight I had built in plus the ½ oz stuck to the inboard side. Finished by installing 3/4 oz in the weight box to achieve the same weight measured at the tip. I think I could have pulled pull another 1/4 oz., but the weather turned for the worse and I have not been able to try it again. Next time out I will be switching to smaller/lighter Maxcuatro 80# so it is a foregone conclusion that I can remove more tip weight. In fact, I will keep pulling weight out until it goes too far then put some back.
Given that test I decided to commit to Power Pro Maxcuatro 80# (.016" dia) in place of .018” cable. Power Pro’s “Maxcuatro” brand is their tightest woven and smallest diameter line for a given rating. It is conceivable that 65# line would be adequate but seems like that would hit diminishing returns. Similar logic led me to look at 50# in place of .015" cable. Maxcuatro 50# is .012", thus yielding 20% smaller line than the cable that is also 25% stronger and lighter - not a bad trade! My main criteria will be stretch, I am not worried (too much!) about strength.
Lighter line weight and less tip weight for Spectra is a given, smaller line diameters will show up as less drag, possibly a lower RPM setting, and lower battery usage. Will less line drag affect lead-out position too? Seems like it should, but that will be easy enough to find out
Last week I tied 8 sets of lines including 4 sets for flying buddies. I tied Maxcuatro, 40# Power Pro "Super Slick 8", Suffix 832 (65# & 80#), and FINS XS 50# because it is slippery and because I liked the colors!
* The Maxcuatro 80# and Power Pro 40# were easy to handle & tie. I am awaiting a spool of green Maxcuatro 50# to go with my yellow so I can tie dual color sets (green line up!)
* The Suffix 832 (65# & 80#) were the easiest to handle. It has a real nice feel to it. These lines are larger in diameter than the Maxcuatro, about the same diameter as regular Power Pro.
* Did not like handling the FINS XS. I do not think I will be using this long term.
* I tied 3 sets with eyelets using the Palomar knot and 5 sets with Modified Surgeon's knot that the Combat guys prefer. The ones with eyelets should be easier to use with hardpoint handles.
* Crochet needle (with the hook on the end) & magnifiers HELP!
* Mine are close but NOT exact in length like the Tom Morris & Okie Air cables I have been buying.
* Instead of eyelets I think I am going to try small solid (NOT split!) rings and tie to those when not using the loop.
* I wrote the material, test, and length on each reel to keep them all straight.
A couple Links & Attachments:
* Do a SEARCH on Spectra posts SH, there are a lot of good post going way back to before when Combat adopted the lines.
* Dennis Toth found/posted a table of fishing line sizes on SH in the Combat section. I downloaded it and attached it below
* There are lots of vids on YouTube showing how to tie braid for fishing lines. If you want to keep using eyelets on the line ends, it looks like the best knots for our use are the Uni tied with the line doubled, and the Palomar which naturally is tied with a doubled line. The trouble with these knots is that they are difficult to tie at an exact location. I think our fishing buddies can help us here! Ken Culbertson posted a sketch of a tying fixture here (see post #9) that looks like it could help: https://stunthanger.com/smf/combat/spectra-lines-braided-or-solid/
* Michael Stinson has updated & expanded his YouTube video again as of 6-January on tying the Modified Surgeons knot, that the Combat guys have settled on. He also added a couple of do's & don'ts, including a really slick idea for keeping the loops in place on scissors style clips:
https://www.youtube.com/watch?v=d1l_fAPV6lA
That is just about everything I know on the subject, pending the new flying season! I seriously hope others will post their experiences and any guidelines they have on how to select and make up Spectra lines
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Good morning,
Great information Denny! There was something that was brought up during the Hangout that caught my attention. It was mentioned that the color lines tend to fade with time due to UV rays, which is no big deal. But I don't recall if anything was mentioned if this affects the integrity of lines.
My main concern is how these lines will hold up when temperatures reach the 90-100 degrees range on an asphalt or concrete surface? These surfaces can get extremely hot in the summertime. I've been in situations where my lines laid in the sun for hours. Any reasons to be concerned or will we learn the hard way through trial and error?
I know that the combat guys have been using these lines for some time now, but they fly on grass areas which don't get nearly as hot as asphalt or concrete surfaces. Should we get into the habit of replacing these lines every couple of years?
Stay safe,
Dennis
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Hello Dennis N!
From what I can tell Spectra is considered UV resistant, especially when coated. I found a reference to an accelerated UV test standard which showed Dyneema (considered by most sources to be equivalent to Spectra) to have excellent UV resistance. Spectra is used in sailcloth, which would seem to be a high-UV application.
Melting point is 300F degrees, that's even hotter than Muncie in July!
Some fosherman claim the see line fade starting on the first day, sounds like it happens faster in sailt water than in fresh, does not seem to affect anything else tho. Spectra is naturally a bright white, the dye is added on and not a factor of the forming of the Spectra material.
One of the kite line sites says Spectra is 40% stronger than Kevlar for the same weight. So probably no surprise that other uses for Spectra cloth include ballistics clothing and cut proof gloves.
Here's a chart on Dyneema UV performance:
https://assets.ctfassets.net/q6qgec8ud5tq/2F2XxEQuIxhQnlD9435Ddz/7413e91d3f25447a8f000f94f06aea7d/CIS_YA102_Ultraviolet_exposure_of_UHMWPE_fiber_from_DSM_Dyneema.pdf
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Great thread Dennis!!!
Below is a quote from back in '07 it might be worth reviewing as Phil C was answering questions.
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Open Forum / Re: Rules Proposal for Spectra(tm) Lines
« on: August 17, 2007, 12:28:58 PM »
Hey Guys,
As I was reading along, my first thought was the effects of sunlight on the spectra lines, and Pat did address that. Then I thought what about a set of lines that has been sitting on the tarmac for 5 minutes or so when your getting ready for a flight. Obviously on a 95 degree day sun gleaming those lines could get pretty hot. Is there any research on these materials possibly softening and becoming weak or even stretching in this case.
Tom
https://stunthanger.com/smf/open-forum/rules-proposal-for-spectra(tm)-lines/msg51033/#msg51033
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If the line is insulated you can use a granny knot. 30# fly line backing is used to insulate the line.
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Denny thanks for great material here. I did buy some stuff for these lines but haven’t tried them yet. I’m interested to see how they go with the .76.... one question though: I’m an incessant line cleaner, wiping the gunk off after every flight with alcohol. How is that going to work with these lines? Do they absorb moisture? How are they in wet grass? Just asking.
Carry on.
Dave
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Melting point is 300F degrees, that's even hotter than Muncie in July!
Not by much! LL~
Dennis
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This is great information and useful for the new line rules coming in January, 2022. One thing I think we need to develop is a consistent method for tying off the ends to get equal line length on the last line clip. If there is a knot that allows tightening by pulling the tag line (lose end) we could mark the line to be on the clip then tie the knot with the mark in place and tighten the tag. I have looked at all kinds of fishing line and kite line sites looking for this kind of approach and we are the only ones that need the lines that close in equal length. Anyone got a simple jig (not involving using your teeth)?
For the ends I came across what they use on cable called a "Cable Thimble" these are tear drop shaped open guides that the line rests in (like an eyelet) and you could knot at the bottom. They use this with swage ferrules (crimps to us) not sure if this could work with Spectra type line. I have seen some small thimbles for 1/16" line, even 1/32" line but not sure what would work with light thin 0.012" Spectra. The fishing guys want fast and cheap so no one tried this as far as I can find. Maybe Robert Zambelli (are CL swage/crimp SME) can try this and do some tests, would be much simpler than a knot.
Best, DennisT
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Well this is a great post Dennis. I started way last year to try and get used to the Spectra lines. Got maybe a dozen flights, but daughter took back her vehicle and this year the family took my car keys. The back has not been much help either. D>K
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Doc,
Need to either get your daughter into flying or the grand kids. Maybe a take-a-part "flat plate winger" like the Aussie "Yardstick". The Spectra lines would make teaching them easier not needing to worry about learners stepping on lines or get kinks from walking them out to fast getting bends.
Best, DennisT
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Hottest NATs runway I ever encountered was in Lake Charles in '74 Was said to be 130 degrees. All I remember is I couldn't stand still because it burned my feet. Melting temp for Spectra is 300, that seems like a pretty good margin. However, if the runway is hot maybe it would be enough to elevatethe lines, or for a long spell just reel them in.
Trib:
I have not had to clean my Spectra lines yet. Spectra does not absorb water and it is extremely resistant to acids and bases. Sure sounds like a regular alcohol wipe will do the deed. However, the dye may not be as resistant!
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If you are worried about the temp of asphalt you could build a handle stand that was weighted and hold the lines up off the surface and then only have to deal with ambient temp. This would be no more than any other material on or in your plane. After takeoff and level laps lines should be down to ambient temp. At this time you are pulling on both lines. Even on a 70oz plane and 50 pound lines you would have about a 60lbs of safety.
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Hello
I have been using Spectra for a few years now for combat (65lb for most on 52 ft and 100 for the faster stuff on 60ft) and 80lb for most bigger stunt models. Me and the whole family prefer the feel and convenience of Spectra over steel and only use steel lines where the rules require it like team race or to avoid mixed line types in combat. Has proven very durable and can be cleaned with detergent if you get fuel on them as that makes them feel sticky. Even faded to white with many years use they still pass the pull tests . They do abrade on sharp edges and will melt when wrapped around a crankshaft but endure the rigors of combat much better then 'stainless steel line and with less stretch then stainless.
Getting them in blue where possible or yellow makes it easier to see over grass and I normally mark the up line red with a red felt pen .
Regards Gerald
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I changed to fishing lines last year, and have not seen any reason to go back to steel lines!
Stay well,
Frank
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When the lines are laying on the ground, the actual contact area of the line to the pavement is very , very small. I think you would have to have something laying on the line to get any heat transfer. If there is any breeze blowing that will mitigate any temperature also, even on the ground. If it were a problem, I think some one would have experienced it by now.
MERRY CHRISTMAS!!
Dan McEntee
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Hello As for Spectra getting wet it works better then steel when wet, its more slippery when its wet not clingy like steel lines tend to do. But glow fuel oil does make them sticky (do not roll them out with oil soaked hands to avoid this) but I have cleaned them by squirting detergent on them then rinsing off then drying them. They still pass a pull tests when faded to white or almost clear too.
Regards Gerald
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While browsing on the Barton site I came across an idea for tying knots with a Fly-Fishing tool. I did a little search and found the "Knot Needle" (https://theknotkneedle.com/?msclkid=e9d3623ef56a19b044ed03f8af4d3a8a&utm_source=bing&utm_medium=cpc&utm_campaign=DSA&utm_term=theknotkneedle&utm_content=All%20Webpages)
Looking at the videos they claim it will do 20 different knots including the Uni and Palomar. It seems this could work well with Spectra lines to maybe make it easier to get them the same length. Anyone try any kind of fly-fishing tool like this?
Update: I decided to get one so will report once I get a chance to try it once it gets here in a week or so.
Best, DennisT
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Denny thanks for great material here. I did buy some stuff for these lines but haven’t tried them yet. I’m interested to see how they go with the .76.... one question though: I’m an incessant line cleaner, wiping the gunk off after every flight with alcohol. How is that going to work with these lines? Do they absorb moisture? How are they in wet grass? Just asking.
Carry on.
Dave
Good questions, Dave. No, polyethylene in any form including Spectra type lines does not absorb any significant amount of moisture. They really don't need to be cleaned, but if you want alcohol, acetone etc. will wipe off any dust they may accumulate. There are no problems at all on grass. They might, since they are more flexible than steel, not catch as easily on clumps of grass. We've locally not had any troubles.
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In the Chat last Monday, there was a discussion about tying "NEAT" loop ends in the modified surgeon's knot shown in Mike Stinson's excellent YouTube video. The discussion centered around tying small loops as a measure of "neatness" - that is misguided. While beauty is in the eye of the beholder, lets make it clear that a properly tied knot is secure whether the final loops are small or large. In my case I am trying to make the ends consistent but I typically get the final loops roughly the size of my finger.
Instead of obsessing over the size of the loops, instead concentrate on pulling all of the tags secure. Lubricate the line (spit on it!) and pull each tag until the knot is completely tight. Mike's video shows that pretty clearly. THAT is how the knots get excellent!
Best way to learn how to tie excellent knots is practice. I used the line I bought for safety thongs for teaching myself - its easy to see how the knot comes together. You could also use various sizes of rope, twine or string for practice. Next I practiced with actual Spectra line - wasted some line but learned what was important.
Mike's video did not show it, but especially when tying smaller lines, it helps to have a leather glove to protect your hand when you are pulling the tags to tighten the knot. Many of the many of the fishing line videos on YouTube recommend this too. I have to wear magnifiers to more clearly see the knot snug up. Large & light color line is easier to see...
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Thanks Denny for the great information.
Questions: What do you do with the tag ends when done pulling on them? I’m assuming that you cut the off. But how much should you let stick out pass the knot?
Dennis
Sent from my iPhone using Tapatalk Pro
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Thanks Denny for the great information.
Questions: What do you do with the tag ends when done pulling on them? I’m assuming that you cut the off. But how much should you let stick out pass the knot?
Dennis
Sent from my iPhone using Tapatalk Pro
Leave as much as you can. No matter how good you are at tying them they are going to slip some. In fact they need to to finally lock in place. It is part of the process, and you simply need to allow for it. On my Spectra sets I left an inch. Half that will probably do but, other than looking a bit unfinished, nothing is lost by having a little extra. It is super important to wet the knot before the last pull.
Ken
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Thanks Denny for the great information.
Questions: What do you do with the tag ends when done pulling on them? I’m assuming that you cut the off. But how much should you let stick out pass the knot?
Dennis
Sent from my iPhone using Tapatalk Pro
Hi Dennis,
Good question. After cinching up all the tag ends as secure as possible, I have been clipping pretty close; about 1/16" or so from the knot. However, what Ken C said about leaving a little longer tag makes sense; at least until you get more comfortable with your process.
HEY COMBAT GUYS, KITE FLYERS & FISHERMEN: how about some input here???
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One thing I was thinking about was to leave a little more tag line but slip on heat shrink tubing over the cinch end, you could leave like 1/4" and maybe 1/16" out the back of the heat shrink so you could see if it moves?
Best, DennisT
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I ordered a package of 1/64" thimbles from McMaster to try as a smooth loop end for the Spectra lines. Seems the weakest part of the connection is at the knot so having it smooth into the knot area might help. This might be overkill and fixing a problem that doesn't present a significant problem.
Best, DennisT
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I ordered a package of 1/64" thimbles from McMaster to try as a smooth loop end for the Spectra lines. Seems the weakest part of the connection is at the knot so having it smooth into the knot area might help. This might be overkill and fixing a problem that doesn't present a significant problem.
Best, DennisT
My major experience with knots on fishing line is fishing. You are absolutely correct, that the weakest point is the knot by as much as 50% if not tied so that it can gradually tighten around the eyelet. If the angle created by wrapping around the eyelet is too great the knot will pressure the line and prevent it from slipping. Others may disagree but IMHO the smaller the object you are wrapping around is (up to a point, perhaps 2-3x the diameter of the line) the more the knot can slip under pressure and not break. Slippage, although microscopic is what keeps the line from breaking. Just as an example, for our deep water rigs we cut the hooks off after each session about an inch above the knot and retied them next time out. We are not trying to lift a 100 pound fish either so I don't recommend this for our lines except to illustrate that a knot that cannot tighten any more is going to break. 99.9% of line breakage is at the knot.
Ken
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One thing I was thinking about was to leave a little more tag line but slip on heat shrink tubing over the cinch end, you could leave like 1/4" and maybe 1/16" out the back of the heat shrink so you could see if it moves?
Best, DennisT
Dennis T:
Careful if you do this, DO NOT heat shrink the tube. Too hard to control the heat, too easy to burn the line. if you want, slip the tubing on as just a sleeve, but no heat or glue.
Did you receive that knot-tying tool and have you tried it out?
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Dennis A,
The Knot Needle arrived yesterday, haven't had a chance to work with it yet. What type of knot have you been using? With all the options about this it is hard to find setups that you can trust. I was thinking of doubling over the line no matter what knot just to give more surface to spread the force over.
I found some 1/64" cable thimbles from McMaster that are teardrop shaped and will see how they work. I think because of the smooth shape it should put less stress on the knot, just need to make sure there are smooth edges. What do you think?
I want to set up a hanging weight test rig to see how the various knots will hold with different amounts of weight or maybe a simple pull scale.
Best, DennisT
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Dennis A,
The Knot Needle arrived yesterday, haven't had a chance to work with it yet. What type of knot have you been using? With all the options about this it is hard to find setups that you can trust. I was thinking of doubling over the line no matter what knot just to give more surface to spread the force over.
I found some 1/64" cable thimbles from McMaster that are teardrop shaped and will see how they work. I think because of the smooth shape it should put less stress on the knot, just need to make sure there are smooth edges. What do you think?
I want to set up a hanging weight test rig to see how the various knots will hold with different amounts of weight or maybe a simple pull scale.
Best, DennisT
Hoping the Knot Needle makes it easier to handle the line while you tie whatever knot you want to use.
CONGRATS on finding those teardrop thimbles! I can almost never find anything in M-C because they list so many things! The normal brass eyelets we used for SS cable lines have a 1/8" ID. It looks like the teardrop you found is 3/16" x 1/4" so it is a bit larger - does that matter to you?
I found the YouTube on how to tie the doubled-line Uni knot as recommended by AMA. I have tied this directly to clips on one end of the line and to round brass eyelets on the other end heck it out here:
https://www.youtube.com/watch?v=9Ls9cdyK18Y
The more I think about it the more I think my best plan is to use the Modified Surgeons knot developed by Phil Cartier, as used by the Combat guys, and as shown in the Mike Stinson video in the first post of this thread
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The reason we stayed with the modified Surgeons knot is because wrapping the line around both sides of the loop better spreads the load and increases the ultimate pull test. The first tests with the standard Surgeon's knot were no better than steel lines, about 50-55lb.
Revising the know to lock both sides of the loop made it good up to 75lbs or so, per line.
The AMA rules require the knot to be tied by first doubling it over. This wasn't done just to make it harder. I don't see it as much use in ordinary flying, but the extra strength probably did wonders for the Insurance side of the business.
Don't tell anyone but I used the original set of 60ft. until last year! Must have been around 1000 flights. I've still got about 1000 ft of the original reel I bought from Australia.
The only real problem was that eventually that line tends to "fluff up" a bit where they went through the plastic lead out guides. A couple of guys used steel eyelets and had some trouble. A line broke several times when it sawed through the eyelet and frayed.
Another interesting thing during the testing-I used a shorter set for F2D at the NATS. The Mears brothers made a slick "auto" pull tester out of 2x4s. A bent bracket on one end and two weight attachment pins for F2D and AMA made the operation simple. Just lay the handle in the bracket and pull on the plane until the lines lifted the beam.
The most popular F2D lines come from Europe-usually 4 single brass-coated lines of music wire twisted with a fairly long "twist". It is way stronger than the 44 pound pulltest. In side by side pull tests both types of line easily did the pull and in the process they both stretched almost 2 1/4 inches. I don't think there is much to worry about as far as long term strength and durability.
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I successfully tied the modified surgeons knot around a thimble. I did this for the guys that were concerned about fatigue at a line clip. Ill do some testing on break strength today. I think it also satisfies the comments about neat terminations for stunt.
Tom
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Using 100# test maxcuatro . I picked 70#'s of weight and the line broke twice after a few seconds. The termination held even bending the eyelet/thimble.
Tom
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Although not enough data. I would say maxcuatro is 70% of rated claims. I would also say, that real world data wiuld need to be done as to how the termination will react to vibration over time during flight. I will try this setup on a IC beater I have. I will keep inspecting for fraying and report my findings. I think this is promising!
Tom
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Although not enough data. I would say maxcuatro is 70% of rated claims. I would also say, that real world data wiuld need to be done as to how the termination will react to vibration over time during flight. I will try this setup on a IC beater I have. I will keep inspecting for fraying and report my findings. I think this is promising!
Tom
I like what I see here. Did you say that the line broke before the knot on one of your posts? How close to the knot? That is not a good thing. Where did that thimble come from, it could work for more that "Spectra".
ken
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several years ago I was doing strength tests with the braided line and it broke before the rated number. I called the mfg. and spoke to a quality control person about the way they do the pull test. He said they use (I forget the brand name) a force gauge. I have used the same brand in the past and I'm quite familiar with it's operation. Chatillon Force Guage, there I remembered it. It runs very slow, about an inch a minute, and very steady. But the way we are testing is more accurate for the way it's being used.
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Tom,
I like the circle thimble as I feel it spreads the load evenly. I found some small teardrop thimbles (McMaster) that I feel will spread the load even better.
Since you are doing strength testing it would be good if you could describe the test rig and way the load was applied. I would also like to see how the double Uni and double Palomar knot compare.
Another interesting test would be to do a simple ferrule crimp just to see how it compares.
Best, DennisT
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My test was simple. I put 2 35lb. Plates on my pulley system. They did not break near the termination. They both broke about mid span between the cable and the plate mount.
Tom
Maybe I should explain the picture. Im holding yhe thimble between my fingers. The two lines heading up to the spring clip are .027 cable. The two broken lines are on the lower clip. Neither the modified surgeons knot(combat way)or the modified surgeons knot on the thimble failed. The actual line broke. I will repeat the maxcuatro may be not as strong as the standard. Regardless, it broke at 70lbs. Which gives you 140 lb pull test.
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Tom - NICE work! Thanks for sharing.
First off, congrats on the beautifully tied small Modified Surgeons knot. great demo showing the brass eyelets are the failure point! The teardrop eyelets Dennis T found look to be an improvement over the round brass eyelet, but then again, I noticed the knot at the other end of your test line was also the Modified Surgeons knot, tied to a "normal" size, without an eyelet, and no drama at that end!
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Tom - NICE work! Thanks for sharing.
First off, congrats on the beautifully tied small Modified Surgeons knot. great demo showing the brass eyelets are the failure point! The teardrop eyelets Dennis T found look to be an improvement over the round brass eyelet, but then again, I noticed the knot at the other end of your test line was also the Modified Surgeons knot, tied to a "normal" size, without an eyelet, and no drama at that end!
I am really interested to see how they do with the teardrop eyelet. Our old "truth" was that the more you had to bend the line at the point it met the knot the weaker it would be. A round eyelet makes for a pretty sharp bend at the knot. Remember, these knots were originally designed to hold fish hooks. I would think that small rings are a better choice. I don't use either. I tie to the smooth end of the line clip.
Ken
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Gabe and I just did a few quick tests, similar to what Tom did.
The 20lb PowerPro failed right at 20 lbs.
The 65lb PowerPro Maxcuatro failed at 42-45 lbs.
The regular 65lb PowerPro failed at even smaller values, but the exact number was hard to register.
I'm starting to believe that the PowerPro (and possibly other brands too) has to be de-rated to about 70% of its nominal value for the purposes of estimating its actual breaking strength.
By the way, it looks like the link to the modified surgeons knot video posted in the original post is corrupted?
P.S. None of the failures were at the knot; they were in the middle of the line.
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What happen to Mike’s video?? It’s no longer available. 😖
Also why use a thimble? Would it not be better to just tie right to the line clip?
For fishing we tie right to the swivel or hook. K.I.S.S.
Double Uni knot on line clips??????
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What about this knot.
https://youtu.be/kxS7fVOkmDo
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Hi Paul
I sent a note to Mike Stinson about his video, hopefully we can restore access somehow.
In the video you posted the line goes through the hook twice (probably improves that interface) but the Uni knot is tied with the single line strand. In the AMA rulebook , it shows the Uni knot tied with the thread doubled over on itself. That makes the knot much stronger, than just going through the loop twice.
No problem tying the doubled line Uni directly to a line clip. However it makes it difficult to change clips if you are using a hardpoint handle and using different size clips to get your neutral. If you are using a cable handle then no worries...
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Thanks Dennis. 👍🏼👍🏼
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Dennis T:
Careful if you do this, DO NOT heat shrink the tube. Too hard to control the heat, too easy to burn the line. if you want, slip the tubing on as just a sleeve, but no heat or glue.
Question: will acetone or cellulose thinners harm Spectra in any way? If so, what follows is of no use: if not, then I wonder how many people know an old trick I discovered by accident some sixty years ago - immerse ordinary PVC tubing (e.g. the insulation stripped from electrical wiring) in cellulose thinners or acetone for a couple of hours, and it swells and becomes very soft and stretchy (and also rather weak, needing gentle handling). Slip this over whatever you want to slip it over, and leave it. In 12-24 hours, it shrinks back to its original size, feeling a bit harder and stiffer than it was originally. I use this all the time for propeller hooks on my rubber-powered models. Apologies if this is something everybody already knows!
John
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[quote
Also why use a thimble? Would it not be better to just tie right to the line clip?
[/quote]
Some guys have concern about securing to a line clip because of the tight radius. The thimble will spread the load. So far in combat the only area of concern has been where the line passes thru the leadout guide. In time chaffing has occurred, which will cause an eventual failure.
Phil C is really the authority on the knot. He says modified surgeons, thats alright by me!
Tom
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I will have to say, it's about time.
I did some tests 2 winters ago, I made up many 1 foot sections with different knots as termination. I loaded them statically, out of 10 test sections with uni, double uni, granny and Palomar, and granny, none failed at the knot. I was seeing well over 2x the rating on the line.
I do statically pull on a new set pretty hard to set the knot. I clip the tag end after setting the know to 1/16
I only had a line break after a line tangle and the airplane went slack over my head and jerked pretty hard. but the bellcrank pulled out as well
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Interesting link to factoids on spectra and kevlar fibers.
https://www.everprogloves.com/kevlar-vs-dyneema/
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I have been doing a bunch of reading on this. Mostly from the Kite flyers. One problem seems to be fake line. Seems some of the Chinese stuff actually comes in identical packaging as the real. Is there a surefire way to know you are not getting the fake line? ~^
Secondly, since my decision matrix is between Spectra and the Ukraine lines, has anybody done a stretch comparison between the two? My anecdotal experience is that spectra stretches more but the literature says less. It also seems to have more rake but, my ability to do my usual video analysis is grounded. Anybody have any thoughts? D>K
It is hard to pass on something that is lighter, thinner and 15 times stronger but putting your pride and joy out there in a 15mph wind on fishing line sort of bothers me still. Help me get over it! LL~
Ken
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It is hard to pass on something that is lighter, thinner and 15 times stronger but putting your pride and joy out there in a 15mph wind on fishing line sort of bothers me still. Help me get over it! LL~
Ken
I would say the decade of the fast combat guys reliably flying thier Nelson 36 ships at 110-120mph on Power-Pro Spectra should answer the questions on fragility, durability, longevity, ect. That is a really harsh testing environment compared to stunt. Even with the weight differences between a 65oz stunt ship and a Nelson or TWA 36 combat, that 120mph combat ship pulls quite hard.
The drag through the air and amount of perceivable stretch in flight are probably the factors that would dictate choice between traditional .018 stainless, Spectra and the Ukrainian lines for highest level stunt competition.
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The drag through the air and amount of perceivable stretch in flight are probably the factors that would dictate choice between Spectra and the Ukrainian lines for highest level stunt competition.
I have slipped down the ladder of success a bit so I am not exactly at the highest level of stunt competition anymore BUT I like to think that the ladder still goes both ways! I have a couple of sets of the latest Ukrainian lines that I am using now so I guess the next step is make up a set of same size Spectra, have a few beers and give it a shot. ~^
Glad you used "perceived". So mush of trim is wishful thinking. That is why it is nice to have someone less likely to screw up than you are fly your plane every now and then while you take a trip to the port-a-potty so you don't have to watch! LL~
Ken
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Secondly, since my decision matrix is between Spectra and the Ukraine lines, has anybody done a stretch comparison between the two? My anecdotal experience is that spectra stretches more but the literature says less. It also seems to have more rake but, my ability to do my usual video analysis is grounded. Anybody have any thoughts? D>K
Ken
Ken, instead of asking for thoughts or opinions (which many here readily offer), ask for measurements.
It just so happens that I was wondering the same thing, so we went outside today and made some measurements.
Methodology: four types of lines were measured for stretch. Each line (single line, terminated per AMA rules) was anchored firmly at one end, and pulled by the other end using a fish scale using a 20 lb load as a randomly picked load, consistent across all lines. The amount of stretch was measured by observing the displacement of the line end using a stainless steel ruler placed on the ground. A slight preload of 1 lb was applied to the line to straighten it out, then the ruler origin was aligned with the line termination (eyelet or knot), and a 20 lb load was applied. At this load, the stretch was measured against the ruler. Then the measured amount of stretch was divided by the overall line length (different lines came from sets of different lengths), and the elongation percentage was calculated. Here are the results:
Brass plated 4-strand (Ukrainian) 0.0165" elongation 0.5%
Stainless 7-strand 0.018" elongation 0.41%
Stainless 7-strand 0.015" elongation 0.63%
PowerPro Maxcuatro 65# elongation 0.72%
In addition, the PowerPro Maxcuatro 65# line was stressed to failure, and once again we registered a load of about 42 lbs when the line failed (not at the knot).
So, at this point I can say that even though the Maxcuatro 65# will withstand the 10g line pull test, it stretches even more than the 0.015" stainless, and thus is not very attractive for use in full-size stunt planes, despite its low weight and low drag (0.014" diameter).
So far, the least stretchy line that we have tested is the good ole' 18 thou stainless. I don't have other lines to test at this moment. I would be interested to have others perform a similar 20 lb stretch test and report their measurements on other lines (such as PowerPro Maxcuatro 80# or 100#).
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Mike,
Very interesting information, it would be interesting to know the length of the line you tested, what type of clip you used for the terminations and what type of knot and the process you used to tighten, chinch down the knot. Some of these things can impact the stretch, also did you do a pre-stretch to the Spectra line? Some have indicated that once you set the knot you need to load on the line up to 60 -75% of the line rating a couple times then it will be set, then check the stretch.
Bests, DennisT
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Mike,
Very interesting information, it would be interesting to know the length of the line you tested, what type of clip you used for the terminations and what type of knot and the process you used to tighten, chinch down the knot. Some of these things can impact the stretch, also did you do a pre-stretch to the Spectra line? Some have indicated that once you set the knot you need to load on the line up to 60 -75% of the line rating a couple times then it will be set, then check the stretch.
Bests, DennisT
Dennis, I used a single 50 foot long line of the 65# Maxcuatro, terminated with a Uni knot, cinched all the way to the scissor-style metal line clip, and pre-loaded several times. As I mentioned before, there was no problem with the knots: they did not give out, slip, or induce failures.
To make the amount of stretch a little easier to visualize, the 50' line stretched about 4 inches under a 20 lb load. We typically need about 1 inch of line movement to turn a sharp corner.
What I need to emphasize is that the line being tested (65 lb rating, 0.014") was much thinner than is being used in combat, and the line that was tested by Dennis in his original post, which is 100 lb line (0.018"-0.017"). Just as is with the steel cable, it looks like the thicker line is both stronger and less stretchy. I was hoping to capitalize on the premise that the Spectra fiber is stronger than steel, and therefore can be used in smaller diameter, thus reducing the parasitic drag and saving us some battery charge. But it turns out that the amount of stretch at those lower diameters is such that the control feel will be lost, and that's not the price I'm willing to pay for reduced weight and drag.
So, back to the 100 lb line - still lighter, smoother, and stronger than steel, but not necessarily less drag. Oh well, can't have it all.
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Help me understand.......
After reading through hundreds of posts about spectra and associated other brands of fishing line and the attempted use by many for control line flying. I can't find the big advantage that you all are looking for other than slightly lighter in weight. From what I have seen that is the "only" plus in a world of minus as far as it's use. It looks like to get a safety margin I'd be comfortable with, the diameter is going to be the same or larger as stranded stainless or plated steel.
I have been using steel lines for over 65 years from 1/2A to 60 size controline aircraft pretty much trouble free. I make all my own lines and they are easier to make up than fishing line, they stretch very little, and if terminated correctly, last a long time and don't fail. In addition, I can make them dead even every time.
I can make lines from bulk for less money than you're spending on fishing line and can get all the sizes in bulk easily from Melvin Schuette (MBS). He also sells wrapping wire, crimp sleeves, and eyelets. I use those lines for everything from 1/2A(.012") to fast/slow combat (.018") to my stunt airplanes (.015"). For F2D aircraft I use pre made lines from the Ukraine (.0154" x 52'2.77")as we go thru some due to tangles, crashes, etc and they are very inexpensive @ $6/set ready to fly. These lines on an F2D are pull tested at 45lbs for an airplane that weighs about 18 oz RTF ( yep, that's about 40G's)
So, what am I missing that motivates you to fly fishing line?
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[quote Some guys have concern about securing to a line clip because of the tight radius. The thimble will spread the load. So far in combat the only area of concern has been where the line passes thru the leadout guide. In time chaffing has occurred, which will cause an eventual failure.
Phil C is really the authority on the knot. He says modified surgeons, thats alright by me!
Tom
I sheathe the part of the clip where the line goes round, using the trick described in my earlier post. It's fiddly, manoeuvring the soft, floppy PVC tubing into place on the clip, but when it hardens it increases the diameter of the clip to a useful extent. Also, it's not going to be as potentially abrasive as the wire of the clip itself.
John
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Hello In reply to some of Don's questions I think better quality steel lines will still have the drag advantage over Spectra for F2b as you need 80 or 100lb line to reduce the stretch , I found 65lb stretches too much for medium or large models.
Spectra will probably become the line of choice world over for general sports flying and slow combat where rules allow it. This is because the lines feel nice and light and the model changes direction easier but you need to try them to see the difference. The lines only take about 5 minutes to make up, which I can say after videoing this process recently after making over 20 sets now. They are very cheap if you buy a big roll and very durable in combat and general use surviving tangles and trip overs better then anything else I have used.
I think there has been some poor quality line out there perhaps falsely rated, marketed or packaged but the Power Pro Max Cuatro I have used has been good and tested well but on the other hand other brands of line I have experimented with have proven surprisingly good too.
One thing nobody has mentioned as a down side that infuriates me with Spectra is its ability to get tangled up in twigs and small branches or stuck to bark on trees if blown by the wind but this normally only happens on ruff sites or windy days due to its fibrous nature and light weight.
My sons and wife always prefer to fly Spectra where rules allow but few locals around us fly it let alone try it .
Regards Gerald
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When I first heard of Spectra and similar materials for lines, I was interested enough to do my own tests, as others have done. I was looking for an alternative to the stranded steel lines and it looked like Spectra was the way to go.
It has been a few years now since I messed with Spectra lines. The Power Pro is the only version I have tried so my experience might not be applicable to other brands of similar material. At that time, these lines were not approved for use in the events I fly. Therefore, I saw no reason to go any farther with them after my testing period and I gave up on them. Any notes have been lost since then and I have to rely on memory here.
After doing pull tests and flying with these lines, I am on the fence. Yes, there are advantages--less weight, less susceptible to damage from walking on them and getting kinks, faster to make up a set.
But, there are disadvantages, at least for me. One negative aspect was the greater drag. The bow in the lines was far greater than with stranded steel lines. How does that affect leadout position? I never figured out how to deal with that greater drag.
I did pull tests on lines of different rated strength. Most of the testing was with the 65 pound and 80 pound line. From what I remember, the line broke at approximately 60% of the rated strength. The line never broke right at the knot. It usually broke about an inch or two inches from the knot. The only knot I used was the Uni knot. I seem to remember that the Uni knot was the approved knot as stated in the rules at that time for general use and sport flying with Spectra.
I also did some stretch tests, using a metal scale taped to the sidewalk to measure stretch. The Spectra stretched more than steel lines. I can't say exactly how much more since my notes are gone but I do remember being disappointed in that there was no advantage there over the steel lines.
After doing my tests, I see no clear advantage to using Spectra, at least for my use. But, others might find them acceptable and possibly superior to the steel lines.
If time permits, I will look into more tests with the newer products and maybe I can be convinced to use them.
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....but few locals around us fly it let alone try it .
Regards Gerald
This seems to be universal!
I sheathe the part of the clip where the line goes round, using the trick described in my earlier post. It's fiddly, manoeuvring the soft, floppy PVC tubing into place on the clip, but when it hardens it increases the diameter of the clip to a useful extent. Also, it's not going to be as potentially abrasive as the wire of the clip itself.
John
Can heat shrink tubing be used for this? It seems like a really good idea. My experience mirrors Jim's minus the break testing. My use test was before I switched to the Ukrainian lines and well before their newer offerings. I concluded that they were usable but I did not want to practice with something I could not use in competition. I am glad we have the new rule though, it makes sense and will no longer be the roadblock to innovation.
Ken
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We seem to be getting into analysis paralysis talking about the stretch of the lines. Most people doing stretch tests have been using a pull of several times what would normally be expected from a stunt ship. Most ships pull less than 8 lbs. at the speeds we fly. The other thing to consider is that this load is applied over two lines, so the actual line area is double. If you are looking for an excuse not to use Spectra lines you can say they stretch too much at 10x the model weight, that's OK. But in reality, at normal flying pull, it is not a real issue.
The lighter weight, durability and thinner diameter on the newer smooth 8 braid Spectra lines will reduce line load and can help reduce fuel/amps needed, which in turn reduces model weight. Seems we need to be looking to find the brands with the most strength, least stretch and strongest, most reliable termination rather than worrying about a non-critical issue.
Best, DennisT
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We seem to be getting into analysis paralysis talking about... AMEN!
Best, DennisT
In my case my next flights may not happen until May. I am not terribly concerned about strength of line or knots, my main parameter will be stretch. I will be testing 80# Maxcuatro back to back with original Power Pro 100# which I know works. If my airplane pulls 8 lbs then I will be loading my lines (2 x 80# capacity) to 5% of there rated load. I think it will be OK. If I do not like the Max 80#, then I can either try Max 100#, original PP 80# which both have larger diameters (and presumably less stretch), or just go back to the original PP at 100#. Likewise I will be testing Maxcuatro 50# versus Suffix 832 65#. Same story line with 3 ways to get to a higher diameter.
BTW, I got an eye-opener last fall when I was doing the pre-stretch on a bunch of Spectra lines. I tied them to a tree then held them with a handle at the other end. Pulled what I though was a 30-40 pound load and held it while I counted to 100, all the time also wiggling the handle just a little to introduce a bit of a dynamic loading. The lines felt stretchy. Then for comparison I tried the same thing with my .018" 7-strands, they felt at least as stretchy. The next day's flight test confirmed that observation.
In other news I found a few videos of a guy testing breaking strength of various sizes of Maxcuatro. His test device looks good, his results show reasonable repeatability, and his numbers show breaking strengths higher than rated line strength. When I first found these tests it gave me confidence that Maxcuatro would do the job. I have no explanation as to why Tom & Mike got much different results than the guy in these videos below. Maxcuatro was been getting the most discussion here, but he also has tests on other brands. If you are interested, the results he calls "ABS Test" focus on the line independent of any knots. He also tests the lines when knot to a leader line but that does not apply to us at all:
* Maxcuatro 20# line, broke around 35 lbs, see vid:
https://www.youtube.com/watch?v=ozEwsNQdy9M&t=332s
* Maxcuatro 30# line, broke around 49 lbs, see vid:
https://www.youtube.com/watch?v=PF74lRF02bM
* Maxcuatro 50# line, broke around 58 lbs, see vid:
https://www.youtube.com/watch?v=xO-y27UAcjQ&t=75s
* Maxcuatro 65# line, broke around 76 lbs, see video:
https://www.youtube.com/watch?v=AoqnhK8owYk
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It is interesting to see how the same information gets digested and interpreted by different people.
Some think that persistent experiments to find the optimum line brand, type, diameter, knot, etc. is evidence that we want everyone to switch to a particular type of line at all costs, ignoring the decades of relatively successful experience with the steel line.
Others interpret posted numbers as evidence that we want to shut down the nascent technological trends (Spectra) before giving them a chance to succeed.
As an engineer, I've been trained to look at numbers as just that - numbers, quantitative indicators of some physical property (mass, volume, density, conductivity, tensile strength, etc etc), and leaving any emotions out of the process ("oh look how cool this carbon fiber weave would look on this crockpot lid!" or "I hate anything aluminum"), apply an engineering reasoning process to a decision process while considering all available alternatives.
In this case, Dennis Adamisin has reported a number of performance improvements when switching from 0.018" stainless cable to a 100# Maxcuatro braid (lighter, stiffer, more slippery line, needing less tip weight). The combat folks have evidence that the line is also durable and more abuse-resistant. This by itself is good enough for me to invest some time and test for myself. I went a step further and asked a question, can we achieve yet another benefit of using a thinner line that is still 10G- pull compliant (65#). The experiments showed that while we will achieve less drag, the added stretch is not worth the trade.
That's all. Finding an optimal solution through a series of experiments and compromises, using measurements (and not feelings or opinions) as guidance.
And sharing the results on this forum is just a means of contributing to the stunt community by not making others go through the same expensive and time-consuming path. This is NOT an attempt to sway or convince anyone to either change anything they've been doing, or to stay with the status quo. Just as I'm not trying to make anyone stop building balsa airplanes by extolling the virtues of composite technology, or switch combustion aficionados over to electric. Everyone is entitled to their own preferences.
I have a spool of 100# Maxcuatro on order.
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If the drag of the Spectra lines can be reduced, that would be a big plus for me. I would have to get some of the newer product, the thinner line but with strength equal to something thicker, and see how that compares to what I experienced in the past regarding the drag issue.
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I really think we need to look at the newer 8 strand braid lines as opposed to the original 4 braid lines. The 8 braid line should be smoother (less drag) and offer a bit of a safety indicator as you can lose a few strands, get a fuzz-up indication of the failure and still have a lot of strength in the line to get down safe. There is also a fused line that I want to learn more about the strength of, which are very smooth but not sure of the strength to diameter on these.
There is a 9 braid line, Berkely X9, that is a 9 braid that seems to be very smooth and strong here is the chart of lines specs: https://www.berkley-fishing.com/products/x9-braid-1486839?variant=34171397275787 the break (https://www.360tuna.com/threads/berkley-x9-20-lbs-crystal-abs-fg-and-pr-knot-test.56204/) at the first part of the video on just the line, the rest is line splices to mono.
There is a very high-end 16 braid line (GOSEN 16) which reported to be the smoothest line made, about 3x the price of the 8 braids but for our use might be worth looking into.
Best, DennisT
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Interesting article comparing 4-strand and 8 strand spectra/dyneema lines. Sadly, there is no mention of use with control line airplanes...
https://www.sportfishingmag.com/comparing-4-and-8-carrier-braided-fishing-lines/
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Hello Some interesting information coming up here, was keen to try Power Pro 'Super Slick' or the 'Fins' 8 strand line but Brent's article at Sportfishing sounds promising particularly :
"Burch believes he might have the next evolution in braid with FINS’ latest nine-carrier 40G product. “The center of the line is Spectra High Tenacity fiber with eight ends of PE wrapped around it,” he says. “Spectra HT is 25 percent stronger and 30 percent smaller than traditional deniers of Spectra fiber. It is the smallest diameter-to-strength ratio we have ever offered.”
I suppose I really need to try out a few new products to see if something beats Maxcautro
Ordered some Fins 40G in blue in 65 and 85 lb will see how this works
https://youtu.be/7vesKRPri4c
Regards Gerald
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I ordered a spool of the FINNS 40G 45LB, should be very strong, smooth and round with the 8 braids. I was wondering if the form of the braid has a significant impact on the line drag through the air. What I mean is the outer bumpiness of the number of braids. It seems that not only does the thickness matter, but the smoothness of the round shape.
I'm thinking that thin is good but thin and closes to what a solid round wire form would be less drag and require less amps to pull the line around. What I would like to get to are lines that are strong enough, light (to allow reduced needed tip weight) and as thin or thinner than if I flew on solid steel (reduce line drag and amps). It seems there is still work we can do to get better termination that meet our needs which are different then fishing needs.
Best, DennisT
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Well I did it! I made my first set of Spectra line using Power Pro Maxcuatro 65 lbs. These lines are for a 39 oz. plane were I currently use .012" x 60' stainless steel lines. The 65 lbs. Spectra lines is an overkill for this size of plane. However, I am more interested in how these lines stretch and did not want to risk my primary plane for testing.
Before making up my set of lines I purchased a couple of items to assist in addition to the Spectra lines. The first item is a Berkley Hot Line Cutter. I purchased mine at https://sportco.com/berkley-hot-line-cutter/ (https://sportco.com/berkley-hot-line-cutter/) for under $11, including shipping. This uses two AA batteries and heats a retractable wire element that cuts or melts the Spectra line. The benefit of this is that it cauterizes the ends of the lines and keeps them from fraying.
The other item purchased was a portable LED Fish Scale (or Luggage Scale) from eBay for under $10. This scale can handle up to a 100 lbs.
The last item was some Fishing Solid Stainless Steel Ring Connectors (not the split ring connectors) at Walmart. I got 50 of the small size that are rated for 150 lbs. More on this later.
Mike Stinson updated his video on YouTube on how to tie a set of Spectra lines:
https://www.youtube.com/watch?v=d1l_fAPV6lA&t=1s (https://www.youtube.com/watch?v=d1l_fAPV6lA&t=1s)
I tied a set of lines with the modified surgeons knot at each end exactly 60' from loop to loop prior to stretching. I then stretched of each line at 50 lbs. for 1-minute using LED fish scale. I did each line twice. BTW, you get a good workout when doing this. I re-measured the lines and to my surprise each line stretched and additional 2 1/2"! Lesson learned: Stretch your lines before using them!
The Berkley Hot Line Cutter works pretty well. It requires that you have some tension on the line that you are cutting. It take a few seconds for the wire element to heat up. Once it heats up it cuts through the Spectra lines like butter. However, be very careful not to get the hot wire element near you main line.
Attaching the lines to the plane I use what are called stainless steel Quick Change Hawaiian Snaps. I attach the Spectra lines using what the StuntHangar Hangout gang has now affectionately called a Lenny Loop, which is nothing more than a "Lark Head" knot and added a 1/4" long piece of surgical tubing over the snap to keep the Spectra line in place. Again look at Mike Stinson's video.
On the handle end I ran into an issue. I use a Cox/Resinger carbon fiber handle with line clips made using the Derek Moran Line Clip Bender tool. The holes in the handle can only pass the single loop end of the clip which leaves the doubled up portion of the line clip to attach the Spectra line to. I didn't have any surgical tubing large enough to pass over the clip to hold the spectra line in place. So for the time being I'm using the solid ring connector to connect to the spectra line and connecting the solid ring connector to the line clip. I plan on switching the connectors on my handle to the "Kitty Clips" that use a spring retainer.
The last thing I did was another 1-minute 50# pull test of everything including, the handle, all connectors and the Spectra lines, everything with except to the plane. The Spectra lines did not stretch any further.
Hopefully, I will get some good weather and put everything is the air. Stay tuned...
Dennis
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I tied a set of lines with the modified surgeons knot at each end exactly 60' from loop to loop prior to stretching. I then stretched of each line at 50 lbs. for 1-minute using LED fish scale. I did each line twice. BTW, you get a good workout when doing this. I re-measured the lines and to my surprise each line stretched and additional 2 1/2"! Lesson learned: Stretch your lines before using them!
[...]
The last thing I did was another 1-minute 50# pull test of everything including, the handle, all connectors and the Spectra lines, everything with except to the plane. The Spectra lines did not stretch any further.
Dennis
Dennis,
I would be curious to see if your lines "shrink back" by the full 2.5" or some fraction of that stretch over time (a week? a month?). Most polymers have such tendency, and I wouldn't be surprised if Spectra (polyethylene) is not an exception. 2.5" is a significant enough value, because uneven stretching or shrinking between the two lines might cause some serious problems with the neutral setting. I know we fuss sometimes over 1/16" neutral adjustment...
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Dennis,
I would be curious to see if your lines "shrink back" by the full 2.5" or some fraction of that stretch over time (a week? a month?). Most polymers have such tendency, and I wouldn't be surprised if Spectra (polyethylene) is not an exception. 2.5" is a significant enough value, because uneven stretching or shrinking between the two lines might cause some serious problems with the neutral setting. I know we fuss sometimes over 1/16" neutral adjustment...
Less than that, I routinely adjust by 1/64" or so just depending on how I am feeling the inside/outside turn difference from day to day. It's probably adjusting for something else changing, but handle adjustments are easy and predictable.
Brett
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Less than that, I routinely adjust by 1/64" or so just depending on how I am feeling the inside/outside turn difference from day to day. It's probably adjusting for something else changing, but handle adjustments are easy and predictable.
Brett
OK, agreed, even small neutral adjustments down to 1/64" can be felt.
At this point, from what little I know about the Spectra braided lines, the issue of stretch memory, or "line length consistency" if you wish, is the most significant issue that threatens to make these lines unusable for us in competition stunt - not the drag, the breaking strength, knot strength, or many other things that have been discussed earlier.
If I can't rely on the lines to maintain their length to, say, 1/64" flight after flight, week after week, then we're back to steel. I don't know too many competitive flyers who would be willing to put up 6-8 flights to compensate for the ever changing neutral before starting their weekend practice.
This is my thinking at the moment, and is mostly conjecture and speculation. I haven't made "stretch memory" measurements, and given the weather forecast, I may not be able to get to making any measurements for a while, it's just too cold outside. Guys in warmer climates might get to it before I do...
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OK, agreed, even small neutral adjustments down to 1/64" can be felt.
At this point, from what little I know about the Spectra braided lines, the issue of stretch memory, or "line length consistency" if you wish, is the most significant issue that threatens to make these lines unusable for us in competition stunt - not the drag, the breaking strength, knot strength, or many other things that have been discussed earlier.
I am certainly not arguing with you, it is very interesting (as has been the rest of this most excellent thread). I have flown 3 flights with Spectra, all on the Skyray, so that is nearly nothing.
Brett
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I'm more interested in the range of expected stretch at typical flight loads, not 10x.
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I'm more interested in the range of expected stretch at typical flight loads, not 10x.
Yeas, I'm watching this thread with interest also. I have bought some line with the intent to just use it on my "foo foo" fun fly airplanes and some small models. Just so I don't have to worry about messing up a set of steel lines as what they cost now. It makes sense for just fun flying. I'll keep with steel lines for competition airplanes for now. I have been doing far more fun flying than contest flying the last several years.
Type at you later,
Dan McEntee
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I'm more interested in the range of expected stretch at typical flight loads, not 10x.
At 10G, you would get similar elongation on .018 7-strand.
Brett
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At 10G, you would get similar elongation on .018 7-strand.
Brett
But does it stay? I have never checked that. On an initial pull test to "set" a new set of lines, I would expect some sort of change, but I have never measured. I can feel they stretch a bit like a spring action, but never did think much of it.
Type at you later,
Dan McEntee
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But does it stay? I have never checked that. On an initial pull test to "set" a new set of lines, I would expect some sort of change, but I have never measured. I can feel they stretch a bit like a spring action, but never did think much of it.
Type at you later,
Dan McEntee
No, it goes back (for the most part). But if you are interested in it relaxing between uses, you might have an issue.
Brett
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should be very strong, smooth and round with the 8 braids. I was wondering if the form of the braid has a significant impact on the line drag through the air. What I mean is the outer bumpiness of the number of braids. It seems that not only does the thickness matter, but the smoothness of the round shape.
Interesting point although a non-smooth surface can be often less draggy than a smooth one! Compare a dimpled golf ball against a smooth one - the former flies further with a better flight profile compared to the latter! Think of full-on, glossy paint against the semi matt versions seen on recent F1 race cars - it was found the latter experience significantly less drag when compared. It goes against 'common sense' but boundary effect on un-smooth surfaces can be a thing to consider as maybe a benefit not a hindrance?
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At 10G, you would get similar elongation on .018 7-strand.
Brett
Even the tinned 3-strand 'Laystrate'-type lines in common use in England have a noticeable stretch on a 10G pull test.
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Interesting point although a non-smooth surface can be often less draggy than a smooth one!
Hold that thought, this is the wrong thread but finally! I have been trying to convince folks for as long as I can remember that my planes fly better with a matt finish than they do buffed. I started a new thread so this one doesn't get hijacked.
Ken
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Dennis N - THANKS for sharing your line stretch results you proved the need for pre-stretching! I am even going to buy a pull scale so I can do a better job of controlled pre-stretch than I have in the past. Being lazy, the one thing I might change is to connect the lines end to end and pull them at the same time to assure exactly the same load - in half the amount of time!
From what I have heard the Combat guys do the stretching ONCE then forget about it. However, Mike Alimov raised the point about polymer "memory" (stretching then reverting), but I wonder if at least part of the effect of stretching is simply to align the strands and tighten the weave of the braid? Also if Mike is right then we made want to periodically repeat the stretching exercise to correct whatever the amount of stretch is caused by polymer material stretch?
I know SS cables & even solid lines stretch, can't help thinking that we SHOULD have been pre-stretching SS cables all along.
In those line strength videos I posted (reply #59) I noticed that the tester first loaded the line to around 50% then held it for a few seconds, before continuing to load the line to failure. I suspect that the tester was letting the weave tighten up as the strands got aligned - which probably improved the ultimate failure point. Similarly, I wonder if when knotting the line it is possible to inadvertently get more tension on one or two strands, causing them to fail first, even if it is away from the knot, with that failure cascading across the remaining strands? If so then pre-stretching & holding the load (per Dennis N) should help the strands align and increase breaking strength. Note: this might also explain some of the tests that show line breaking below its rated strength?
I am past deciding whether I will use Spectra, and expect that concerns with stretchiness will be answered over a couple sessions at the flying field. My biggest concern before flying season will be removing all the built in tip weight I have pre-installed. I do this so I can use the tip weight box for fine tuning. However, I cannot remove enough from most of the fleet! Those airplanes with large asymmetry (Classics & OTS) may need INBOARD tip weight boxes..!
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I am not positive how many wraps our lines get during the course of a pattern. I do know that, depending on how you do the Reverse Wingover you end up with three. The wrapping causes friction and ware on the lines. On the Ukranian lines you can see that ware as a slight dulling after 10 or so flights. I haven't used Spectra enough with the same line to know how it reacts and if the effect on controls is any different. Just how far from the plane the wrap occurs may also be quite different.
Brave new world - Ken
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Dennis,
I would be curious to see if your lines "shrink back" by the full 2.5" or some fraction of that stretch over time (a week? a month?). Most polymers have such tendency, and I wouldn't be surprised if Spectra (polyethylene) is not an exception. 2.5" is a significant enough value, because uneven stretching or shrinking between the two lines might cause some serious problems with the neutral setting. I know we fuss sometimes over 1/16" neutral adjustment...
Hi Mike,
I re-measured my lines today, 24 hours after the initial stretch, and the 2 1/2" increase in line length remained the same. It's difficult to "accurately" determine how much these lines either increased or decreased in length. I'm trying to maintain the same amount of tension on the lines with each measurement but it could be off 1/8" or so either way and who knows what my 100' steel tape measure is doing. But it definitely *did not* shrink back the full 2 1/2"! I'll measure again in a week or so and see if there are any significant change.
Dennis
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Pre-stretching the Spectra is something I never did, at least not with that as the primary purpose. All I ever did with Spectra or stranded steel is to proof load them to the pull test load after making up the line set. That is, each line was pulled to 1/2 of the 10G requirement. Maybe the proof loading produced the necessary pre-stretch.
I never went back to measure the Spectra after I did my proof test to see if the lines remained stretched. For that matter, I never did it with the stranded steel lines, either.
On the stranded steel lines, I could certainly notice the stretch and when the load was removed, the lines went back to what I assume was original length. I would expect that to be true as long as I did not exceed the yield point of the material. I have not messed with Spectra for quite some time and I can't remember if it behaved like the steel lines after proof loading.
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Hi Mike,
I re-measured my lines today, 24 hours after the initial stretch, and the 2 1/2" increase in line length remained the same. It's difficult to "accurately" determine how much these lines either increased or decreased in length. I'm trying to maintain the same amount of tension on the lines with each measurement but it could be off 1/8" or so either way and who knows what my 100' steel tape measure is doing. But it definitely *did not* shrink back the full 2 1/2"! I'll measure again in a week or so and see if there are any significant change.
Dennis
. Dennis are you sure that the line stretch? or is it the knot tighten ?
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. Dennis are you sure that the line stretch? or is it the knot tighten ?
No the knots were tight, it was the line.
Dennis
Sent from my iPhone using Tapatalk Pro
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OK, found some very interesting information about knot strength and how it affects the breaking strength of the braid line. The weakness of our uses of Spectra is having confidence in the selecting the proper LB test line and not overkill. With good knots we can go closer to 10X the model weight for the LB test line and likely have thinner lines.
Here is the site: https://www.knotsforfishing.com/strongest-braid-knots/
Scroll down and it has link to each type of knot. Now we need to figure out which of the 100% plus knots to use. The "Burke Knot" on the list just a double Uni knot that AMA recommends.
Best, DennisT
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OK, found some very interesting information about knot strength and how it affects the breaking strength of the braid line. The weakness of our uses of Spectra is having confidence in the selecting the proper LB test line and not overkill. With good knots we can go closer to 10X the model weight for the LB test line and likely have thinner lines.
Here is the site: https://www.knotsforfishing.com/strongest-braid-knots/
Scroll down and it has link to each type of knot. Now we need to figure out which of the 100% plus knots to use. The "Burke Knot" on the list just a double Uni knot that AMA recommends.
Best, DennisT
For me, line strength and knot strength are lesser of a determinant than the line stretch characteristics in use. Much like flying a 60oz piped ship on .012 or .015. stainless stranded lines. Yes, you can, but the flight performance will suffer greatly compared to a line material or diameter that exhibits less elasticity. So, yes, you could probably safely use 40lb spectra with a 100% strength knot on a big plane, but the performance aspect would likely suffer compared to 80-100lb line on a big stunt ship.
Is there a problem with the knot the combat guys have tested, vetted and widely used for a decade?
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I have been doing a bunch of reading on this. Mostly from the Kite flyers. One problem seems to be fake line. Seems some of the Chinese stuff actually comes in identical packaging as the real. Is there a surefire way to know you are not getting the fake line? ~^
Secondly, since my decision matrix is between Spectra and the Ukraine lines, has anybody done a stretch comparison between the two? My anecdotal experience is that spectra stretches more but the literature says less. It also seems to have more rake but, my ability to do my usual video analysis is grounded. Anybody have any thoughts? D>K
It is hard to pass on something that is lighter, thinner and 15 times stronger but putting your pride and joy out there in a 15mph wind on fishing line sort of bothers me still. Help me get over it! LL~
Ken
I posted up above, at the NATS I used an "official" pull tester Bob and Andy Mears built. Anyway brass plated, 4 strand Ukrainian lines managed the 44lb. pull test and stretched 2-1/4 inches. The braided, .175 Australian line, from around 1993 pull-tested fine and stretched 2-1/4 inches. One really nifty feature, for combat, in a line tangle the metall lines lock up with one wrap. The rough surface can't slide until the Spectra line unwraps.
The braided line does bow more which generally isn't a problem as long as the LO guide and sweep is allowed for.
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We seem to be getting into analysis paralysis talking about the stretch of the lines. Most people doing stretch tests have been using a pull of several times what would normally be expected from a stunt ship. Most ships pull less than 8 lbs. at the speeds we fly. The other thing to consider is that this load is applied over two lines, so the actual line area is double. If you are looking for an excuse not to use Spectra lines you can say they stretch too much at 10x the model weight, that's OK. But in reality, at normal flying pull, it is not a real issue.
The lighter weight, durability and thinner diameter on the newer smooth 8 braid Spectra lines will reduce line load and can help reduce fuel/amps needed, which in turn reduces model weight. Seems we need to be looking to find the brands with the most strength, least stretch and strongest, most reliable termination rather than worrying about a non-critical issue.
Best, DennisT
It's a good idea, but not absolutely required to stretch Spectra lines to set the braid or twist. About 50% of the listed pull test on the package usually is enough.
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I posted up above, at the NATS I used an "official" pull tester Bob and Andy Mears built. Anyway brass plated, 4 strand Ukrainian lines managed the 44lb. pull test and stretched 2-1/4 inches. The braided, .175 Australian line, from around 1993 pull-tested fine and stretched 2-1/4 inches. One really nifty feature, for combat, in a line tangle the metall lines lock up with one wrap. The rough surface can't slide until the Spectra line unwraps.
The braided line does bow more which generally isn't a problem as long as the LO guide and sweep is allowed for.
Was the line lying on the ground the whole time during the pull test, or suspended?
If the latter, then a lot of that observed "stretch" could just be the catenary curve moving up under tension.
I make up F2D lines to the correct length with zero pull, laying on the ground. If they actually stretched 2-1/4" during a pull test, I probably would have seen it at some point since the length tolerance is less than that.
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"One really nifty feature, for combat, in a line tangle the metal lines lock up with one wrap. The rough surface can't slide until the Spectra line unwraps."
You think that's "nifty"??????
That's why they aren't legal in F2D and a mix of synthetic vs metal should never be allowed in competition. Two reasons; Metal lines tend to lock up in a tangle but: if the planes fly with tension for more than a few seconds while tangled the spectra lines will fail. I have seen it multiple times.
Ask yourself why fishermen going after tough fighting fish use the synthetic line but use a braided steel leader. Answer, it sucks under abrasion or sharp object encounters.
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I like Mike Stinson's video on tying the knots, seems to make it fairly easy to get the line length correct enough. The knot looks like it does not over stress the line when tightening and can hold up to the rated LB test of the line, all good. One thing I would like to see if Mike could show how he gets the clip loop knot very close to the clip. I don't like the loop being able to slide around on the clip as I feel this will be a wear point. If it is tight up against the clip it could bent but not slide would seem to be a one less wear failure point of worry about.
The point raised by Katana about the dimples on golf balls is interesting. It makes sense that the super smooth lines may not be the least drag. Seems we need to do a flight test of both types side by side.
Best, DennisT
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One thing I would like to see if Mike could show how he gets the clip loop knot very close to the clip. I don't like the loop being able to slide around on the clip as I feel this will be a wear point. If it is tight up against the clip it could bent but not slide would seem to be a one less wear failure point of worry about.
Hi Dennis,
One of the methods for attaching the Spectra lines to the line clip when using the modified surgeon's knot is a "Lark's Head" knot or what the StuntHanger Hangout Group calls a "Lenny Loop". This can help hold the line in place and is stronger than just using just the two loops.
The combat guys have been using Spectra lines for several years and apparently like them. But the expectant life span of a combat plane, in most cases, is relatively short lived when compared to a stunt ship. I'm curious, how often do combat flyers replace their Spectra lines if there not involved in an incidence?
Dennis
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I tried Dennis N's suggestion to use the Larks Head to attach the scissor line clip to the Spectra with the double Surgeons termination, it works great!! Solved my concern about the line moving around on the clip.
The Larks Head is used by the Kite flyers and is simple to apply. Simply take the double loop created by the double Surgeons knot (MS illustrated in his video), pass it though the line clip (you could go around twice if you have a big loop) and bring it under around the bottom of the line clip. Then open the loops and pass the end through the loops and up over and around the clip, pull tight and BAMB it is cinched down. This secures the line and neither stress the Spectra as they are formed.
Thanks for the suggestion Dennis N.
Best, DennisT
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The combat guys have been using Spectra lines for several years and apparently like them. But the expectant life span of a combat plane, in most cases, is relatively short lived when compared to a stunt ship. I'm curious, how often do combat flyers replace their Spectra lines if there not involved in an incidence?
Dennis
Mike Londke, Phil Cartier and other users report that generally, combat fliers replace thier Spectra lines annually as a matter of seasonal maintenance or combat readiness. The primary reason for the annual replacement of the Spectra lines is because many of those combat guys attach the lines directly to the bellcrank. This arrangement causes very localized wear on the Spectra line material as it constantly rubs on the leadout guides. The wear pattern is described as fluffing, fuzzing or fraying.
This type of wear is simply something that does not occur on a stunt plane with traditional leadouts. I do not believe annual Spectra line replacement is necessary for Stunt use. As with any of the metal line materials in use, inspect your lines often and replace as needed.
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I was able to sneak out at lunch today and take advantage of a "balmy" 40-degree day to make some more measurements, now adding the newly arrived 100# Maxcuatro into the mix. First I measured "virgin" line elongation, i.e. the line as it just comes from the factory spool, with no previous load applied. Then, using the knowledge gained from Dennis Nunes' experiments, I added the procedure I will refer to as "conditioning", which involves applying progressive load up to 30 lbs, and holding this load for 1 minute, repeated two times, which sets all the knots and stretches the lines. The lines do indeed stretch out some, in my case about 1.25". I did not want to apply more than 30lbs of conditioning tension because I expect that if lines are stressed to 80-90% of the rated breaking strength, two things can happen: knots will fail, and/or the line will relax somewhat, changing the elongation properties and rendering original results useless.
I also discovered a mistake in my earlier reported measurement, so the new set of corrected numbers is here:
Brass plated 4-strand (Ukrainian) 0.0165" elongation 0.5%
Stainless 7-strand 0.018" elongation 0.41%
Stainless 7-strand 0.015" elongation 0.63%
"Virgin" Maxcuatro 65# elongation 0.79%
"Conditioned" Maxcuatro 65# elongation 0.65%
"Virgin" Maxcuatro 100# elongation 0.55%
"Conditioned" Maxcuatro 100# elongation 0.45%
(While I haven't tested it, I expect 80# Maxcuatro to fall somewhere in between 65# and 100# results).
Preliminary conclusions:
- after "conditioning" and with properly terminated ends, Maxcuatro lines with ratings from 65# to 100# will comfortably pass 10G pull tests for planes in the 55 - 65 oz range, with a 2X-3X safety margin;
- after "conditioning", Maxcuatro 65# line is expected to give about the same stretch feel as a 7-strand stainless 0.015" cable, and has comparable diameter;
- after "conditioning", Maxcuatro 100# line is expected to give the stretch feel between a 7-strand stainless 0.018" cable and a 4-strand 0.0165" cable, and has comparable diameter to 0.018" cable;
So far, the only performance advantage over the steel lines is smaller weight of the Spectra lines; the rest of the advantages fall into the usability category: kink resistant, hydrofobic, easy to see, etc. The ability to control after 40 loops and come out of a line tangle without damage are not of interest to us for stunt application.
What remains unanswered is to what degree will Spectra-based lines maintain their length, and their elongation properties, over time as well as under different environmental conditions.
Specifically, here are the example scenarios that worry me:
- A user stretch-conditions his lines, performs a few trimming flights to dial in the neutral, and starts practicing; then a month later he goes to a contest, where a contest official performs a 10G line pull; somehow one of the lines stretches a little more than the other - but the user is unaware, until he goes into official flight, and is unable to deliver his best results due to the neutral being off;
- At a contest, a user passes the 10G pull test, performs the first flight of the day, and then puts down the lines on a hot tarmac to wait for the second round flight; the heat shrinks one of the two lines a little more than the other - once again, the neutral trim is lost, and a good flight cannot be performed.
The time and temperature study is difficult to do by using measurements: as Dennis N. noted, how do you accurately and repeatably measure a length of nearly 70' down to 1/64" accuracy (or better) over the course of days, weeks, and months? Of course this could be done by someone with a very keen sense of neutral, flying a plane with the same set of lines and same handle over a long period of time, but I'm not one of them - my neutral can be off by 1/8" and I'm still OK with it.
As of today, I'm still on the fence about adopting these lines.
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Very good information Mike. Hopefully I will get to test the 80# Maxcuatro lines this Saturday to see how they perform. However, my test will be performed on a plane that only weights 39 oz. The 80# Maxcuatro line I believe is an overkill for this size plane. Currently, I use.012" x 60 7-strand stainless steel lines. For the first flight I plan on flying the plane with the stainless steel lines and then the very next flight switch over to the Maxcuatro lines and see if there is a difference. One of the things I'm curious about is if the 80# lines are too large and how much it effects the performance. Will see...
One of my concerns is when we "condition" a set of lines, how much will the break point of the line drop. I'm no Structural Engineer (but I can play one on TV ;D). I would think that as a result of conditioning, the break point of the line is lowered. How much is what I'm concerned with.
Dennis
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One of my concerns is when we "condition" a set of lines, how much will the break point of the line drop.
Dennis
Based on a few destructive tests that Gabe ran on the 100# Maxcuatro last night, the breaking strength is actually increased after "conditioning". I'm not ready to report by how much, but it definitely doesn't deteriorate.
I'm no longer discussing the breaking strength as part of our tests because at 4X-5X margin, does it really matter? We are using 80-100 lb line to withstand a 20 lb pull test and a 5 lb normal flight load.
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Tried Mike S knot and found that if you take a very thick piece of twine to practice with it is much easier to get the hang of which way the bite loops are pushed through the initial loop. Once you do it with the twine you can do the fine line. Got half a set done will complete tomorrow.
Best, DennisT
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Based on my still limited experience with Spectra, and after a thorough analysis of the test results posted here and other online sources, I have narrowed my new line purchase to the single best line for a particular airplane of mine. The airplane and the line in question are shown below:
(eat your hearts out)
Seriously folks, read through the posts in this threads, I think it is pretty easy to pick/choose a line for your own trials and your own in-flight prove-out... Choose your line, tie it as indicated above, condition the line by pull testing to 50% load for 1 minute, and fly it. I suggest you fly with an old familiar airplane on cables first then switch the next flight. If you like it try it on the rest of your fleet...
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Dennis,
My plan exactly. I just finished tying a set of PowerPro Maxcuatro 40 LB test lines using MS's knot with the double Lark's Head to secure the line clip. I did use the Knot Kneedle to set the end point and thread the loops through, for me it helped with the thin lines (0.10" dia). Once all was secured as Mikes method, I hooked the lines to a nearby fence section and gave a good pull and held. It felt pretty stretchy, I really though all was lost.
Then I decided to do the same test with my current 0.012" stainless cable. They also felt the same stretchiness which surprised me. My conclusion is they felt the same so the only way to see if there is any control issue is to fly them back-to-back. Tomorrow is going to be cool here in S FL around upper 50's (this use to be the KOI weekend and 4 out of 5 yrs it was cold and very windy) but low wind so should be a good week to test the lines and the impact on the battery amp usage.
Best, DennisT
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Tomorrow is going to be cool here in S FL around upper 50's (this use to be the KOI weekend and 4 out of 5 yrs it was cold and very windy) but low wind so should be a good week to test the lines and the impact on the battery amp usage.
Best, DennisT
I'll be sacrificing a lot of electrons next time that weather shows up here! Fair winds & tight lines...
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Yesterday we had a nice break in the weather. I needed a set of 64' lines for my new Pathfinder Twin which weighs in at a porky 68 ounces. Three sets were made: .018 stainless, .015 stainless, and .016 Spectra (Daiwa J-line 65#). I pull test new lines to 30# each while anchored to my backyard fence. Stretch including line sag after pretension to 5# is very close to the same for each or about 0.8%. Flight test were made with the same RPM, CG, and lead-out position. I measured lap times and noted the feel at the handle. I used the same handle for each test flight. There was less that 0.1 second variance in lap times, which were probably subject to error due to timing and piloting at the same time. It did appear that the .016 Spectra was slightly slower, but there were not enough flights to get repeatable results. As for pilot feel the results were easier to distinguish and as expected. The stainless lines were about the same with a slight edge going to the .018. The Spectra lines definitely had a rather "soft" feel and it was necessary to lead the corners more than with the stainless. I also checked battery consumption. There was little difference between flights and many more flights would be required to get any meaningful results. Not a very scientific test, but enough for me to prefer stainless lines at least for now. I didn't have any 100# Spectra to test, and I'm curious what others have experienced with 100# Spectra.
Fred
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Stretch including line sag after pretension to 5# is very close to the same for each or about 0.8%.
...
The Spectra lines definitely had a rather "soft" feel and it was necessary to lead the corners more than with the stainless.
Fred
Thanks for reporting the results, Fred. Overall, the conclusions line up with my measurements exactly: the 65# Spectra (exact brand doesn't seem to matter too much) is softer than 0.015" stainless and definitely way softer than 0.018" stainless.
The elongation measurements you reported above most likely lacked resolution: at 5 lb load, the difference between the lines would be so small that it is hard to detect the difference using a standard ruler, especially while maintaining constant tension on the line with another hand. That's exactly the reason why I apply 20# load to measure elongation: not because it reflects the actual in-flight loads, but because it is feasible to obtain decent measurement resolution (say, down to 1 mm or about 1/32").
For a 68 oz plane, you would need 100# Spectra, properly conditioned, and you still might give a slight edge to the 0.018" stainless, if my measurements are correct.
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Today I was able to do the back-to-back test flights of the 0.012" stainless steel cable lines against the PowerPro Maxcuatro 40LB test on my 34 oz E Ringmaster. Having made up the lines and pull tested found that both the 0.012" SS and the PP Max (0.010") felt about the same in stretch from the simple backyard test I figured the only way to see if there was a significant difference was to fly them both.
I flew the first flight on the 0.012" SS lines, they are 59' 6" the lap time for the ship is 4.7 sec.(56 mph). This gives a very solid feel and the estimated the pull is around 7.4 lbs.
Next flew the PPMax 0.010" lines, they measure 58' 10", lap time was 4.8 sec. (55 mph). The plane felt very solid and I didn't notice any real difference in the maneuver's, estimated pull was about 7 lbs.
When I checked the battery it told the story of increased amp use with the PPMax lines which was the opposite of what I was hoping for. I'm thinking that even though the PPMax are thinner then the SS lines and feel smooth to the touch that the slightly thicker SS lines are smoother to the air and less drag.
I have a set of FINS 40G, 45 LB test lines that are supposed to be smoother and thinner I will try these next time out and see if we save any amps.
Best, DennisT
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Yesterday we had a nice break in the weather. I needed a set of 64' lines for my new Pathfinder Twin which weighs in at a porky 68 ounces. Three sets were made: .018 stainless, .015 stainless, and .016 Spectra (Daiwa J-line 65#). I pull test new lines to 30# each while anchored to my backyard fence. Stretch including line sag after pretension to 5# is very close to the same for each or about 0.8%. Flight test were made with the same RPM, CG, and lead-out position. I measured lap times and noted the feel at the handle. I used the same handle for each test flight. There was less that 0.1 second variance in lap times, which were probably subject to error due to timing and piloting at the same time. It did appear that the .016 Spectra was slightly slower, but there were not enough flights to get repeatable results. As for pilot feel the results were easier to distinguish and as expected. The stainless lines were about the same with a slight edge going to the .018. The Spectra lines definitely had a rather "soft" feel and it was necessary to lead the corners more than with the stainless. I also checked battery consumption. There was little difference between flights and many more flights would be required to get any meaningful results. Not a very scientific test, but enough for me to prefer stainless lines at least for now. I didn't have any 100# Spectra to test, and I'm curious what others have experienced with 100# Spectra.
Fred
Hi Fred
THANKS for sharing your experience. I've read some positive reviews about the Daiwa J-Braid. Did you use the x4 (4 strands, .014") or the X8 (8 strands .016")?
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Dennis,
The Daiwa I used was 8 strand J-line which is supposed to be very round and have an especially smooth surface. It feels smoother than Power Pro although I have only seen one sample of each. I forgot to mention that the Spectra had a vibration mode that I could feel at the handle. The vibration might not be present at a different line length or environment. I am very curious about other people's first hand experience using Spectra lines for stunt.
Fred
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Thanks for reporting the results, Fred. Overall, the conclusions line up with my measurements exactly: the 65# Spectra (exact brand doesn't seem to matter too much) is softer than 0.015" stainless and definitely way softer than 0.018" stainless.
The elongation measurements you reported above most likely lacked resolution: at 5 lb load, the difference between the lines would be so small that it is hard to detect the difference using a standard ruler, especially while maintaining constant tension on the line with another hand. That's exactly the reason why I apply 20# load to measure elongation: not because it reflects the actual in-flight loads, but because it is feasible to obtain decent measurement resolution (say, down to 1 mm or about 1/32").
For a 68 oz plane, you would need 100# Spectra, properly conditioned, and you still might give a slight edge to the 0.018" stainless, if my measurements are correct.
Mike,
Good info. I selected 65# Spectra because its' load rating is close to .018 stainless. My elongation measurements started with one line pre-tensioned to 5# and then pulled to 30#. All three samples stretched to 6 inches plus or minus 1/2 inch. I think that much of the apparent stretch was due to absorption of line sag and not actual elongation of the lines. I assumed (perhaps incorrectly) that a similar condition exists in flight, and I was surprised at the soft feel of the Spectra lines. I need to re-test elongation without line sag, and find some 100# Spectra.
Fred
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Today in Napa, CA at 9:00am we started out at a nice brisk 39 degrees with little to no wind. It eventually warmed up to about 54 degrees by noon and a light breeze. A beautiful day to do some stunt flying! This was to be the first time flying with the new braided lines. I originally had a set of Power Pro Maxcuarto 80# x 60' made up that I was going to use. I realized that this was an overkill for my Circulas 25 that only weighs 39 oz., powered by a OS LA 25. I didn't think this would be a very good test.
It just happened that on Thursday my order of the white FINS 40G lines, both the 45# and 65# break strength, arrived in the mail. I ordered these lines directly for the FINS website at https://www.finsfishing.com/FINS40G-p/fns40g.htm (https://www.finsfishing.com/FINS40G-p/fns40g.htm). This is what the FINS website had to say about the 40G line:
"FINS 40G is the most unique braid on the market. 40G is a composite structure; comprised of an ultra high strength core which is very tightly overbraided with 8 ends of high tenacity gel-spun PE. Engineered to be extremely round and smooth and stay that way. Don’t let the mono-like feel trick you, this is a durable braid with the smallest diameter to strength ratio ever offered. FINS 40G is a real game changer!"
I only had time to make up a set of 65# x 60' lines that was used in my test today. After tying the ends, I measured each line before stretching and after stretching. Each line was stretched at 30# for 1-minute. Each line stretched an additional 2 1/4".
Today with the watchful eyes of Dave Fitzgerald and Brett Buck, I started with 2 flights using my .012 x 60' 7-strand stainless steel lines that I normally use. This was done to get a "fresh" feel for the steel lines. On the third flight I put on the FINS 40G 65# lines. For this flight the needle setting was too rich to do a pattern, but I could do some loops and inverted flight. I could see a nice bow in the lines at this slow speed. The white color on the lines makes them very easy to see both on the ground and in the air.
The 4th flight I had a good needle setting and flew a full pattern. I could tell that I had too much wing tip weight as the plane was hinging on the corners. But, other than that I couldn't tell any difference between the FINS lines and my steel lines. Control response was the same.
On the last flight I removed a 1/4 oz. of wing tip weight. The plane flew better as if I were using the steel lines. Again, I could not feel or see any difference between the two.
For my next test I will make up a set of the FINS 45# test lines to see if these react differently. So far so good. Until next time stay safe!
Dennis
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Today with the watchful eyes of Dave Fitzgerald and Brett Buck, I started with 2 flights using my .012 x 60' 7-strand stainless steel lines that I normally use. This was done to get a "fresh" feel for the steel lines. On the third flight I put on the FINS 40G 65# lines. For this flight the needle setting was too rich to do a pattern, but I could do some loops and inverted flight. I could see a nice bow in the lines at this slow speed. The white color on the lines makes them very easy to see both on the ground and in the air.
The 4th flight I had a good needle setting and flew a full pattern. I could tell that I had too much wing tip weight as the plane was hinging on the corners. But, other than that I couldn't tell any difference between the FINS lines and my steel lines. Control response was the same.
On the last flight I removed a 1/4 oz. of wing tip weight. The plane flew better as if I were using the steel lines. Again, I could not feel or see any difference between the two.
I have little to add, except that, to no one's surprise, the difference in trim from steel to synthetic was very dramatic, as you would expect from the weight difference. I am not sure that the airplane was dialed in enough, nor was there enough flights, to see if the trade-off between tab and tipweight and leadout position needed to be different (which it might be, just because of drag differences).
But I can tell everyone that from the outside, there was no indication that there was any difference in the compliance, if anything, it seemed more honest (again, just from observation from the outside - after watching *many, many* flight over the last 45 years, there are usually some indicators) on Spectra. Hard to say for sure because the temperature went from 41 to 58 over the course of the session.
It was a very well-designed first test, certainly showed no indication of any problems or issues of concern with synthetic lines.
Brett
p.s. Sort of on-topic - a whole bunch of people have emailed or texted thanking me for "getting Spectra lines in the rules". That's very flattering, but, that really wasn't my motive nor was the rule change particularly my idea. The rules themselves had irritated a lot of people for a pretty long time, just because of the fact that the line diameters fell right in the middle of competitive stunt planes, and never made much sense. This dates back long before the 10G pull test, it made even less sense when it was based on displacement. So a wimpy ST46 pulled 45 lbs (which was frequently more than 15Gs) and required .018s, a 40FSR could easily fly 70+ ounce airplanes, pulled 40 lbs/9gs and could use .015 stranded or **.012 solids**.
Any number of people recognized long ago that, in particular, the line diameters made absolutely no sense. I could have legally flown with .015 lead solder for lines - except that it wouldn't pass the pull test. This also eliminated or made pointless many other things that are likely to be a lot better/safer/more margin/more durable like Spectra, the Ukrainian or British carbon lines that would pass the pull test with abundant margin. But no one ever submitted a proposal to that effect, so, since while I have plenty of time for computers between my every-other-month flying and building sessions, and after the previous failed Spectra proposal, I went for the whole hog instead, and the CB agreed, so here we are.
I guarantee someone, somewhere, will try to see if they can get away with 10 lb Spiderwire, and crash in the process, but people used to do that back in the day before there were any rules, too. You won't likely be doing it at a contest because the pull test will weed that sort of thing out.
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DennisN,
Good information, it would be interesting to note the lap times on the different lines to see if the 40G's are less/more/same drag as the stainless. I have a set of 45 LB 40G to test on my 34oz ship and will see how they compare to the Power Pro Maxcuatro 40 LB test (0.010") lines that I flew yesterday. For me the 0.012" stainless cables were less drag/load on the ship the the PPM's. The ship was ~1mph slower for same pitch/rpm and had higher amp usage.
Best, DennisT
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Today with the watchful eyes of Dave Fitzgerald and Brett Buck, ...
Dennis
No Pressure! NO PRESSURE!!!
All seriousness aside, thanks for sharing your results. I agree that the unique structure of the FINS 40G makes it something to look into.
Thank you also, Dennis T & Fred C for sharing your results from the weekend. We were in the low twenties all weekend, I am jealous of "you guys that flys" this time of year...
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DennisN,
Good information, it would be interesting to note the lap times on the different lines to see if the 40G's are less/more/same drag as the stainless. I have a set of 45 LB 40G to test on my 34oz ship and will see how they compare to the Power Pro Maxcuatro 40 LB test (0.010") lines that I flew yesterday. For me the 0.012" stainless cables were less drag/load on the ship the the PPM's. The ship was ~1mph slower for same pitch/rpm and had higher amp usage.
Best, DennisT
. Dennis Just a FYI last week I flew my Sky Ray with 80 lb lines and found to much drag, so today I flew same plane with 30lb.Power pro. and it was great just like the .012 stainless that I've been using, did about 20loops and didn't have any control problems, I also pull test them at20lb and seams fine. y1 #^
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We were in the low twenties all weekend, I am jealous of "you guys that flys" this time of year...
Well at least there is one good thing about California!
Dennis
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. Dennis Just a FYI last week I flew my Sky Ray with 80 lb lines and found to much drag
Yeah, I was pretty sure the 80# Maxcuatro would be too much for my Circulas 25. I'm glad you found out for me. #^
Dennis
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Well at least there is one good thing about California!
I went to take some TVs to the recycling place down near Alviso - and it was closed due to a tsunami advisory!
Brett
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I went to take some TVs to the recycling place down near Alviso - and it was closed due to a tsunami advisory!
Brett
Now that's funny! LL~ LL~ LL~
Dennis
BTW, I did notice that there was also a tsunami advisory for Napa too.
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. Dennis Just a FYI last week I flew my Sky Ray with 80 lb lines and found to much drag, so today I flew same plane with 30lb.Power pro. and it was great just like the .012 stainless that I've been using, did about 20loops and didn't have any control problems, I also pull test them at20lb and seams fine. y1 #^
Larry - thanks for sharing your results.
According to the chart PP 80# is .017", PP 30# is .011". I am planning to use PP Super Slick 8 40# (.012) in place of .012' cables, starting with the Barnstormer & Ringmaster. I originally bought this line for the Brodak Gladiator electric combat wings which are about the same size as a 1/2A combat wing. Still got lots of 40# line to use up.
Most loops I have heard of so far is 41....
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Now that's funny! LL~ LL~ LL~
I have to say, I didn't see that one coming!
BTW, I did notice that there was also a tsunami advisory for Napa too.
Oh, my GOD, the flying site is about 25 feet from the river!
For those not familiar with the area, if it really did say that, then it was a bit exaggerated. Napa is probably about 30-40 miles from the coast, and it's not going to do anything to the river. Unless the moon decides to crash into the Pacific, I think it's pretty safe from tsunamis. There are some pretty low-lying areas between here and there, but not enough to have any effect from a 4-6 foot high tsunami. Having to strain itself through the Golden Gate Strait, then the Sacramento delta, means even the tides are greatly attenuated. I sure hope so, my place of work is about 200 yards from the bay, and about 18" above sea level.
The places that had minor flooding and damage were all right on the coast, like Santa Cruz, with the coast facing the west southwest, which is the direction it came from, and, the same direction as the onshore breeze.
Brett
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Our field at Alameda CA is about 50' from the shore, and about 3 miles in a straight line to the open Pacific through the Golden Gate. A 3 foot surcharge in sea level would definitely put us under water. Luckily we stayed high and dry.
I watched Larry put up a whole lot of consecutive loops yesterday with his Skyray on the thinner Spectra lines and saw nothing unusual or alarming. From this non-scientific evaluation it looks like the lines are fine for smaller models. So far none of us has tried them on a full-size stunter.
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Our field at Alameda CA is about 50' from the shore, and about 3 miles in a straight line to the open Pacific through the Golden Gate. A 3 foot surcharge in sea level would definitely put us under water. Luckily we stayed high and dry.
Aimed the wrong way, though - or the right way, depending on the your perspective! The excuse in Alviso was that the shore was aimed right at the long axis of the bay, so, if a wave did come in, it would hit square on. Of course, nothing of the sort actually happened, but guys at the junkyard got the day off to watch football.
Brett
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Right, we weren't so concerned about direct wave impact as a generalized surge in sea level. We come perilously close whenever there is a king tide several times a year.
I am going to try Larry's Spectra lines on my own .25 size model and see what I think. For the time being I intend to stick with stainless or brass plated steel for my primary model. But who knows where this will lead? It appears knots and line connectors are the issue rather than the lines per se with Spectra type lines.
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Right, we weren't so concerned about direct wave impact as a generalized surge in sea level. We come perilously close whenever there is a king tide several times a year.
I am going to try Larry's Spectra lines on my own .25 size model and see what I think. For the time being I intend to stick with stainless or brass plated steel for my primary model. But who knows where this will lead? It appears knots and line connectors are the issue rather than the lines per se with Spectra type lines.
There should be no issues with Spectra and line connectors. I've easily used heavy duty equal sized slide clips of appropriate pull test. We've also run the bent music wire clips(with the closure at one end) or similar Sullivan line clips.. The double loop modified Surgeon's knot with half inch or so loops works fine. Another possibility if there is easy bellcrank access is to but brass buttons on the bellcrank- simply a flat head about 0.040 thick with a .040 dia. post(for the lines) and a smaller extended ~0.020 x ~0.18 long post Push the small diameter through the long arms of the bellcrank and peen the slightly protruding pin just like a rivet. It will be locked in solidly. The line loop can only come off intentionally, or possibly some kind of freak accident that twisted the plane enough to allow the line loop to slip off- maybe sometime when the sun doesn't rise! Unlike designing and scratchbuilding a new plane which takes a lot of learning and then a lot of time.
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I chatted with Nikki at Brodak yesterday. It is her intention to stock Power Pro 65# x 60' as a trial - to see if there is any interest in it. If so she will be open to stocking other weights & lengths comparable to their SS cables.
If you have been "sitting on the fence" about trying Spectra this would be a good way to try without investing in a lot of line. The 65# size is a pretty good substitute for .015" SS cables, It is lighter than the cables but is nominally larger at .016 instead of .015". This is the size I started my tests with; no issues with stretch, and the slipperiness should come on through.
Not sure exactly when the new lines will be available, but keep an eye on the Brodak site, and I'll try to update here when it is in stock.
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Finally, some flyable weather. I took the S1 Electric Ringmaster out and tested the FINS 40G, 45LB Test (0.009" diameter) lines. Short answer is we have a winner!!
The last test was the 0.012" stainless steel cabel lines vs. PowerPro Maxcuatro 40 LB Test, 0.010" diameter lines. For the SS cable lap time was 4.7; PPMax lap time was 4.8 sec. On the PPMax the plane felt very solid and I didn't notice any real difference in the maneuver's, estimated pull was about 7 lbs. At the end of the test the battery voltage on SS Cable was 18.4V the PPMax was 17.6V, just above cutoff.
Today's test was with the FINS 40G lines, prepared like the PPMax double surgeons knot (per the posted video) using the Larks Head to secure the line clip. Pull tested the lines and all was good to go. Switch on - off we go. Ship felt really good and solid, speed felt right, control response was solid, no sponginess or delay, even when I purposely banged a hard corner just to see. Lap time was 4.69 sec right on top of the lap time for the 0.012" stainless steel braided cable (4.7 sec). After the flight comes the real data to see if there is any benefit. Pack is TP 5S - 1350mah, end voltage 18.5V, mah put back on recharge 1093. This left 257 mah in the pack 19%. That is 5% more reserve that with the 0.012" SS cable so by my tests I have achieved my gold of reducing the amp draw and allows good battery life with this setup.
Best, DennisT
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Flew today flew the S1 and got to unintentionally test the shock strength of the the FINS 40G, 45LB Test lines with the double Surgeons knot and double Larks Head clip attachment. Since the S1 Ringmaster seemed to be good on flight time and reasonably solid on the lines started to take it through the OTS pattern. All good through the horizontal eights. The vertical eight was where this ship had trouble as it would not turn tight enough loops to do the maneuver. Since the rebuild with the sharp leading edge and sealed hinge line there is no problem with the size of the loops. So, into the vertical we go and does the first one pretty good, I go up the second and for some reason I opened up the top and the ship got off wind a bit up wind. This then cause it to float in on the lines but fortunately I was able to back up a bit and BAM it hits the end of the lines, I got it around but inverted. I realized where it was and leveled it off but then tried to get it back over, (rookie mistake flipped it to soon up wind) and again it drifted loose, back I peddle and BAM again it hits the lines, I get it level and check the neutral is still neutral, all good.
So, the Spectra lines held fine, knots did not slip, lines did not change length all is good.
Best, DennisT
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While sorting through my brothers modeling stuff, I found his stash of SS cable lines. I have already thrown my out, but in a fit of inspiration I weighed his and compared them to some of the Spectra lines I have made up. Nothing fancy, just weighed the lines on the regular 3" reels, then subtracted out the weight of the empty reel. To make it easier to compare I then scaled the net with slightly up or down so represent a standardized 65' line set. All lines were made up ready to use. The cable sall have wire wrapped ends, the Spectra's all tied with the Modified Surgeon's knot per Mike Stinson's video. The results:
.018" x 65' 7 strand SS Cables: 45 grams
.018" x 65' 19 Strand SS Cables: 39 grams
.021" x 66' SS Cables: 59 grams
.015" x 65' SS Cables: 30 grams
Power Pro, 100# x 65': 9 grams
Maxcuatro 80# x 65': 5 grams
Suffix 832 80# x 65': 5 grams
Suffix 832 65# x 65': 5 grams
Power Pro Super Slick 8 40# 2 grams (!!!)
In the Spectra thread on the Combat forum it was reported that the 100# Power Pro was 1/5 the weight of .018" cables - I matched/confirmed that for that size of line.
Bottom line is that for most airplanes, line weight can become negligible, adjusting tip weight by even 1/4 oz will likely be too much! I am going to build my new airplanes with just enough weight to balance it side to side then determine tip weight by flying, starting at about 1/4 oz. The new weight boxes we use will likely let us adjust weight a couple BB's at a time. I'm also thinking that wing asymmetry may be obsolete...
One airplane I can hardly wait to try is my Stuka Stunt which up to now I flew on .015" x 58' lines, that weighed about 26 grams. I plan on using FINS 40G 45# x 58' which is somewhat smaller/lighter than the 40# Power Pro shown above. It has 1" longer inboard wing. Expecting to add inboard tip weight, and/or a tab on the outboard flap to control hinging.
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Has anyone ever done a test of solid vs. cable to see which has more drag? It would be interesting from the side point that in the past the commonly held belief was that the thinner solids would be less drag than the braded cable, also they stretched less. I never heard of anyone doing a real test. I think with IC it might not be too easy to tell maybe the one with more drag would require a more rearward leadout position?
When doing the side-by-side Spectra test of the 0.012" braided SS cable vs. the 0.011 Spectra PowerPro Maxcuatro on my electric Ringmaster I found the SS Cable had less drag. What I am wondering is if the smooth round Spectra is actually more drag because it is so smooth or is there a surface roughness that can't be felt that causes the drag difference? It goes back to the dimples on a golf ball idea, maybe super smooth is not what we need to look for, maybe something that is a smooth braid (like the SS cable braid) would have less drag?
What I have been doing so far was to look for the smoothest and thinnest Spectra line which so far has been the FINS 40G brand line. This line is a 9 braid line and very round, thin, smooth and high cost then some of the simpler 4 or 5 braid lines, but is if less air drag? Could be that some cheaper lines that are more of a braid feel would be less drag? The trade-off might be that the 40G for the same #Test will be thinner and that even with the more draggy smoothness would still be less drag. If anyone tried this type of test please let us know even if it was solid steel vs. SS cable.
Best, DennisT
Best, DennisT
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I am down to my last set of Ukranian lines. I pray that I will be able to get more someday but I have to make contingency plans. I prefer Spectra to going back to steel so I grabbed a roll of 65# today on impulse. I will test them on a 62oz plane on 65' lines (clip to clip). My question is simple - is this the right weight line?
Ken
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When Slow Rat went from braided to solids back in the 80's sometime, the results were surprising. We thought that the solids would be slower, draggier. We thought the cable nature of the stranded lines would act as a boundary layer trip, like dimples on a golf ball. The perfectly cylindrical solid lines would have a more turbulent wake and produce more drag. Well, the solids went faster.
Why? ... well after a bit of measurements we found that the average set of steel braided 018's were really .0188, almost 4 percent bigger. . The solids measurement tended to be right on or slightly less.
This doesn't answer your question other than you should be sure to actually measure and not take the word of the package.
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Ken,
The 65LB Test should be fine, look at the video for tying the knots, it works.
You didn't mention the brand, all Spectra lines are good for the rated test, but some brands are thinner diameter and stronger at that. Of the ones I've flow I find the FINS 40G line is the thinnest with least drag compared to others of the same LB Test.
Best, DennisT
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Ken,
The 65LB Test should be fine, look at the video for tying the knots, it works.
You didn't mention the brand, all Spectra lines are good for the rated test, but some brands are thinner diameter and stronger at that. Of the ones I've flow I find the FINS 40G line is the thinnest with least drag compared to others of the same LB Test.
Best, DennisT
Thanks Dennis, I ordered some, we will see how it goes. Lighter, cheaper, stronger and available wins out again.
Ken
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put a set of 60 lb spectra on my veco 35 powered WOW and felt that they had too much drag.felt lite on the lines .normally use .015 braided
Dave Platt talks about flying 15 diesel stunters on .008 and .010 solid lines back in the day in England
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Bob,
Depending on the Brand, Spectra 60 LB Test is not all the same. I flew my E Ringmaster on 0.012 braided cable then flew on PowerPro Maxcuatro 40LB test (0.010" diameter stated). Although the ship flew fine there was about 3% more battery drain with the PP Max lines. I then flew on a set of FINS 40G 45 LB Test (0.009" diameter stated) lines and it was 4% less battery drain, then the SS 0.012 cable lines. I have been using the 45LB test FINS for all the ships that would have used 0.012 cable.
Use the double surgeons knot with the bit as shown in the posted video, it doesn't reduce the line strength significantly for our 10x pull test.
Also remember when going from SS Cables to Spectra you need to adjust the tip weight and leadout sweep position for the lighter thinner Spectra lines.
Best, DennisT
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I recently competed in the VSC and in the process greatly expanded on my still sparse experience with Spectra lines, thought I share that here.
I think Wes & I were the only ones at VSC using Spectra, but we answered a LOT of questions about them, mostly "how to tie them?" which of course is shown in Mike Stinson's video on Page 1 of this post. I took several sets of lines along & got even more attention for the BOX I carried them in! Shown here is the Plano Line Spool box designed to carry & dispense up to 6 spools of fishing line. However using our normal 3" reels I was able to get 10 reels in there! Note that this box will work with SS cables too, just so they are on a 3" reel. here's a link, and I have also seen it on Amazon:
https://www.tackledirect.com/plano-1084-line-spool-box.html
Since the lines were all new and neither of us had flown since last fall the first order of business was to get a handle setting and start practicing. After some warm-up flights on the Ringmaster, I used FINS XS 50# x 60' (.014") on my Joker OTS that weighs 35oz. I used a Reyco cable handle (Hot Rock clone) so handle adjustment was a question of tweaking the setting over a couple flights. My flying buddy Wesley Dick used the same line material (at 63') on his 46oz Ares. Wes uses a Brodak "Rock Crusher" handle and got the setting right first try. Both airplanes are electric and had only ever flown on .015 cables before. In each case we removed 1/4oz tip weight (all we could pull), but needed to remove more. These lines are mixed colors, orange & blue, (blue side UP) and one or the other of the lines were pretty much always visible on the ground. We both liked the Spectra, but we have additional opportunities, especially the Joker should be able to fly on smaller dia line. After the meet I gave my lines to another flyer to try, looking forward to him sharing his experience here.
I flew my 47oz Jack Sheeks "Swinger" Classic using "Pink Camo" Spiderwire 65# x63' (.015"), a good line but not a good match for this airplane. Frankly, the line looks best on the reel! The line was pretty much invisible everywhere except on the blacktop circles where the non-black sections of line were visible.
I still have my original set of Suffix 832 65# x 60' (.016") on the Ringmaster. Those lines will be replaced next time out with PowerPro Slick 8 40# x 60' (.012"). Should have done that before we left, but the Ringer was all set to fly and it was our warm-up airplane before touching the "official" birds. It did its job, only next time it will be ready to do it better.
I started using #3 size welded rings in the end loops, tied using "Lenny Loops" (larkshead knots). The goal is durability to attach & remove line clips with absolutely no wear on the loops. One downside is the rings that I used are small enough to wiggle between the ends of a homemade scissors style clip bent on a clip bender, a little fatter ring would be nice. NOTE: before I got the welded wire rings i found some others described as solid rings. These were essentially very high quality washers; cleanly stamped, de-burred and finished. However they were flat with a small corner radius that I thought could potentially damage the line. The rings I'm using are bent from round wire and welded - no corners. I just ordered some slightly larger rings for the next batch of lines.
https://www.tackledirect.com/quick-rig-stainless-steel-welded-rings-3.html
https://www.tackledirect.com/spro-swlslr-035-12-power-welded-ring.html
The "proof" in any new technology is when you start to "campaign" with it. For us, Spectra lines passed the test at VSC, being easy to handle and performing as needed. Even survived a person walking through them! I just need to keep improving my line making chops...
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Just a suggestion guys, Berkeley Whiplash is very thin ! 65lb is 0.2mm equates to 0.00787!
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Just a suggestion guys, Berkeley Whiplash is very thin ! 65lb is 0.2mm equates to 0.00787!
Have you used this much?
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Just a suggestion guys, Berkeley Whiplash is very thin ! 65lb is 0.2mm equates to 0.00787!
Hello Cory
Searched online and could not find anything on Berkley Whiplash. Do you have any info? More important, do you have any experience with this line you can share?
No question there are some super-thin lines with adequate rated strength. My concern is does the small diameter compromise on stretchiness?
I am going to simplify my choices (and possibly be conservative doing it) by using Maxcuatro 80# (.016") in where I used to use .018" cable, Maxcuatro 50# (.012") where I used to use .015" cable, and FINS 40g 45# (.009") were I could have used .012" cable. However, I only used .012" cable on one airplane because those lines were just too fragile. I have a bunch of OTS & Ringmaster class airplanes, all under 36oz that I used to fly on .015" cable that will be switched to the .009" Spectra, THAT will be a big change for the better for those birds!
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I have never used Berkeley Whiplash for control line! My only experience is with deep sea fishing 500m deep using electric reels!
Reason being it has less drag when currents were an issue! It is super strong ,It has zero stretch and good knot strength. I would use a binimy double and attached to clips ,swivel with dog paw knot as we call it ,very simple . The only issue is ,it’s expensive and if you lost a lot of meters , I’m interested to give it a try on one of my models tho ! I’m trying to load a pic but file is too large,
Found some on Amazon and EBay
Cory,
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I have a real reservation in using lines that are super thin. It may be irrational but aren't thinner lines more subject to catastrophic failure for small imperfections/damage that may go unnoticed or is the risk the same as it is for thicker lines. I have become so used to the feel of a kink or rust spot when running out steel lines that I don't think I would spot an imperfection in fishing line.
Ken
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I was always shown to tie spectra as doubled , to a swivel or ring,
https://youtu.be/FXTZxfbc3-Y
https://youtu.be/DDE9uTIA9Sw
This is probably the method I will try as I have never had this fail in my experience.
So you would tie loop knot first and then the swivel knot , it would look similar to Dennis pic earlier
Cory
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I've used Berkley Whiplash 65lb without any problems, I like it, however I've little experience of anything different/ better.
Using a micrometer, the thickness of the Berkley Whiplash does indeed measure around .2 mm (.008"), however you are squashing the braid flat. Without a better way of measuring the diameter, that does not squash the braid, my gut feeling is that air will see a greater diameter than that quoted on the packet?
Steve
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Cory, what does he do with the loose end? ???
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Cory, what does he do with the loose end? ???
Hi John,
Not exactly sure what loose end you mean .
But the second YT video is a little confusing I guess, it should be a finished loop !
If you’re talking about the small tail after the loop , you can burn it , it’s not as neat as nylon , but keeps it tidy
Cory
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The knot looks very neat but I think AMA recommends (per Mike Stinson video) making a "bit" loop then do the knot. The "bit" in essences is a double loop then do the knot. I like Mike's approach as it is easy to get the lines the same length and it doesn't significantly reduce the strength of the line.
Best, DennisT
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I just made up a handle with Spectra line.
(https://i.postimg.cc/xC67NxXb/20220330-191324.jpg) (https://postimages.org/)
I used 15# yellow for the down line and 15# green for the up line.
Mark
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Cool, Mark.
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When I was 11 we flew on braded fishing line and carpet thread that was half the distance between the trees in the back yard long. That handle reminds me how far we have come. I had a yellow one! LL~
ken
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Some where in the stash I still have the fibre handle that came with some of the 1/2A kits with dacron lines. Just roll the lines on to the handle. Adjustments was loops around the handle. My brother Bob had both of the Thimble Drome handles. Dacron line on small handle and .018 on the bigger handle. But what did we know back then and the swivel clip hjow many flights were made using those. It wasn't until I started to fly competition that we learned they were not safe. Guess we were lucky as we never had an accident.
Been using sewing thread to practice the first loop for lines easy as pie once you do it a couple of times. Don't know howmuch pull I was putting on the thread but I could not get thread or loop to break. Will find out when I go to the Power Pro line. H^^
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Just got my order of Fins 40G 65#. Looks to be about the same size as PowerPro 65# but much smoother. My big decision is which connector. Direct to the clip, loop on the end or tied to a ring. I think I like a double loop on the connector.
Ken
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Just got my order of Fins 40G 65#. Looks to be about the same size as PowerPro 65# but much smoother. My big decision is which connector. Direct to the clip, loop on the end or tied to a ring. I think I like a double loop on the connector.
Ken
Use a Larks Head knot to attach it onto the line clip.
Aka, The "Lenny Loop"
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Ken,
I would use the end knot described by Mike Stinson video. This is a double surgeons knot with a "bit" as recommended by AMA. Then use the Larks head to loop onto the line clip (I use the scissor type clip). Since you have the FINS 40G 65# and the PowerPro Max 65# line it would be interesting to see which line is less drag. In my experience the FINS 40G will be thinner and less drag than the PowerPro's. Let us know.
Best, DennisT
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I think Wes & I were the only ones at VSC using Spectra,
What the h-ll is taking everyone so long!!??
As a Ringmaster/Buster/Twister, non competitive kind of flyer, Spectra got me flying the pattern after 70 years of flying control line. (My fleet of hand-me-down stunters are all overweight and beyond proper trim). I understand that most of you are professional engineers and scientists who bring the protocols of your professions to the discipline of C/L Aerobatics. Your input, research and improvements to the sport are breathtaking. But for the endless analysis, testing, agony over which knots, follow the leaders, crunching of numbers, and never ending discussions are getting a bit tiring. Admittedly, I'm not campaigning a front row wonder. But for us grunts, the news that Spectra was light weight, non kinking, visible, strong as or stronger than steel made me an instant convert. Plus, the Combat guys have been USING THEM FOR YEARS!
Ara
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I need some spare lines for this season. Looks like okie air wants $40 a set for anything over 60'. So, how are spectra holding up? I'd hate to destroy a plane trying to save a buck. How does the flex compare with 7 strand? You guys make it sound like a no brainer, any final thoughts?
Okay, follow up. The FINS sounds pretty good. What are we thinking for a 40 size plane vs a 60 size. I e. .015 and .018 equivalents.
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Dave,
I think the FINS 40G will fit your needs. Use the knots shown in the video. My way of determining what LB Test to use, I take the weight of the model in LBs, times two times 10 then get the nearest LB Test line.
Best, DennisT
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Dave,
I think the FINS 40G will fit your needs. Use the knots shown in the video. My way of determining what LB Test to use, I take the weight of the model in LBs, times two then get the nearest LB Test line.
Best, DennisT
So I should be getting 8lb test for my 64oz plane? I think you quoted your formula wrong.
Ken
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Ken,
Sorry, I forgot to add the multiply by 10, corrected post.
Best, DennisT
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I need some spare lines for this season. Looks like okie air wants $40 a set for anything over 60'. So, how are spectra holding up? I'd hate to destroy a plane trying to save a buck. How does the flex compare with 7 strand? You guys make it sound like a no brainer, any final thoughts?
Okay, follow up. The FINS sounds pretty good. What are we thinking for a 40 size plane vs a 60 size. I e. .015 and .018 equivalents.
If you want to stay with 7 strand stainless you can buy 1000' of .015" or .018" for $40.00 here:
https://mbsmodelsupply.com/Catalog.pdf
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I need some spare lines for this season. Looks like okie air wants $40 a set for anything over 60'. So, how are spectra holding up? I'd hate to destroy a plane trying to save a buck. How does the flex compare with 7 strand? You guys make it sound like a no brainer, any final thoughts?
Okay, follow up. The FINS sounds pretty good. What are we thinking for a 40 size plane vs a 60 size. I e. .015 and .018 equivalents.
Hi Dave,
If you use a knot that can't slip, the rulebook shown knot is just fine. Other than that, they will be good for years. I'm using the very first set of lines I made up years ago. They still can handle a full 45lb F2D combat line test.
BTW, finding that out made a modest discovery. I pull tested at the NATS where they us a calibrated pull double-checked by a couple of spring scales. The F2D limit is about 4in. Both sets, the imported, brass plated 4 strand and the common stainless, .018 lines, stretched EXACTLY the same length,- about 1/4 in. less than the limit. Surprised the heck out of me!
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If you want to stay with 7 strand stainless you can buy 1000' of .015" or .018" for $40.00 here:
https://mbsmodelsupply.com/Catalog.pdf
Hey, that's quite a bit cheaper than fins 40g. So, for a bargain, get steel wires. For weight and durability, get spectra.
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Hey, that's quite a bit cheaper than fins 40g. So, for a bargain, get steel wires. For weight and durability, get spectra.
Which F2B world champion won with Spectra?
Which Nats Open champion won with spectra?
Which MACA # 1 in Combat did it with spectra?
Which F2D world champion did it with spectra?
At one or two sets of lines per year for Stunt; How much did you save?
Durability? A set of steel lines will last you a minimum of a year flying stunt. At the MBS price above that's between $5-$6
They are lighter. Do you think that 1/4-3/4 oz. you get to remove from your 50-65 oz. airplane will make much difference in the performance?
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Don,
If you don't try them you will not know if that 1/4 - 3/4oz off your ship will be a benefit. No one is trying to outlaw steel lines, use what makes you happy and keeps you flying. The Spectra lines are just a new option for Stunt, they allow using thinner lines for the same strength (based on FINS 40G lines) which gives less drag. For electric, this means drawing less amps. For IC you would likely be able to tune for less fuel. In both cases it further reduces weight (less fuel or smaller battery pack). Cost wise and durability wise they are 1/3 the cost of current day stainless steel and according to the combat guys last several seasons. Try them you might like them.
Best, DennisT
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Don,
If you don't try them you will not know if that 1/4 - 3/4oz off your ship will be a benefit. No one is trying to outlaw steel lines, use what makes you happy and keeps you flying. The Spectra lines are just a new option for Stunt, they allow using thinner lines for the same strength (based on FINS 40G lines) which gives less drag. For electric, this means drawing less amps. For IC you would likely be able to tune for less fuel. In both cases it further reduces weight (less fuel or smaller battery pack). Cost wise and durability wise they are 1/3 the cost of current day stainless steel and according to the combat guys last several seasons. Try them you might like them.
Best, DennisT
"Cost wise and durability wise they are 1/3 the cost of current day stainless steel and according to the combat guys last several seasons. Try them you might like them."
Where do you get FINS 40G in appropriate strength for less than $40/1000ft.?
What "combat guys" are you talking about? We fly in most of the major competitions and rarely, if ever, see it used in competition. As for lasting "several seasons" they're obviously not actually flying many combat matches or they're stretching the truth.
If used in combat the rules still require the diameter to be .018" for "slow" or "fast"
I have tried them. I would describe them as a labor intensive solution to a problem that doesn't exist. I can make a set of stainless lines from a bulk reel in under 10 minutes that are perfectly equal in length.
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If used in combat the rules still require the diameter to be .018" for "slow" or "fast"
I have tried them. I would describe them as a labor intensive solution to a problem that doesn't exist. I can make a set of stainless lines from a bulk reel in under 10 minutes that are perfectly equal in length.
I am curious why the Combat rules only recognize diameter when "Spectra" is considerably stronger at the same diameter. But, the rules are the rules and the benefit to us PA guys is not the strength, that is a given. It is the stretch and drag. Stretch has been tested to be the same or less and size is smaller. I don't find them much better than the now legal smaller diameter "Ukranian" lines which I will continue to use until they are no more.
My family owned a fishing tackle company when I was in my 20's. With practice, *a lot* of practice, you can tie knots much faster than you can wrap lines, especially if you are using heat shrink on metal, and always forget to put it on the line before you wrap it. It won't be long before some of our more innovative types come up with a wrapping tool for Spectra. Maybe they have already.
Ken
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I am curious why the Combat rules only recognize diameter when "Spectra" is considerably stronger at the same diameter. But, the rules are the rules and the benefit to us PA guys is not the strength, that is a given. It is the stretch and drag. Stretch has been tested to be the same or less and size is smaller. I don't find them much better than the now legal smaller diameter "Ukranian" lines which I will continue to use until they are no more.
Ken
Ken
The concern was avoiding a speed advantage for the Spectra equipped birds versus the steel. Specing 100# Power Pro based on its size and not its strength took care of that. In the 14(?) or so years since Spectra has been used in Combat there are now a LOT of different suppliers of Spectra line with different construction, size and strength advantages versus original Power Pro.
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Alert: This is not a techno-talk reply.
I know the dissemination of technical info is the lifeblood of this forum. But, because of Spectra lines, I'm having such an adventure with a good 'ole low tech CG Buster/Fox 35 that I had to put it on here.
This was going to be the summer of flying Dave Slagle's Bippi RC biplane after struggling for two years with its Saito 30 gas engine. I'd love to tell you all about it, but, suffice it to say there's a topic on RC Groups that goes back to 2009(!!) dedicated to problems with this engine. So, problem now solved (replaced the carb), weather, home repairs, weather, grandson's broken elbow, weather etc. got in the way.
Also, (taking more of my time), we've been instructing full scale aviation students from the University of Maine on flying RC and gave a C/L demo with the Buster. To assure all went well, I used Spectra for the first time on this model and the difference in performance was astounding. I flew the Old Time Pattern with AMA 'eights' and square maneuvers thrown in with no problem.
I did tweak the stock Buster with tank plumbing, needle valve replacement, tank position, and sealed hinge line. I'm using yellow 65# test x 62'9" lines. It's so reliable and steady that it's turned this year into the summer of flying the pattern with a Carl Goldberg Buster, all because of Spectra.
Ara
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Hello Ara
Good to hear your positive experience with Spectra line, our favorite for 15-25 size combat and mid size stunters is 65 lb too.
I wonder if Spectra will find its way into international F2B competitions in time ?
Regards Gerald
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Thx for all the detailed info on Spectra lines. I fly mostly sport and a bit of stunt as I work on the 'pattern'. I really like the Spectra lines. I have flown 40 size models with 65# test lines. One extra benefit. Since the lines are lighter (compared to SS) one can normally get away w/ less wing tip weight. So, an overall lighter model which is a good thing!
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What lines would you recommend for a 20/21 oz model? Any brands I can buy at Walmart, or stuff I need to order? Only if it's lighter or thinner than .12*7, which I already have.
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What lines would you recommend for a 20/21 oz model? Any brands I can buy at Walmart, or stuff I need to order? Only if it's lighter or thinner than .12*7, which I already have.
Hi David
Lessee, 20 oz = 1.25 lbs so a 10G pull test would be about 13 lbs. I did a quick search on Walmart and found they list PowerPro - which is a pretty good go-to choice. For me I would get the 20# line (thus 40# theoretical pull test capability) which is .009" diameter. BTW, if you simply wanted to break even on line diameter vs .012" SS cable you could go as high as 40# line! In any case weight is line weight is negligiblle.
WalMart lists PP 20# at $12.49 for 150 yards. You can probably beat that price with an off-brand. Of course, line price improves for larger spools.
If no luck at Walmart try a local tackle shop. Of course, Amazoom is also a pretty good source.
If you cannot find original PowerPro, other brands I have had good luck with: PowerPro Slick 8, Spiderwire, FINS WindTamer, & Suffix 832
Things to look for: Spectra, Dyneema, or IZANAS fiber
Get a light color: white, yellow, bright green, blue, orange, or pink!
Colors to avoid - Dark Green line absolutely disappears in the grass or on blacktop. Dark brown not much better....
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The AMA has a simple chart:
Model Weight oz Engine Spectra Rating lb (minimum)
24 .09 20
40 .25 40
64 .40 60
75 .75 100
I use Spectra 65# test for my .40 size models. (I don't believe you can get 60# test. Just use next size up)
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Thanks for this information. I have been using FINS 40G Spectra line that follows your chart very closely. I use the knots as shown in the video on this thread, works great and can get the lines very close to same length, then do final trim with handle cable.
Best, DennisT
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My planes typically come out in the 65oz+- range. Power is 35xx electric. Pull test is roughly 40lb. Why would I want to use anything more than 65lb in "Spectra" for this size plane? Even if it is a pig at 75oz the pull test is only 47lbs for 2 lines. Everybody seems to be recommending 80lb+. Is it the stretch? We don't seem to have a problem trusting .018 steel which is around 50lb or less.
Ken
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Ken, 80# test Spectra is overkill for a 65 oz model. 65# is all you need if you want to follow the AMA guideline. One can always go w/ more strength, but just increases the safety factor.
I have a Vector 40 that weighs 64 oz. I fly it w/ 65# test Spectra lines.
And one other thing. There are 2 lines out to the model. So, each line sees 1/2 the load. If you do a model pull test at 40# each line is only seeing 20 lbs. Two 65# test Spectra lines totals 130 pounds. It would take a total load of 130 lbs to snap those lines. So, a 40 lb pull test still has a 3.25 safety factor over the ultimate strength of the lines.
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While I do not disagree with any of the comments regarding breaking strain I do remember when I was a callow youth having a line failure on a Fox 36x combat special powered Flight Streak. It did about 12 very tight loops before the remaining line said "Enough" and it finally ran out of airspace about 400 yds away. I always aim for a breaking strain at least equal to the pull test for each line.
I've just completed a small fun model for a club fun event. (Mercury Viper, foam board facsimile). 12oz, Cheap Chinese outrunner, 1300mah Lipo 10A Castle ESC. Does the OTS schedule with ease and has capacity to do it all again if necessary. I use Spectra lines following Mike's tutorial. Results were great but after struggling with almost invisible 15 llb lines where do you find the dwarfs with fingers small enough (And Eyesight good enough) to tie the knot. I got there eventually but the lines are about 43 ft instead of the 45 ft I was aiming for.
As a post script the Flight Streak was rediscovered in the attic about 15 years ago as part of a clear out. Interest rekindled it was converted to electric and re introduced me to CL. It taught me how to fly again and was passed to a new flyer about 12 months ago. It and finally met its ultimate demise a few weeks ago but everything considered it had a good life. #^
TTFN
John
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Ken,
I have been using a produce call "The Knot Needle" (https://theknotkneedle.com/?gclid=CjwKCAjwsMGYBhAEEiwAGUXJadz0K80KGynCaLQe25ny1lTeoIG1cCJ0aE0BGTPEOC5GPFAs6K7iShoCF7kQAvD_BwE) to handle the fine line and it works great. The web site has lots of knot information and videos.
Best, DennisT
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Al Ferraro gave a frightening demo of breaking 80# and 100# Spectra MaxCuatro line on the 9/09/2022 Stunthangar Video hangout starting at 1:42:00. He fixed a short length between two screwdrivers and broke the lines by pulling them apart. The 100# MaxCuatro type is labeled as 25% thinner at .016".
I tried the same experiment with my green box 100# PowerPro .020" green and yellow lines. Pulling for all I was worth (the most scientific measurement I could come up with) I couldn't break them. The yellow line was bought on Amazon about 5 or six years ago.
Does the 60' of Cuatro line absorb the tension? Is Al's demo not a true test of the lines strength?
Either way I won't be using the thinner Cuatro type for flying, maybe for fishing; the stripers are running.
Ara
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Hello
I watched the Stunthangar video from Friday and I think something is wrong with the Max Cuatro lines Al brought off Amazon.
The line should be close to their rated breaking strain and testing your lines is the best way of finding an inferior 'copy' or faulty product.
With the different brands I have tried there are differences in stretch and strength you may not expect, hence the need to pull test and perhaps try them out on a old model first.
Regards Gerald
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I did the same test on some new Fins G40 65# test lines and I could break them. Not at the knot, but in the center of the line. I gave a set to Bob Hunt who flew them on his Genesis without any issues. Pulled them pretty hard to pre-stretch them. Going to make up a .015 stainless test piece and see what happens. Based on my experience flying the Spectras in combat, they should be fine for how they will be used. I love them in combat. Same set of lines for 2 years.
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Hello
My arms and elbows in particular are really score now after giving many lines the screw driver test. My pain did reveal what I sort of I expected the 50 lb line was easy to snap 65 lb was a bit harder and 85lb Fins 40G was quite painful and my Max Cuatro 65 lb put up a good fight and the Power Pro 100 lb almost defeated my arms but gave in after half a dozen goes.
Then the steel lines and the 15" steel was easy to break after a few pulls (it broke with no effort like it had been stressed after 3 goes) Last was a 3 stranded steel of 18" and it broke after a few attempts, similar to the 100 lb Spectre and I was left with aching arms but satisfied the Spectra lines were not weak especially the 85 and 100lb types.
I used the modified surgeons knot for each length and pre-stretched them first before giving successively more effort on each attempt to break them.
Pull testing airplanes is not normally sudden like this , it is more akin to combat or a model regaining line tension suddenly where we would expect lines to break or curl . From my own experience I can see why combat models need the 20G test and in practice 50lb for 1/2A (09) diesel and 65 lb for NZ slow or 100lb for full size combat seems the minimum you can trust.
Regards Gerald
PS been using Spectra for the last few years almost exclusively so Al's post got me worried.
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I made up a test piece of 7 strand stainless 0.015. I could break them by just pulling on them, but qualitatively, it seemed to be just a bit stronger that the Fins 65# lines. Not enough in my mind to worry about as the test was subjective. I may run a real test with some dead weights just to see what the difference might be.
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Dennis A,
The Knot Needle arrived yesterday, haven't had a chance to work with it yet. What type of knot have you been using? With all the options about this it is hard to find setups that you can trust. I was thinking of doubling over the line no matter what knot just to give more surface to spread the force over.
I found some 1/64" cable thimbles from McMaster that are teardrop shaped and will see how they work. I think because of the smooth shape it should put less stress on the knot, just need to make sure there are smooth edges. What do you think?
I want to set up a hanging weight test rig to see how the various knots will hold with different amounts of weight or maybe a simple pull scale.
Best, DennisT
Dennis, doubling the line to tie the knot is perfectly OK, unless it leaves too much slack in the knot. So, make sure by pulltesting before flying. Getting the knot thorougly wet before pulling. That will help show anyslack that is slipping.
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Hello
I watched the Stunthangar video from Friday and I think something is wrong with the Max Cuatro lines Al brought off Amazon.
The line should be close to their rated breaking strain and testing your lines is the best way of finding an inferior 'copy' or faulty product.
[....]
Regards Gerald
After performing a number of instrumented breaking tests using a digital scale, and also communicating with the product testing team at Shimano Fish (PowerPro is a Shimano brand), I can confidently state that the only way to obtain a full rated strength out of a braided Spectra line is to wrap the ends around a large spool or cylinder. This is what manufacturers use to test and rate their products.
The moment you tie a knot of *any kind* (and we've tried a few), the line breaking strength is reduced to 70% at best, and sometimes to 50-60%, depending on the quality of the knot.
This is not a cause for alarm or a reason to dump synthetic lines altogether. Simply make an appropriate correction when choosing which line to buy, and learn to tie a good knot.
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The line breakage shown in those video tests didn't seem to occur at the knots. It was usually several inches out from the knot.
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The line breakage shown in those video tests didn't seem to occur at the knots. It was usually several inches out from the knot.
Brent, that was my observation as well: most line breaks do NOT occur at the knot. Yet I'm convinced that it is the knot that weakens the line. I don't have an explanation as to why.
Here's what happened. I purchased a spool of 65# Maxquatro PowerPro directly from Shimano (so I assume the product was authentic). I repeatedly tested them to destruction with various knots; also with and without pre-stretching. Most failures occurred between 40-45 lbs. Disappointed, I returned the lines to Shimano. About a month later, their quality control team sent me a video of my specific spool of line being tested on their strength test machine three different times. Every test showed line exceeding the rated strength (!).
The test machine had line terminated by coiling it around large metal cylinders.
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Any true test of line strength has to be done with flying length segments, preferably the ones you will be using. There is a reason they use a short length around
spool for the ratings. It adds to the ability of the line to stretch and does not introduce a hard point. At flying length you get more stretch but you also have more opportunities for a flaw or weak spot. All we need is for it not to break at the load we will put on it and what better way than to simply test the lines you are going to use with the knots you are going to tie. We also forget that every plane is equipped with a very effective shock absorber permanently attached to your shoulder.
Ken
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Another reason to try Spectra:
I flew my Fox 35/Buster today on 65# Spectra lines attached to my trusty E-Z Just handle. It was drizzling with storm clouds looming in the distance. No shocks!
Ara
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Damp lines become very good conductors of static electricity. H^^
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Damp lines become very good conductors of static electricity. H^^
A lightning bolt has what, 450,000 Volts of electricity? :X I figure that the 6 inches of insulation provided by a rubber motorcycle tire isn't much of a dielectric n1 with that much potential in a thunderstorm, why I usually duck into a store until it passes. D>K (Except some stretches of rural New Mexico and Texas Panhandle, there is no place to duck for miles (BTDT). :o
Spectra or not, you won't see me flying during a thunderstorm! ~^
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Any updates on using the Spectra lines on larger models?
Best, DennisT
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Hello
Been using Spectra lines for all our models from 049's to 60 size for a few years now and must say the Max-Quatro by Power Pro have been my favorite with 65 for 15-40 size models and 80lb for bigger models serving very well. Biggest model flown on 80lb is over 2kg with OS60FP. The big difference to steel is the weight which you feel when changing direction or flying corners when the inertia is lower.
Me and my sons only fly steel when our local rules prohibit Spectra like racing .
Regards Gerald
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I have found sources for everything related to moving to Spectra other that the line reels! I want to make up several sets and I can't find reels at a reasonable price. You would think, since most all of the braded lines come on the same type reel that you could buy some in bulk? So, what are you Spectra folks using and where do you get them. Once upon another lifetime I had a collection of 4" line reels from worn out lines. Lost them a couple years back. Can you wrap Spectra around a smaller reel?
Ken
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I have found sources for everything related to moving to Spectra other that the line reels! I want to make up several sets and I can't find reels at a reasonable price. You would think, since most all of the braded lines come on the same type reel that you could buy some in bulk? So, what are you Spectra folks using and where do you get them. Once upon another lifetime I had a collection of 4" line reels from worn out lines. Lost them a couple years back. Can you wrap Spectra around a smaller reel?
Ken
You can buy empty line reels from MBS https://mbsmodelsupply.com/Catalog.pdf Same ones that Pylon/Sig/etc. lines come on.
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You can buy empty line reels from MBS https://mbsmodelsupply.com/Catalog.pdf Same ones that Pylon/Sig/etc. lines come on.
Thanks - I went there but I couldn't find any est. on shipping on their site, you have to place an order and give them you credit card before you know what the shipping is. It used to not matter but in today's crazy world it could be easily more than the order itself!
Ken
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Thanks - I went there but I couldn't find any est. on shipping on their site, you have to place an order and give them you credit card before you know what the shipping is. It used to not matter but in today's crazy world it could be easily more than the order itself!
Ken
Call him (Melvin) on the number on the site. His shipping is super reasonable (USPS) and he ships promptly.
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Can you wrap Spectra around a smaller reel?
As its intended use is with fishing reels usually having a minimum spool diameter of 3/4 - 1" - I think you'd be hard pressed to find a smaller spool for storage!
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Ken,
Brodak (https://brodak.com/catalogsearch/result/?q=line+reels) has both the skinny SIG style and the wide line reels (like the old Windy reels). They are a bit expensive. Seems we could build reels from a couple circle end of lite-ply with a center from either sections of cardboard tube or PVC pipe cut to 3/4" wide and glued together with a section of 1" at the center to get your finger through for winding.
Best, DennisT
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Ken,
Brodak (https://brodak.com/catalogsearch/result/?q=line+reels) has both the skinny SIG style and the wide line reels (like the old Windy reels). They are a bit expensive. Seems we could build reels from a couple circle end of lite-ply with a center from either sections of cardboard tube or PVC pipe cut to 3/4" wide and glued together with a section of 1" at the center to get your finger through for winding.
Best, DennisT
I gave that some thought but if you dig deep enough on line eventually you find something. I found the empty reels that they sell the line on for $1.50 each in quantities of 5. Shipping $5 for the lot. I ordered 10. Thanks for all of the suggestions.
Ken
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I gave that some thought but if you dig deep enough on line eventually you find something. I found the empty reels that they sell the line on for $1.50 each in quantities of 5. Shipping $5 for the lot. I ordered 10. Thanks for all of the suggestions.
Ken
Hi Ken,
Would you mind sharing your source with us?
Dennis
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If you have a 3d printer, there's reel files on thingiverse.
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Ken, I noticed you were a bit curious on the amount of stretch between Spectra and Ukraine lines. I have no idea what Ukraine lines are, but I have some comparative data on Spectra vs stainless steel. I have also been interested in this.
I just happened to be making up some new Spectra lines this morning, so while I was at it, I did a simple stretch comparison with my digital fish scale. I have no idea on the amount of pull that is typically seen during flight, so I used 5 lb (for reference only) on a single line, which would equate to 10 lb pull on a model in the air. Here is what I came up with:
PowerPro Spectra (new/unused lines)
65# test line
58' long loop to loop
5 lb load
Stretch right at 2"
0.015 diameter stainless steel (new/unused lines)
58' long connector to connector
5 lb load
Stretch right at 1-1/8"
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There is nothing wrong with tying the Spectra lines to the connectors directly using Larkshead knots (Lenny Loops!), it works well.
I have started using welded rings (NOT split rings) at each end of the lines because it makes it pretty easy to just use regular clips for all of the hardpoint handles. Here's what I am doing:
I am using SPRO Power Welded Rings, several sizes are available, I like the #3.5 size rated at 266# I get them from Tackle Direct:
https://www.tackledirect.com/spro-power-welded-rings.html
I do not know how to place the pictures in line with the text so I will have to show this the hard way.
* First pix is of the welded ring. Its about a 5/32" ID, the wire about .015",
* After tying the Modified Surgeons Knot, you get two identical loops. Pass them trough the welded ring from opposite directions
* Slip some forceps through the loops and...
* Grab the welded ring with the forceps.
* Using the forceps, pull the welded ring back through the loops, you should see the Larkshead knot starting to form.
* SPIT ON IT, and pull it tight. I usually install these the last thing before doing the stretch/normalization on the lines; that is I pre-stretch the lines with the rings in place.
* You are left with a tidy little ring to pass a normal line clip through. Even if you tie the line clips at one end of the lines, this will make it real easy to use regular line clips at the other end to get your neutral setting. if you are using scissors style clips, like the Derrick Moran/Jim Lee clips the wire ring is physically a little larger and less likely to pass between the scissors.
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There is nothing wrong with tying the Spectra lines to the connectors directly using Larkshead knots (Lenny Loops!), it works well.
I have started using welded rings (NOT split rings) at each end of the lines because it makes it pretty easy to just use regular clips for all of the hardpoint handles. Here's what I am doing:
I am using SPRO Power Welded Rings, several sizes are available, I like the #3.5 size rated at 266# I get them from Tackle Direct:
https://www.tackledirect.com/spro-power-welded-rings.html
I do not know how to place the pictures in line with the text so I will have to show this the hard way.
* First pix is of the welded ring. Its about a 5/32" ID, the wire about .015",
* After tying the Modified Surgeons Knot, you get two identical loops. Pass them trough the welded ring from opposite directions
* Slip some forceps through the loops and...
* Grab the welded ring with the forceps.
* Using the forceps, pull the welded ring back through the loops, you should see the Larkshead knot starting to form.
* SPIT ON IT, and pull it tight. I usually install these the last thing before doing the stretch/normalization on the lines; that is I pre-stretch the lines with the rings in place.
* You are left with a tidy little ring to pass a normal line clip through. Even if you tie the line clips at one end of the lines, this will make it real easy to use regular line clips at the other end to get your neutral setting. if you are using scissors style clips, like the Derrick Moran/Jim Lee clips the wire ring is physically a little larger and less likely to pass between the scissors.
Thank you Dennis!
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Help.
All the Youtube videos on tying the double surgeon knot I used to go to now say "Video no longer available." I've never been able to remember how to tie any knots except shoestring knots and square knots. I need to watch someone do the double surgeon knot to get it right and getting it wrong may make for an ugly day at the flying field. All the videos that come up on Youtube when you search for "double surgeon's knot" show how to tie two different lines together rather than how to make a loop at the end of one line.
Anyone know of a currently available video on how to tie our control line double surgeon knot? Anyone willing to make a new video for us?
Thanks,
Joe Ed Pederson
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Help.
All the Youtube videos on tying the double surgeon knot I used to go to now say "Video no longer available." I've never been able to remember how to tie any knots except shoestring knots and square knots. I need to watch someone do the double surgeon knot to get it right and getting it wrong may make for an ugly day at the flying field. All the videos that come up on Youtube when you search for "double surgeon's knot" show how to tie two different lines together rather than how to make a loop at the end of one line.
Anyone know of a currently available video on how to tie our control line double surgeon knot? Anyone willing to make a new video for us?
Thanks,
Joe Ed Pederson
Joe, there is an updated video. I will try to find and post.
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Thanks, Colin.
Joe Ed
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Thanks, Colin.
Joe Ed
Sorry Joe Ed but the video I mentioned is also not available. Not sure why.
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Hi Ken,
Would you mind sharing your source with us?
Dennis
Haven't arrived yet so I can't vouch for them yet but here it is:
https://www.amazon.com/dp/B08NTRBQXR?ref=ppx_yo2ov_dt_b_product_details&th=1
Ken
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Help.
All the Youtube videos on tying the double surgeon knot I used to go to now say "Video no longer available." I've never been able to remember how to tie any knots except shoestring knots and square knots. I need to watch someone do the double surgeon knot to get it right and getting it wrong may make for an ugly day at the flying field. All the videos that come up on Youtube when you search for "double surgeon's knot" show how to tie two different lines together rather than how to make a loop at the end of one line.
Anyone know of a currently available video on how to tie our control line double surgeon knot? Anyone willing to make a new video for us?
Thanks,
Joe Ed Pederson
I don't have a video for you, but if you go to the AMA web site and the rules book section, then go to the section for C/L and making flying lines. It has a diagram for a knot there that is approved by thy AMA for Spectra type lines. I have never been a sailor or a Boy Scout so I am "knit challenged" also!! I have been able to make this one work when making the few sets of lines for 1/2A stuff that I hve made. Check it out and try it on some regular string for practice.
Type at you later,
Dan McEntee
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Thanks Dennis - Ordered 20. A bit pricy but exactly what I was looking for.
ken
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Does this series of photos help with tying the surgeons knot? Hope the video reappears soon.
Steve
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Does this series of photos help with tying the surgeons knot? Hope the video reappears soon.
Steve
You convinced me. I am using a Palomar Knot! Tied thousands of them on fishing tackle and don't recall one ever slipping, mainly because the stuff we fished for usually cut the leader wire first!
Ken
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Haven't arrived yet so I can't vouch for them yet but here it is:
https://www.amazon.com/dp/B08NTRBQXR?ref=ppx_yo2ov_dt_b_product_details&th=1
Ken
They came today and are exactly what I expected. "Identical" to the ones Power Pro and Fins come on.
Ken
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Another question. Does using a felt tip pen on Spectra in any way weaken them?
Ken
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So far mine have held up after using felt tip to mark the lines. D>K
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I have also used felt tipped marker on Spectra (FINS 40G) to mark the end of the line with no issues. Flying those lines for over a year.
Best, DennisT
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It was interesting reading the last round of comments. Spectra(gelspun polyethylene with VERY long molecules). You can actually see them if you break a line and have a good magnifying glass handy. The molecules are still there, and visible if you get the lighting right and the angles right.
The keys are to remember that the line can be damaged by heat. That means something around or over 300^deg. F. The line will hold every bit of its breaking strength as long as it isn't melted, or abraded enough that you can see individual fibers. I was really pleased when I could test the Spectra as F2D lines. It was a real treat to see both sets of lines stretching exactly the same- about 2.5in.
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Is there 1 place I can go and get all the details of tying my Spectra lines? Going through thread is torture.
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Is there 1 place I can go and get all the details of tying my Spectra lines? Going through thread is torture.
This is the knot that has been used for years in combat. Picture provided by Phil Cartier.
Use the exact same motions as shown, just double the material over to start with. Mark it with a sharpie to establish the exact length you want. Spit on it when you draw it tight. Don't use superglue or epoxy. Attach to your line clip with a Larks Head knot.
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Are there any bad reports on the single Palomar knot? My fingers and eyes are not up to the task for some of these other exotic knots.
ken
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This is the knot that has been used for years in combat. Picture provided by Phil Cartier.
Use the exact same motions as shown, just double the material over to start with. Mark it with a sharpie to establish the exact length you want. Spit on it when you draw it tight. Don't use superglue or epoxy. Attach to your line clip with a Larks Head knot.
And what is a Larks Head Knot? Some of us were never sailors nor Boy Scouts!! y1 In my limited use of Spectra type line, I'm tying to a small ring, and then attaching line clips to that, sort of traditional method I guess, so I can change styles of connectors easily.
Type at you later,
Dan McEntee
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The disadvantage to the palomar knot is its difficulty in achieving the precise line length you desire. The popular modified double loop figure-8 knot allows you to mark where you want the line length to be, and to actually acheive that feat. Practice on a segment of rope to learn the motions.
You use the combat tested, modified surgeons knot to establish the line length you need. Then use the simple larks head knot to connect the line to the clips.
(Eagle Scout bonus trivia) The larks head is a very simple common knot and is also known as a cow hitch. Recently the knot has been dubbed the Lenny Loop, from Len Bourrel on the Stunhanger video hangout.
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[quote
Also why use a thimble? Would it not be better to just tie right to the line clip?
Some guys have concern about securing to a line clip because of the tight radius. The thimble will spread the load. So far in combat the only area of concern has been where the line passes thru the leadout guide. In time chaffing has occurred, which will cause an eventual failure.
Phil C is really the authority on the knot. He says modified surgeons, thats alright by me!
Tom
securing to a line clip because of the tight radius/
Tom- I tried about 50 times to find a good termination with Spectra that was readily available. The best thing seems to be to make the loops about 1/2in diamter, finished. Bigger is OK if you need or want it. It's best to wet the knot and gently pull it tight and snug so it doesn't really have a chance to pull it tight.
A lot of people are attracted to other methods, but it really doesn't seem to be needed, unless you have off the wall needs, such as an 80lb stunter!
Cheers
Phi Cartier
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After doing some research, I’ve found that I need the 65lbs spectra lines. I will fly Vector, Cardinal, Banshee, XEBEC with engines ranging from LA 25, Enya SS30, Enya 35XS, Enya SS40.
I’ve read the most recommended brand is Power Pro MaxCuatro, but it’s hard to find it here in Indonesia.
I can only find these (see pictures). What do you think about it? Do you have any other recommended brand?
Currently I fly with Sullivan 7 strand stainless steel cable 0.015x60 feet.
(https://i.postimg.cc/LXvC696C/36356456-1839-4-D56-B987-E2-AC757397-CB.png) (https://postimg.cc/MMMb98BV)
(https://i.postimg.cc/6q3H8k89/BE284424-AE0-E-423-E-90-D3-F2-A63-D35-E8-F2.png) (https://postimg.cc/bD70MF0M)
(https://i.postimg.cc/zfZPx2cj/FB07-C64-D-841-A-401-D-AAEC-181-E8728133-F.png) (https://postimg.cc/zy7jB75b)
Best,
Kafin
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Kafin,
I've been using the green box Power Pro ever since abandoning steel lines about five years ago. I use them for 1/2A(30 lb. test) up to combat (100lb. test). The green box Power Pro was the only choice accepted by the stunt community back then and I have enough that I haven't tried or compared the later versions. I believe Dennis A. has given the Green box Power Pro the 'OK'. The only mishap I've had with the Power Pro is on my Old Time Taurus. The wire leadout guides were quite rusty and severed both lines.
I've mentioned on here before that analyzing, testing, comparing, agonizing over knots etc. just prolongs your using them. They're a proven entity. Make up a set and use them; for one, your line kink dilemma will instantly disappear.
Ara
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Help.
All the Youtube videos on tying the double surgeon knot I used to go to now say "Video no longer available." I've never been able to remember how to tie any knots except shoestring knots and square knots. I need to watch someone do the double surgeon knot to get it right and getting it wrong may make for an ugly day at the flying field. All the videos that come up on Youtube when you search for "double surgeon's knot" show how to tie two different lines together rather than how to make a loop at the end of one line.
Anyone know of a currently available video on how to tie our control line double surgeon knot? Anyone willing to make a new video for us?
Thanks,
Joe Ed Pederson
Jow Ed
Mike Stinson re posted his knot tying video on YouTube. I edited post #1 in this thread to link it and it is also attached here:
https://www.youtube.com/watch?v=d1l_fAPV6lA
GOOD LUCK!
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Thank you Dennis. I watched this video several times now and it looks better than knot I am using. My knot from another post leaves only a single strand of line in the loop. This one will make me feel better. Nood to get to go get some te pound for my 1/2A's. H^^
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After doing some research, I’ve found that I need the 65lbs spectra lines. I will fly Vector, Cardinal, Banshee, XEBEC with engines ranging from LA 25, Enya SS30, Enya 35XS, Enya SS40.
I’ve read the most recommended brand is Power Pro MaxCuatro, but it’s hard to find it here in Indonesia.
I can only find these (see pictures). What do you think about it? Do you have any other recommended brand?
Currently I fly with Sullivan 7 strand stainless steel cable 0.015x60 feet.
(https://i.postimg.cc/LXvC696C/36356456-1839-4-D56-B987-E2-AC757397-CB.png) (https://postimg.cc/MMMb98BV)
(https://i.postimg.cc/6q3H8k89/BE284424-AE0-E-423-E-90-D3-F2-A63-D35-E8-F2.png) (https://postimg.cc/bD70MF0M)
(https://i.postimg.cc/zfZPx2cj/FB07-C64-D-841-A-401-D-AAEC-181-E8728133-F.png) (https://postimg.cc/zy7jB75b)
Best,
Kafin
Hi Kafin
The difference between PowerPro and Maxcuatro is that the Maxcuatro is slightly smaller. For example the 50# Test Maxcuatro is .012", regular PowerPro & Slick8 are .014", Maxcuatro 65# is .014" regular PowerPro & Slick8 is .016" Any of these line sizes are 1/5th the weight of Stainless Steel. For your fleet of airplanes either the 50# or 65# will work fine.
Is PowerPro available to you? If so then that's a great choice.
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Kafin,
I have used the FINS 40G line (https://www.finsfishing.com/products/fins-40g-fishing-braid-65-100lb) for over a year now and find it is a very strong, smooth line that is thinner than the PowerPro and Maxcuatro line for the same #test rating. For their 65# test line the 40G line has a diameter of 0.011". I use the FINS 40G 45# test (diameter 0.009") for my 34oz ship. I generally figure the line # weight by taking the weight of the ship in LBs x 10 x 2 then get the close line available.
I use the thinner lines to save battery draw. Compared to 0.012" diameter braided cable my results showed 4 -6% less battery draw. This allowed me to use a smaller battery pack that saves 1 - 2 oz (depending on standard pack that is used). For a sport ship, doesn't mean much, for competition it is very important. Plus you get to reduce tip weight by at least half.
Best, DennisT
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Modified Surgeons Knot
The Mike Stinson video and Steve Glass’s photos (post 210) were both very helpful to learn to tie the modified surgeons knot. Thank you both.
I created (and attached) a brief step by step document that helps me when I tie the knot.
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With a lot of interest I have been reading this thread about the Spectra lines. good experimenting and increased insights since the first post of Dennis. Thank you all! I feel that thinner and lighter lines will result in a better total package after trimming. I always felt that the lines were a necessary evil. If I just could reduce this evil...... The proof of the pudding will be in the eating. With little knowledge on the subject (before reading this ) I purchased a 125 meter reel of 50 lbs power pro line. The strength appeared better than the 015 PAW Staystrate tinned lines I am using now, so i think I am safe. I am not so much worried about line stretch because in the air the stretch will be equal in both lines and I don't think that the delta in line tension between both lines while cornering will be very large for models with a normal C.G. location and proper sensitivity. Proabably a tat more steering is required, but nothing too dramatic. It is a feeling. I don't have the metrics. So do you consider it wise to use this 50Lbs lines for a 70 ounce model with a ST51 and 5.3 lap times? Linetension is about 3G. Thanks again
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Paul,
To form your own fact based opinion consider a test. The AMA pull test requirement is 10G. In your case 700 oz (43.75 lbs.) total. Approximately 22 # per line
Make a small sample, just a few feet long and see if passes the 22# test. My personal preference is to verify something greater than 10G.
My personal experience is that the samples fail well under the rated load, 50 # in your case.
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With a lot of interest I have been reading this thread about the Spectra lines. good experimenting and increased insights since the first post of Dennis. Thank you all! I feel that thinner and lighter lines will result in a better total package after trimming. I always felt that the lines were a necessary evil. If I just could reduce this evil...... The proof of the pudding will be in the eating. With little knowledge on the subject (before reading this ) I purchased a 125 meter reel of 50 lbs power pro line. The strength appeared better than the 015 PAW Staystrate tinned lines I am using now, so i think I am safe. I am not so much worried about line stretch because in the air the stretch will be equal in both lines and I don't think that the delta in line tension between both lines while cornering will be very large for models with a normal C.G. location and proper sensitivity. Proabably a tat more steering is required, but nothing too dramatic. It is a feeling. I don't have the metrics. So do you consider it wise to use this 50Lbs lines for a 70 ounce model with a ST51 and 5.3 lap times? Linetension is about 3G. Thanks again
Paul, the AMA has a good guideline for Spectra rated strength vs model weight. For a 70 oz model, I would use Spectra rated at 100 pounds. My heaviest model is a Vector 40 at around 60 oz. I fly it with 65# test Spectra lines.
Earlier in this thread I posted the actual table for reference.
And make sure you make up the end double loops properly. The how-to is also in this thread.
I also have never-ever had a Spectra line failure. But also, to be on the safe side, I have been replacing my lines annually as additional safety factor since the lines are so cheap to make-up.
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Hello
I tend to be careful/cautious when selecting Spectra lines
1/2A-09 size 30-50lb
Small 15-35 size models I use 65lb
Medium 35-45 size 80lb
Large models 85-100lb line
Stretch , line diameter and feel vary a bit with brands, even at the same test weight.
Regards Gerald
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Hi Paul
My current line usage aligns pretty close to what Gerald recommended. The AMA guideline (check out the CL General Rules for the table) is also not bad.
I fly a 71 oz SV-11 on 100# Original PowerPro. I have a 67 oz airplane that I am flying on 80# Maxcuatro. I haave a 55 oz airplane that I fly on 50# line, but I want to try it on 65# line to see if it makes a difference
As a generality I think I am a little cautious about choosing Spectra, but my primary concern is stretch more than strength. I flat out do not know with certainty what the lower limits are.
My current (UNSCIENTIFIC!) rule of thumb (and this is a work in progress!) is that I take the weight of the airplane in ounces and put it on line with a similar rating (rounded up) in pounds. Thus, for my 70 oz airplane I would look for 70# line, which does not exist, so I would round up to 80#. I plan on trying the 70 oz airplane that I currently fly on 100# and try it on 80# and see if there is any risk in stretch.
Similarly, by this standard, my 55 oz airplane is a little overweight for the 50# line - thus I want to switch it to the 65# line.
Another way to look at it: use the 10G pull test as a guide. The pull test is likely the highest loading the lines should ever see. With a 70 oz airplane, that is roughly 4.5#, the pull test is 45 pounds. When I stretch-normalize my lines I pull to 50% of rated load on each line and hold for a count to 100. Thus on a 100# line I would pull it to 50# and hold. That means that I have TESTED each of my lines to 100% of pull test, meaning that on two lines I have a margin of double the pull test.
All a long winded way of saying I think the 50# line you want to use is much smaller than I would use.
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Let me piggy back on what Dennis said. When you consider line strength it is too easy to think that you have two lines and use a size that splits the load. Consider what happens if a single line fails which is more likely to happen with a spectra knot slipping than a properly wrapped metal line. 100% of the flight load immediately shifts to the other line with a snap as the bellcrank reaches it's limit. Odds are high that the plane splats but it is 100% if the 2nd line breaks and your pride and joy becomes an unguided missile.
IMHO you should use a line size that will pass the pull test plus a safety factor with only ONE line. Dennis's size guides will do that.
Now for my latest question (I hate having 60+ years flying PA and being a rookie on the new technology HB~>).
I recently ordered some metal o-rings for line connectors. I was advised to use a #5 ring. They were out so I ordered a #4. Is the #4 too small?
ken
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Thank you all. I will ty this one: wft-kg-strong-braid-green-100m-0-25-mm-39kg
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Thank you all. I will ty this one: wft-kg-strong-braid-green-100m-0-25-mm-39kg
Paul, one other thing to think about. I am not familiar with that particular brand, but it looks like it has a green color. A green color will be very difficult to see on the ground.
I use Power Pro Spectra and the hi-visibility yellow color, or the blue color. Both are easy to see when the lines are on the ground. The yellow is best. And some people even use one color for up and a different color for down. Totally a personal preference.
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One thing I learned a hard lesson on Spectra, buy from reputable sources, and please, I am not speaking about anyone here but my own experiences. Maybe 6, 7, 8 years ago, I bought some bargain stuff on the 'bay, from a Far Eastern source. They had good ratings, so felt, "why not and save some money?". It was 70 lb. strength stuff, yellow, looked genuine. But, pulled out to 60 feet, it stretched a couple inches, but seemed strong enough.
It was a huge mistake. On my Ringmaster with Testors .35 Red Head pulling nicely in a fast 4 cycle, one line stretched more than the other. I was giving full down and still the plane was making a very tight high elevation loop less than half the diameter of the circle with engine breaking into 2 cycle. I was doing less than 2 second laps, very dizzying, until the tank ran dry. Lines were now not as taut, now I had down control. Brought it in for a normal dead stick glide.
Then on out, learned no longer to buy like that. If someone here says, "buy from this source" and the advising is reliable, I'll follow their advice even if it costs me more. Internet buying can be a can of worms, your planes are worth more than chancing them on cheap stuff. n1
I also found this true in buying musical instruments. Those bargain $40 guitars with free shipping I bought were roughly finished, they didn't even sand the rough cut string winder holes. Cheap is cheap, get what you paid for. n~ D>K R%%%%
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The yellow is best. And some people even use one color for up and a different color for down. Totally a personal preference.
You are just the person I was looking for in my post below. Do you find the yellow distracting in flight? I am about to make up some new sets and I am concerned that they will be *too* visible.
Ken
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You are just the person I was looking for in my post below. Do you find the yellow distracting in flight? I am about to make up some new sets and I am concerned that they will be *too* visible.
Ken
Hello Ken I usually use Yellow Max Cuatro and do not find the color distracting, some have faded to white with age. Sparkly new steel lines especially brass coated ones and shinning in the sun are very visible but still not distracting as I focus on the model .
Regards Gerald
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You are just the person I was looking for in my post below. Do you find the yellow distracting in flight? I am about to make up some new sets and I am concerned that they will be *too* visible.
Ken
Ken, the yellow color Spectra is not distracting in flight at all. Totally not an issue in flight. Just a lot easier to see the lines when they are laying on the ground.
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I am curious if the single Palamor knot is OK.
Ken
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I am curious if the single Palamor knot is OK.
Ken
Ken, I don't know if the Palamor knot is OK or not. But why not just use the simple-to-do modified surgeon knot. It is the right one to use for Spectra lines. I have never-ever had a line failure or knot come loose.
See the video posted by Dennis a few posts above.
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I am curious if the single Palamor knot is OK.
Ken
Is this the knot that is posted on the AMA web site and the section on the use of fishing line?? The names of all these knots are confusing becasue some of them are for the same knot or at least it seems so. I was never a sailor or a Boy Scout!
Type at you later,
Dan McEntee
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Is this the knot that is posted on the AMA web site and the section on the use of fishing line?? The names of all these knots are confusing becasue some of them are for the same knot or at least it seems so. I was never a sailor or a Boy Scout!
Type at you later,
Dan McEntee
No, that is a "Uni" knot. The Palomar is tied much differently. Fishing sites rate the knots about equal with the Uni a bit stronger, but the Palomar is easier to tie, especially in the field. Now I am starting to wonder about the Surgeon's Loop knot. It is the strongest of them all according to some. Don't the combat guys use that knot?
Ken
Ken
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Hi Ken
I know a couple folks who are proponents of the Palomar knot - I tried it and could not get the hang of it! The Palomar can be tied to a specific length, and it sounds like you have experience with it. Ultimately you (all of us!) need to test/prove the knots by pull-testing via the "pre-stretch" setting the braid. I use an electronic "Dr Meter" pull scale I got off Amazon. The scale assures that I am truly pulling to the desired target load. I connect my lines end to end so I can pull both lines at te same time to exactly the same load.
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YESTERDAY'S TEST
Up to now I have selected my line sizes based mostly by "rationalized guess". Been pretty lucky so far, but that method is not terribly scientific! Since I pre-strectch all of my Spectra lines to measured loads well in excess of the 10G pull test, I am pretty certain that I have a good strength margin. i have been much less certain about whether stretchiness is coming into play. I learned a few years about line stretchiness when i switched from 19 strand cables to 7 strand cables. That difference was so great that I immediately tossed ALL my my 19 strand lines so I could never use them again! None of my Spectra lines ever left me feeling that line stretch was an issue - until yesterday.
I have a 55 oz. Mo'Best that I flew on 50# x 63' Maxcuatro since its first flights last spring - flies well. Yesterday I flew the Maxcuatro 50# (.012") back-to-back with FINS Spin5 rated at 65# (.014" dia). It seemed to me that the 65# line flew a little better by a very small margin. I do not think I would have been able to tell any difference unless I had flown it back-to-back, certainly nowhere as evident as the difference between 19 strand versus 7 strand SS cables I experienced previously. The only down side was that the larger line consumed about 100 mah more - but the sample size is exceedingly small!
How will I apply the above? The MB weighs 55 oz, or 3.44lb, its 10g pull test is 34 lbs. That is roughly the same as the 32.5 lb pre-stretch load I routinely use on 65# Spectra lines. Thus my NEW criteria for selecting Spectra line sizes will be to take the pull test, double it, and use it to select the Spectra Line rating. That is still simplistic. There are other factors like braid construction that may factor in, but hey, you gotta start somewhere! I had thought about also adding 80# line to the test (and may yet) but I doubt that it would be detectable. However I have some 50# and 65# lines with different construction & brands that probably ought to be tested back-to-back.
Has anyone else done any similar comparisons?
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Hi Ken
I know a couple folks who are proponents of the Palomar knot - I tried it and could not get the hang of it! The Palomar can be tied to a specific length, and it sounds like you have experience with it. Ultimately you (all of us!) need to test/prove the knots by pull-testing via the "pre-stretch" setting the braid. I use an electronic "Dr Meter" pull scale I got off Amazon. The scale assures that I am truly pulling to the desired target load. I connect my lines end to end so I can pull both lines at te same time to exactly the same load.
My father used to own a fishing tackle company in Florida. You can get pretty close if you put some marks on the lines and pull them to the marks. The trick with the Palomar is wetting the line and carefully taking out the slack from both lines. You sort of work the knot into place then yank it. The double is a waste of time in my opinion. It can be really frustrating and only marginally stronger. I have do all of my stuff in my office so line making time is in the hall after everybody goes home. I use 4mm rings and hook both of them to a single line clip and attach that to a door handle. Pull till they stop stretching an about 3 timed what the plane pulls. I was shocked on my first set how much they stretched, then didn't. I wonder if you stretched them wet then let them dry if they might be even better. I am going to try that.
The new ship is borderline between 80# and 100#. Right now I am on 80# and not having any problems. Using your new ultra scientific method I should be on 83#. The tackle store was out of 83# so I am sticking with 80#. I am not sure at my age if a little stretch is all that bad. LL~
Speaking of the new ship, the Canard is exceeding my expectations. Makes me wonder why you didn't continue with yours. Rough trim is done and full patterns are being flown. I never expected the tracking. Corners, yes, but tracking, locking and no hunting was not expected. Uses a lot of battery though.
Ken
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Dennis,
The method you described for selecting line size is what I have used with the FINS 40G lines. When you look at it you can just take the ship weight in oz and get the next size up in LB test rating.
Best, DennisT
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I wonder if you stretched them wet then let them dry if they might be even better. I am going to try that.
I think the stretching exercise helps align the strands of the braid. I think wetting it would help but I have not tried it yet.
The new ship is borderline between 80# and 100#. Right now I am on 80# and not having any problems. Using your new ultra scientific method I should be on 83#. The tackle store was out of 83# so I am sticking with 80#. I am not sure at my age if a little stretch is all that bad. LL~
Just to confuse it a little more, there might be a difference in stretch between the "normal" size braids, like original PowerPro & WindTamer versus the smaller diameter braids with the same rating like Maxcuatro, Spin5 or 40G.
Speaking of the new ship, the Canard is exceeding my expectations. Makes me wonder why you didn't continue with yours. Rough trim is done and full patterns are being flown. I never expected the tracking. Corners, yes, but tracking, locking and no hunting was not expected. Uses a lot of battery though.
Ken
I never built one, my brother did. I flew it once and liked it but I could never get on board with the appearance. Then when I came back I finally started to built one but I did not like where the weight was going. One difference between yours & his was that his canard was a hinged surface while yours is a stabilator. INTERESTING!
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One difference between yours & his was that his canard was a hinged surface while yours is a stabilator. INTERESTING!
I moved my response to the Endgame III First Flights. I wanted to let you know the why for the stabilator but did not want to start the dreaded "thread drift..."
https://stunthanger.com/smf/open-forum/endgame-iii-first-flights/msg657156/#new
Ken
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Another use for Spectra line.
I also use Spectra for my stooge pull line. Works great since it does not stretch when pulled. I use the hi-Vis yellow so it is easy to see on the ground.
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great idea, i will swap out my stretchy nylon stooge line for Spectra ASAP
great idea ,will swap my stretchy nylon stooge line for Spscta ASAP
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great idea, i will swap out my stretchy nylon stooge line for Spectra ASAP
You won't be disappointed.
Originally, I used a nylon cord. It stretched so much I could not release the model. Changed to Spectra and never looked back!!
I fly w/ 65# test line and just used the same for my stooge. Also use the same knots as my flying lines.
And I just use a normal line spool to store the line. Easy to roll up when done.
great idea ,will swap my stretchy nylon stooge line for Spscta ASAP
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More people are looking into using the Spectra lines. I have been flying the FINS 40G line for almost a year and a half with no issues. I have switched between cable and the FINS and found no difference in feel or control.
The knot method shown in Michael Stinson video the Modified Surgeons knot, has been solid with no slip or change in length of the knot and it is an easy way of getting both lines the same length. The first three knots are always easy, but until I saw this video getting the last knot at the right length was very difficult. Mike's method is straightforward and a very strong, safe knot.
Best, DennisT
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Are there any bad reports on the single Palomar knot? My fingers and eyes are not up to the task for some of these other exotic knots.
ken
The only times I have had trouble with the Palomar knot (slipping), was when using Fluorocarbon fishing line. I changed to using either the Trilene knot or the improved clinch knot, and I actually can't tell you the difference. The Palomar is a quick and simple knot to tie. After a few years, I gave up the Fluorocarbon line entirely, so my knot choice got simpler.
Recently, a bass fishing newsletter I am subscribed to had test results for breaking strength of various brands of braided Spectra lines. The interesting thing was that many of the samples tested broke at well OVER the rated number. How they did the tests, I'm not sure, but I strongly suspect that no knots are involved. Perhaps there is a YouTube video showing some knot tests with the Berkley knot testing machine? Anybody? I'm not a fan of Berkley lines, FWIW.
IMO, the color you choose depends a lot on your flying surface. If your grass is green all year, then the fluorescent yellow should be great, but if your grass turns yellow/brown in Summer, then I'd suggest the Red or Vermillion for all year flying. When I flew F1A glider, we used 50 or 60 lb test monofil, and hi-vis yellow was available, but so was a hi-vis orange, but it was more difficult to get. Lots of folks used the yellow, but I found the orange was much more visible, both here in the PNW and also in Central California where the bigger contests were held. Potentially, your choice of sunglasses could also influence the visibility of your line on the ground. y1 Steve
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Whether SS cable or Spectra, I like having two spools of line to start with. That lets me make-up one end then spool out the pair of lines to make up the other end. With Spectra I started buying dual spools in contrasting colors, on the logic that one or the other lines would always be visible regardless of background. Recently, I got a couple spools of FINS Spin5 (65#). I honestly did not realize it at the time, but discovered that I had inadvertently created the new non-metallic 21st century variant of "Ukrainian" lines... (sky blue side UP of course)
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difference. The Palomar is a quick and simple knot to tie.
I would not call it a scientific test but I inspect my knots before and after every session. So far there has been zero slippage on any of the knots and some of them are trimmed way too short (soon to be replaced). With the Palomar I can get the lines within 1/4" every time and sometimes closer. The trick is to mark the lines where they will end up on the eyelet and massage the knot till it is tight on the mark. With the Palomar that mark is the end of the 1st fold and that is what loops over the eyelet. From there a caveman can get them equal. With the other knots, even the double Palomar, it is a real challenge to get them even close. FYI, I picked the yellow since all of my flying is over blacktop but what I was not expecting was how well I see them in the air and how little they stretch once you get them broken in. I have even gotten used to the humming.
Ken
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There has been a lot of discussion in this thread about how people are breaking lines at under the specified line strength. Here is some background text and video by Dave Burch, the "Braidman" on how FINS tests their lines:
https://www.finsfishing.com/blogs/the-science-of-fishing-braids/line-strength-test
He shows how they test and rate their lines and notes that the average break strength is typically much higher than the rating. He then states that with knots the lines will break some 30% lower load than tested - depending on the knot used and skill in tying that knot.
Personally I have gotten over the strength issue - I routinely pull test my lines at a load roughly double the expected pull test before they ever make it to the field so I know the lines are capable before they ever make it into the air.
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Anything new in Spectra land? Anyone try some other brands with higher strength and thinner diameters? I have been flying the same set of FINS 40G 40Lb test lines on my Ringmaster for over a year and a half with no roughness or fraying.
Has anyone found a good way to wipe down the lines to remove normal finger oil from running the lines down on the way to the handle?
Best, DennisT
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I have been toying with the idea of using 200# Power Pro Downrigger line for leadouts. With the cutout bellcranks and brass pully thimbles with smooth bolts holding the thimbles I think would be a better solution than wire. Care would have to be taken that they didn't rub on anything, but we do that anyway. A perfectly smooth leadout guide that is not subject to cutting would also be necessary. Planes are heavier and turn under force much more than it was in "the day". All of these recent equipment failures bother me. Braded fishing line is considerably less prone to break from repeated bending and has much better abrasion traits.
Ken
Just a thought - Ken
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Hello I have seen Kevlar leadouts on the Hangouts (Trian's work) and did the same on a few small models.
Perhaps 300-500lb Kevlar for bigger models?
On cleaning oil covered Spectra lines I found normal dishwashing liquid works when I washed some well used sets that had become sticky with my oily hands.
Best method to avoid getting oil on them would be fly electric only or get some one with clean hands to wind them up or unroll/untwist them.
Regards Gerald
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Today I got hit with a surprise heavy rain right after takeoff and something happened that prompts me to ask if the stretch characteristic of Spectra lines is different if they are wet. All of my corners (inside and outside) were what appears to be under turned with a bounce back to the flat which is a characteristic of stretchy lines. I don't normally under turn corners. I find other ways to screw up the pattern, but I also don't fly much in the rain. This was the first time with Spectra. In the fishing world they are known for their lack of stretch which is in water where it is *wet*. Is it possible that they stick some when wet? Line tension was a bit lower which tells me that they were heavy which might have been a contributing factor. Any thoughts other than why would you want to be connected to a 24 volt battery by wet lines?
Ken
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Hello
We have often flown with wet Spectra lines (very normal for NZ), they do stick but wet steel lines are worse for sticking.
They do absorb water and feel heavier but dry out quickly without the rust problem.
Here in Auckland it is wet for most of the year (it would seem) so muddy spectra lines are common but I have often cleaned this and oil build up off them with a detergent wash.
Regards Gerald
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Hello
We have often flown with wet Spectra lines (very normal for NZ), they do stick but wet steel lines are worse for sticking.
They do absorb water and feel heavier but dry out quickly without the rust problem.
Here in Auckland it is wet for most of the year (it would seem) so muddy spectra lines are common but I have often cleaned this and oil build up off them with a detergent wash.
Regards Gerald
Thank You! That explains why I was under turning the corners, heavy sticking lines! Lesson learned.
Ken
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I have only gotten my Spectra lines wet in morning dew on the grass and some light drizzle in flight. No issues at all with stretch or stickiness. This weekend I think I will wip my lines down - first time ever - using alcohol & a paper towel just like I used to do with SS cables. Anticipating that it might take some of the dye off???
Pertaining to an earlier post Ken C made, I have Spectra leadouts in a couple of the new birds, pix coming when I can get them off the phone...
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I have only gotten my Spectra lines wet in morning dew on the grass and some light drizzle in flight. No issues at all with stretch or stickiness. This weekend I think I will wip my lines down - first time ever - using alcohol & a paper towel just like I used to do with SS cables. Anticipating that it might take some of the dye off???
Pertaining to an earlier post Ken C made, I have Spectra leadouts in a couple of the new birds, pix coming when I can get them off the phone...
Two flights today with dry lines - no under turning. I think it was the line weight. One curious thing. In the rain it flew a 5.2 lap. No changes to any settings and today it flew it's normal 5.4. Is it possible that wet Spectra has less drag than dry Spectra? Or does Mike's stopwatch need a new battery? LL~
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Two flights today with dry lines - no under turning. I think it was the line weight. One curious thing. In the rain it flew a 5.2 lap. No changes to any settings and today it flew it's normal 5.4. Is it possible that wet Spectra has less drag than dry Spectra? Or does Mike's stopwatch need a new battery? LL~
Hello
Interesting speed difference, in team race we run a line grouper to make the lines stick together and go faster or was it to stop the bottom line snagging another flyers head as they are 'grouped' together.
It might just be lines are less fuzzy when wet and more streamlined.
Regards Gerald
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I have been referring back to this thread as I am learning about this new fishing line stuff, but the thread keeps moving with more or less activity. It might be more helpful if this were pinned at the top of a forum some where. Either here in the open Forum or any other that it would be appropriate for. I've been tying knots in cotton string that I have a lot of and have that pretty much figured out. Now just waiting for some rings to arrive. There have been many threads on the subject but this one seems to have everything in it that I needed and most likely anyone else also.
Type at you later,
Dan McEntee
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I have been referring back to this thread as I am learning about this new fishing line stuff, but the thread keeps moving with more or less activity. It might be more helpful if this were pinned at the top of a forum some where. Either here in the open Forum or any other that it would be appropriate for. I've been tying knots in cotton string that I have a lot of and have that pretty much figured out. Now just waiting for some rings to arrive. There have been many threads on the subject but this one seems to have everything in it that I needed and most likely anyone else also.
Or, someone designated by Sparky with good writing skills and very acquainted with Spectra, write a pinned starting post concisely summarizing official rules, other rules (including rules of thumb) for use, proper knotting techniques, what strengths best to use for what size / power of aircraft, care, when to replace, lessons learned, things to watch out for, best brands to use, brands not to use, best colors for visibility given the type of flying surface used (grass, dead grass, black top, concrete, hard clay), etc. May be even include a link back to this thread. Then others can chime in to further contribute to it.
Although there is a lot of good in this thread, because this thread has become long requiring gleaning, I think a fresh start thread recapitulating the good spoken here can go a long way toward a good pinned thread. We are already on Page 6 of this thread, hence my comment.
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I don't use Spectra-type lines in CL, but I think what I do with them is much more violent and stressing to the line.
Wetting is not necessary, there is no "aligning of fibres" necessary. That's all just homeopathy.
Actually, the wetting can be counter-productive aster will be water between the fibres, not allowing the braid/knot to fully compress together when tensioned. Don't underestimate the power of capillary forces.
The most important is to increase the tension slowly close to breaking point. If you pull it tight too quick, the line will break from knot due to friction heat, wet or not.
I pull my 150- and 200 pound lines slowly to about 30kp tension and keep the tension for 30 seconds. Repeat 3 times. Then the line is ready to use but still requires some running-in use, to get rid of the square or flat cross section.
Also, when prepared well, the new higher modulus lines mostly break right next to knot, due to hard point fatigue. To fix this, I make a fillet/stiffener from contact cement next to knot, to stiffen the line a little. L
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Also, when prepared well, the new higher modulus lines mostly break right next to knot, due to hard point fatigue. To fix this, I make a fillet/stiffener from contact cement next to knot, to stiffen the line a little. L
What prompted that question was the need to wet the knot before tightening it. I use a double Palomar vs the Uni because I know how to make it exactly where I want it. While the knots are still damp I stretch them the same way you do. Three, maybe four pulls till I sense no stretch left. I will have to try the contact (rubber) cement idea. Rubber cement will move the stress point away from the knot and not restrict it's movement under stress. I am reluctant to put anything that makes a chemical bond on them. I think it is crazy to use CA. I have considered using heat shrink over the knot but didn't. I have seen some trim the knot to near flush. Why would you do that? I don't trim them till they are fully stretched then leave the free line end at least 1/4" long.
Ken
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I have been using Powerpro Spectra lines for almost 3 years now. I don't understand all the concern with the knots, how to tie them, wet them or not, etc. And have used 65# test Spectra lines on models weighing from 30-62 ounces. And passed pull tests with no issues.
Dennis posted a great video on how to tie the knots. I have followed the basics outlined in the video and 'never-ever' had a knot come loose. When completing the knot, just ensure all terminations are pulled tight. The video also shows how to tighten up the knot. Also, when cutting off the loose material, I don't cut right up against the knot. I leave maybe 1/2" of exposed line.
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I have been using Powerpro Spectra lines for almost 3 years now. I don't understand all the concern with the knots, how to tie them, wet them or not, etc. And have used 65# test Spectra lines on models weighing from 30-62 ounces. And passed pull tests with no issues.
Dennis posted a great video on how to tie the knots. I have followed the basics outlined in the video and 'never-ever' had a knot come loose. When completing the knot, just ensure all terminations are pulled tight. The video also shows how to tighten up the knot. Also, when cutting off the loose material, I don't cut right up against the knot. I leave maybe 1/2" of exposed line.
Quick query - what benefit does the double loop bring other than making the knot physically bigger? It seems to me to be a worse solution having a single line into a complex stress concentrating knot than one with a similar knot and a single loop? I have no axe to grind either for or against fibre lines, just trying to understand the mechanics of the theory? D>K
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That is a good question. I have not had either the single or double fail. Since I wasn't sure of the answer, I asked "Bing". Here is what Bing said:
"The Double Palomar knot is considered stronger than the single Palomar knot because it has an additional overhand knot that provides extra friction and prevents the knot from slipping. The double Palomar knot is especially useful when fishing with braided lines, which are slippery and require more friction to hold the knot in place 1. The double Palomar knot has been found to have a 15% greater strength than the single Palomar knot. I hope this helps!"
So there it is, 15% more strength when you fly in the rain. Now my personal belief is that they are about equal since the line rarely breaks in the knot. It breaks at the knot. However, the double is a bit larger and looks like it is stronger around that tiny eyelet, and that makes me feel better when 500 hours of my life is going straight down at 50mph 15' from the asphalt.
Ken
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Quick query - what benefit does the double loop bring other than making the knot physically bigger? It seems to me to be a worse solution having a single line into a complex stress concentrating knot than one with a similar knot and a single loop? I have no axe to grind either for or against fibre lines, just trying to understand the mechanics of the theory? D>K
In the video at the beginning of this thread the narrator says he makes a double loop just for the purpose of wear resistance and durability. In the video he mentions he learned this knot from Phil Cartier and Mike Londke, two well known combat flyers, and they are interested in the extra wear resistance and longevity. Most of the stress and wear is going to happen at the connector terminations, so this make sense to me.
Type at you later,
Dan McEntee
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I use this method and use a double loop around the connector. So far been flying them for over a year and a half with no wear at this termination. I do make sure the knot is tight before each flight but have not found any looseness.
Best, DennisT
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The picture of that last knot is a surgeons. Since a surgeons was designed to allow quick switching of fish hooks (they get straightened out allot by fast hitting fish like Bonita) do you loop the ends through an eyelet like you would with a fishhook or just slip the connector into the loop? I am just curious, I will never use this knot.
Ken
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I also use a short piece of surgical tubing on a scissor-type connector (which is also discussed in the video). It works great. And I don't use any type of eyelet. The Spectra double loop is direct on the connector.
The 65# test lines in the pic are about a year old and I normally fly 2x a week, so lots of flights on this particular set of lines. Absolutely no issues to date. (Even on my 'heavy' Vector 40 at 62 ounces).
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The picture of that last knot is a surgeons. Since a surgeons was designed to allow quick switching of fish hooks (they get straightened out allot by fast hitting fish like Bonita) do you loop the ends through an eyelet like you would with a fishhook or just slip the connector into the loop? I am just curious, I will never use this knot.
Ken
Ken, if you are talking about the knot/loop picture I posted above it is not a simple surgeons knot. The knot/loop is made up as discussed in the video.
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Ken, if you are talking about the knot/loop picture I posted above it is not a simple surgeons knot. The knot/loop is made up as discussed in the video.
I was but my question was answered in the picture below. You just loop them through. Just out of curiosity, is it difficult to get the lines equal length with that knot?
Ken
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I was but my question was answered in the picture below. You just loop them through. Just out of curiosity, is it difficult to get the lines equal length with that knot?
Ken
It has not been difficult for me to get equal length lines as I follow the method outlined in the video. I have made up maybe 10 or 12 sets of lines for myself and other flying buddies and I have come up with a good system that works well for me.
1. I lay out my 60' line marker on the ground.
2. On the 1st line, I stretch the line (65# test) to 25 lbs and hold to get some initial stretch. Then I pull the line to 8 lbs and mark the line w/ a felt tip marker at the 60' mark. Then make up the double loop per the video at the mark point.
3. Then I repeat the same sequence for the second line.
My lines come out pretty much equal length, maybe within 1/8" +/-. I compensate at the hard point handle via the handle adjustment feature.
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It has not been difficult for me to get equal length lines as I follow the method outlined in the video. I have made up maybe 10 or 12 sets of lines for myself and other flying buddies and I have come up with a good system that works well for me.
1. I lay out my 60' line marker on the ground.
2. On the 1st line, I stretch the line (65# test) to 25 lbs and hold to get some initial stretch. Then I pull the line to 8 lbs and mark the line w/ a felt tip marker at the 60' mark. Then make up the double loop per the video at the mark point.
3. Then I repeat the same sequence for the second line.
My lines come out pretty much equal length, maybe within 1/8" +/-. I compensate at the hard point handle via the handle adjustment feature.
I think you have a good method. I use 100# yellow line and I don't pre stretch. I cut two lines to 66' and tie an eyelet to each line using the double Palomar knot. Then I hook up the lines to the plane using clips and measure 67' from the CL to the handle with the controls centered. Then I mark with a black felt tip the point where the lines will be connected to the handle clips. Next tie the eyelets to the handle end of the line and hook them up with clips. Test controls to see if I am in the ballpark. Unhook the plane end and reattach the lines to something solid. I am fortunate to have a 100' hallway just outside my Office/Shop with a door at the end. Now I pull the lines to about 60# for 2 minutes. I do that at least three times or until I feel no stretch when I release the pull and I do that with the knots wet. Trim the ends to1/2". Takes less time than wrapping a set of steel lines.
Ken
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It has not been difficult for me to get equal length lines as I follow the method outlined in the video. I have made up maybe 10 or 12 sets of lines for myself and other flying buddies and I have come up with a good system that works well for me.
1. I lay out my 60' line marker on the ground.
2. On the 1st line, I stretch the line (65# test) to 25 lbs and hold to get some initial stretch. Then I pull the line to 8 lbs and mark the line w/ a felt tip marker at the 60' mark. Then make up the double loop per the video at the mark point.
3. Then I repeat the same sequence for the second line.
My lines come out pretty much equal length, maybe within 1/8" +/-. I compensate at the hard point handle via the handle adjustment feature.
Ken, a bit more info on how I make up my lines to get equal length. I don't use a flying model to make up the lines. I make up the lines in my back yard.
I have an eye screw attached to a simple 2x4. The cinder block works as an anchor so I can pull (stretch) without movement.
1. I cut 2 lines maybe 6'-7' longer than the line length I want.
2. I make up a double loop on each line per the knot-tying video and attach to the eye screw with a zip tie.
3. I measure 60' away from the eye screw and mark the length point on the ground.
4. Then as previously stated, I start with one line and pull to 25 lbs and hold to get some initial stretch. (I use a digital fish scale)
5. Then I pull the line directly over the 60' marked point on the ground to 8 lbs and mark location with a felt pen.
6. Then I make up the second double loop per the knot tie video at the felt tip mark point on the line.
7. Then repeat the entire process for the 2nd line.
Lines come out even length.
BTW, the 25# stretch load and 8# length-marking load are somewhat arbitrary. For 65# Spectra, I wanted to stretch the line a bit less than 1/2 the line ultimate strength. The 8# length-marking load is a bit more than the flying load for a reasonably heavy model. Round numbers, a large stunter flying at say 60' and at a 5 sec lap time maybe pulls 10-12 lbs at the handle, or 5-6 lbs on each line in level flight.
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4. Then as previously stated, I start with one line and pull to 25 lbs and hold to get some initial stretch. (I use a digital fish scale)
t.
Being a neophyte musician, I stretch out the lines between two worn brake rotors, tie the first line then pluck and adjust the tension on the second to get the same note on both. Stretch and length come out reasonably equal.
Ara
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Tried a new technique yesterday, ended up with the most accurate lines I have ever made, Spectra or cable.
I was making lines using two spools of line. In the past I have had trouble with accuracy because (I think) each spool of line had a slightly different stretch properties. Thus, when I made up the line then stretched them, the lines would end up (some times substantially) different lengths after stretch.
This time I followed advice given to me by Dick Imhoff a couple years ago but which I had never done (doh!). I made up a single line a little over double the length I wanted for my line set. In this case I was making 63’ lines so I started by making up a single 130’ line. Then I proceeded to do the stretching cycle, that is 50% of line rating, holding it while I counted to 100.
After stretching, I doubled the line over with both tied ends anchored on a single spike and cut the line in half, each line thus being 65’ long. I had another spike 63’ away and used it to mark and tie the second end just like the Mike Stinson video shows. The lines ended up within 1/16”. Finally, I installed the welded rings in the ends, linked the finished lines end to end and again pulled them to 50% load again, this time counting to 50. Note at that stage I was only verifying the integrity of the second set of ends plus tightening up the “Lenny Loops” around the welded rings.
Then I made a second set, same method, same result – as it should be.
The pre-stretch step was easy to incorporate into the process, and would help even when making lines from a single spool. Best of all, the end product is more accurate because the line stretch is already in there!
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Hello
I have made up lines similar to Dennis's method with a loop of line about a foot longer then needed, with both ends made up attach the loose ends together around a tow ball of a car in the driveway and pre-stretch the big loop of line. Then cut one end to get the final length needed with the excess I had added at the start.
Once the first set was made up and I knew the amount of stretch I was getting for a set line lenght and type of line I could then make up additional sets cutting them shorter by the amount of stretch I was getting . This proved a quick way of making up combat lines with a good consistency.
Regards Gerald
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There has been a lot of discussion in this thread about how people are breaking lines at under the specified line strength. Here is some background text and video by Dave Burch, the "Braidman" on how FINS tests their lines:
https://www.finsfishing.com/blogs/the-science-of-fishing-braids/line-strength-test
He shows how they test and rate their lines and notes that the average break strength is typically much higher than the rating. He then states that with knots the lines will break some 30% lower load than tested - depending on the knot used and skill in tying that knot.
Personally I have gotten over the strength issue - I routinely pull test my lines at a load roughly double the expected pull test before they ever make it to the field so I know the lines are capable before they ever make it into the air.
This video answers the question on how they test the line, but I have been doing some test on line I have ,( mainly testing eyelets to see if they could be used in place of welded rings, which are hard to find) and have been having line break. I start with about a foot and a half of line, ( which has been Hyper Braid by Bass Pro and Spectra Power Pro ) and did the modified surgeons knot and loop on each end. I anchored one end to a wire loop around a fence post and was just going to pull up to 50 pounds and see how the eyelet help up. The eyelet was attached with the loop just like in the video at the beginning of the thread. I stated with 65 pound Hyper Braid, and progressed through 65 and 80 pound Power Pro Slick V-2, some new stuff out. Each time I got to the 30 pound range, pulling slowly and evenly, and the line broke right in the middle. No problems with the knots or loops slipping. I just figured that the test rating was established some other way and was based on longer line lengths or some other engineering factor. Any ideas among you other more experienced users and engineering types?
I have made up a couple sets of lines to try flying with the fishing line on sport models and such. After practicing the knot and loop in the video on cotton string, it was time for the real deal. Mark Hughes and I made up three sets of lone total. one for him and two for me. I think the surgeon knot and loop ends are the best way to go. It's amazing how fast you can make up a set of lines. I think we made the three we did in about 45 minute to an hour and not rushing anything, taking out time and making sure things were right. We finally got a decent day to test fly. I flew my Fox.35 powered rehab Ringmaster that weighs 31 or 32 ounces first. I made those lines from 30 pound test Power Pro. We pull tested the lines to 25 or 30 pounds first, then a few more pulls at about half that to stretch then and held them there. A 10G pull test for this airplane is 20 pounds. I flew two flights with the existing steel lines to really observe how they felt and what the bow in the line was. Then I switched to the Power Pro lines, and I have to say I was impressed. the line still bows but about half as much. I think this line actually measured .012" or .013". It felt pretty good in flight and I can't say if I felt any stretch or not. in fact, I think the model was a little more sensitive due to less slack in the lines, but I'm not going to change anything and fly it a lot more. I noticed the wing drops more after engine shut down so I can probably remove some tip weight. Weather has prevented us from getting back out for more flying and trying the other lines out on a Nobler. But all in all, I have to say that the modified surgeon's knot and looped ends with the welded rings on each end has impressed me. I'll be using the fishing lone for my most flown models that the lines get more use and abuse and take advantage of the durability of the fishing line. We made a set of lines for Mark's Imitation, and he is still unsure, but did not have a bad experience or opinion, just needs to fly it more , but he did think that the model was a bit more sensitive also. Not sure when we will get out again but I'm leaving the fishing line on the Ringmaster and making up some more lines for the other two Ringmasters I have.
Type at you later,
Dan McEntee
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Dan,
I did a test on eyelet ends. check posts 29-31'
Tom
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Dan,
I did a test on eyelet ends. check posts 29-31'
Tom
Thanks Tom ! I didn't terminate mine like that, I looped it like they do with the welded ring. It didn't elongate, but the spot where the loop cinched closed a bit. Looks like your elongated?? I'll just scratch this off as not useable and keep a watch on the sources for welded rings and get a few more bags to have on hand. I got the welded rings Dennis got from Tackle Direct and it didn't look like they typically keep a huge amount on hand! I just feel better about terminating on a ring so I can change line connectors quicker and easier. If the connection at the connector is pretty tight, working those loose enough to remove it seems tricky without nicking the fibers in the line and I don't want t hat!
Type at you later,
Dan McEntee
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So how do you keep your lines on the ground when the wind is blowing? Any wind at all and my lines get blown around and worse, whenever a plane lands and rolls over the lines, which is like every time, they catch on tailwheels. Just for reference, spectra lines stick when you get 20 or so wraps in them. - don't ask how I know.
Ken
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So how do you keep your lines on the ground when the wind is blowing? Any wind at all and my lines get blown around and worse, whenever a plane lands and rolls over the lines, which is like every time, they catch on tailwheels. Just for reference, spectra lines stick when you get 20 or so wraps in them. - don't ask how I know.
Ken
You need to weight down the handle with something significant, after you weight down the end near the lead outs. Bean bags made from heavy vinyl with some lead shot may be helpful here. That may be one drawback to using the fishing lines, they do blow around in the wind, and you have troubles with the old trick of just pulling the model off the circle after a flight to save some walking.
Ty[e at you later,
Dan McEntee
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Hello Yes Spectra lines can be tricky when there is a lot of wind when winding in or out but when on grass will normally sit there without moving. Another problem I have had is twigs or even tree bark getting tangled up in the lines and if your really unlucky you get a birds nest of line. I normally wind them up onto the handle , as long as you unwind them opposite way there will be no twists and you can have them out of harms way very quickly.
Regards Gerald
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Hello Yes Spectra lines can be tricky when there is a lot of wind when winding in or out but when on grass will normally sit there without moving. Another problem I have had is twigs or even tree bark getting tangled up in the lines and if your really unlucky you get a birds nest of line. I normally wind them up onto the handle , as long as you unwind them opposite way there will be no twists and you can have them out of harms way very quickly.
Regards Gerald
LL~ LL~ LL~
I've had the birds nest! - Fired the bird.
One thing I noticed from my latest "adventure" was the difference in how a set of Spectra lines reacts to twists. The spectra lines don't unwrap as easily as metal. I don't do the "unwrap loops" at the end of a flight, perhaps I should. I forgot to unwrap them and had some difficulty getting to the handle on the next flight with the timer running and in haste spun it the wrong way. Ended up with about 10 wraps when the 10 second warning light came on. Barely got the thong on in time. Now before you waste time on the 5-10 things I did wrong here - I KNOW!
So, the plane lifts off and wants to hunt - like elephants. It calms down and I fly out a very sloppy pattern where I couldn't lock out of any corners. So, here is what I learned from avoiding disaster at least three times by being stupid. Spectra lines do not slide over each other as well as metal lines. With the 1-3 wraps during a pattern it is fine but at 10 it is not fine. The old trick of just spreading the lines and letting the handle spin to unwrap them doesn't work very well if you have more than a couple wraps and finally, put your plane at the end of the line so that your lines are far back from the blast from the other guys taking off and keep the lines tight so they don't blow into the next zip code.
Three lessons learned in one day and the miracle is that I still have the plane! Will I now go back to metal - LL~
Ken
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I have two questions. First, I flew a plane yesterday that has been in good trim for about two years on spectra for the first time. It is a full 63" 56oz electric profile. I was flying on Ukraine .0175 lines before the switch to 85lb PowerPro.
I experienced a rather pronounced inboard yaw on corners. I expected the opposite since the spectra are both thinner and lighter and was prepared to adjust tip weight. Is this the expected result for lighter lines? It was very humid. Is it possible that Spectra lines vary in weight more with humidity than metal lines? My first trim movement was to move the leadouts back 1/8" to increase overall tension and that helped. Also raises my lap time from 5.7 to 5.4 (my normal is 5.5). That helped but the yaw was still there, just not as pronounced. I suspect less tip weight and perhaps another 1/8 back on the leadouts. Correcting for yaw has always given me a brain twist! HB~>
Second question that relates to another thread in action right now. So spectra lines offer any protection from static electricity? I feel that they do not.
Ken
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I have two questions. First, I flew a plane yesterday that has been in good trim for about two years on spectra for the first time. It is a full 63" 56oz electric profile. I was flying on Ukraine .0175 lines before the switch to 85lb PowerPro.
I experienced a rather pronounced inboard yaw on corners. I expected the opposite since the spectra are both thinner and lighter and was prepared to adjust tip weight. Is this the expected result for lighter lines? It was very humid. Is it possible that Spectra lines vary in weight more with humidity than metal lines? My first trim movement was to move the leadouts back 1/8" to increase overall tension and that helped. Also raises my lap time from 5.7 to 5.4 (my normal is 5.5). That helped but the yaw was still there, just not as pronounced. I suspect less tip weight and perhaps another 1/8 back on the leadouts. Correcting for yaw has always given me a brain twist! HB~>
Second question that relates to another thread in action right now. So spectra lines offer any protection from static electricity? I feel that they do not.
Ken
Hi Ken
Yaw trim is.... challenging! I do not think this is a Spectra thing, but I have recently rediscovered the importance of just a tick of rudder offset. The purpose of the offset is not so much to add line tension but rather to stabilize the airplane in yaw. Last airplane I this was on the MoBest where after a level flight pull out it would wobble side to side for a 1/4 lap or so. A very small movable rudder was added with only 1/8" offset to cure that problem. Did seem to help some on the upwind side of the Overhead Eight.
As for tip weight, I observed a condition like you described when I put a Pathfinder on Spectra; it looked like the outboard tip was spiraling down & around then out of the corner, ending with an inboard yaw - improved via weight removal. I suggest a flight session where you start removing a small dollop (1/4 oz or so) per flight until you start sensing that you gone to far! Then add some back: if you are anal about it add back a little less than the last amount that you remove and really fine tune what you need. Again I did that with the Mo'Best last year. Ended up removing about 11 grams.
For me the anal part was that instead of clipping corners off a 1/4 tip weight slug, I used (wait for it) ALUMINUM tip weight slugs, about 1 gram apiece to fine tune tip ballast..!
EDIT: added italicized phrase in 2nd paragraph
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Second question that relates to another thread in action right now. So spectra lines offer any protection from static electricity? I feel that they do not.
Ken
Missed your Q2. I suspect you are right but am uncertain HOW to prove it. After getting static shocks routinely (i.e., flying in Rouge Park into twilight hours in the summer) when flying with an EZ-just, I used other handles that did not discharge the static into my hands - have not experienced a static shock in over 50 years.
I do not really understand the mechanism by which lines pick up a static charge but it does not seem that Spectra or any other line material would be completely immune to gathering static charge nor whether they would be better or worse than SS cables.
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I wouldn’t think it would conduct much voltage.
Maybe attach two lines to a DC power supply and measure the output?
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Hi Ken
Yaw trim is.... challenging!
No kidding! Now that you mention it, I think the plane was fishtailing where it should have been locking. I blew that off as crappy piloting having not flown in a month or so. Thanks for giving me an excuse to blame the plane! Next time out I will divest it of some tip weight and add a few RPM's to keep the lines tight. Funny you should mention rudder. It has a cam for just the reason you stated. Best whisper (shhh), because admitting to using rudder might get you cancelled. n1
I was quite proud of how this profile flies. It appears to fly like a real PA, but after a few months flying the canard, I was shocked at the difference in turning. My first pullout on the RWO caused several worms to have heart attacks.
Ken
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No kidding! Now that you mention it, I think the plane was fishtailing where it should have been locking. I blew that off as crappy piloting having not flown in a month or so. Thanks for giving me an excuse to blame the plane! Next time out I will divest it of some tip weight and add a few RPM's to keep the lines tight. Funny you should mention rudder. It has a cam for just the reason you stated. Best whisper (shhh), because admitting to using rudder might get you cancelled. n1
I was quite proud of how this profile flies. It appears to fly like a real PA, but after a few months flying the canard, I was shocked at the difference in turning. My first pullout on the RWO caused several worms to have heart attacks.
Ken
Ken
Switching to Spectra of course required at least a little re-trimming on existing airplanes. Not stopping there, whenever I pick up something haven't flown for awhile I end up with some kind of trim tweak to get a little better feel, a little better performance. Works both ways too; go back to the main bird and as often as not I'll get another idea to try to squeeze a little more out of it too!
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Used my 100# dark green Spectra to lash the brass hinge barrels to the elevator of a well used, unknown combat plane destined for Brodaks. It looks suspiciously like Phil's Rugged Stunt Trainer modified from its former life to fly combat.
Ara