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Author Topic: Flying Lines Crimp Tubes  (Read 1812 times)

Offline Phillip Kenney

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Flying Lines Crimp Tubes
« on: July 18, 2021, 10:58:54 AM »
Two questions. First what size tube do I use for  .015 lines? And where can I get them, other than RSM who wants $11.95 for shipping?

Offline Donald Main

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Re: Flying Lines Crimp Tubes
« Reply #1 on: July 18, 2021, 11:07:59 AM »
You can wrap the lines with fine copper wire, fold the .015 wire and back wrap them. This works quite well.

Offline Dave_Trible

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Re: Flying Lines Crimp Tubes
« Reply #2 on: July 18, 2021, 11:10:48 AM »
I think the best answer is just don't.   After having too many strands in the line break right where they come out of these tubes I stopped doing that and simply wrap with fine copper wire and put a little epoxy on the wraps to keep them together.  If you have to use the tubing it can be had at most Westake-Ace hardware stores where they have a K&S rack.  1/16" aluminum or copper tubing can be found there and sawn into piece length.

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Offline Phillip Kenney

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Re: Flying Lines Crimp Tubes
« Reply #3 on: July 18, 2021, 02:28:54 PM »
Ok, since the concensus is to not crimp but to wrap the lines, what size and where do I easily get the wire to use for wrapping?

Offline Dave_Trible

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Re: Flying Lines Crimp Tubes
« Reply #4 on: July 18, 2021, 02:46:32 PM »
I get it from Jim at Lee Machine Shop.  The spool I have says .013 but it mics at .0125...

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Offline Peter in Fairfax, VA

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Re: Flying Lines Crimp Tubes
« Reply #5 on: July 18, 2021, 03:45:38 PM »
I wrap my lines, but do not solder or epoxy the result.  The reason I don't use solder/epoxy is that I want the whole assembly to flex, and not have a stress point that might fatigue.

Offline peabody

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Re: Flying Lines Crimp Tubes
« Reply #6 on: July 18, 2021, 03:55:42 PM »
The "Russian" 3 strand lines are crimped.
The controls of a Cessna 172 are crimped

Offline bill bischoff

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Re: Flying Lines Crimp Tubes
« Reply #7 on: July 18, 2021, 04:29:24 PM »
The controls of a Cessna 172 are NOT crimped, they are swaged. Swaged cable connections actually squeeze the metal of the soft(er) swaging sleeves around and in between the strands of the cable. Crimped line connections are more akin to cable clamps than swages. But if you want to fly with Cessna control cables, I'm sure they won't break.

I use wrapping wire for tying fishing flies when I make lines. It is available in different colors fore easy line ID. I use the biggest size wire they sell at Bass Pro Shops, which is "BR" or "brassie". I don't know what that actually means, but the other sizes are so small I'd be afraid they might break during the normal wrapping process. The tools used to hold the wire during the wrapping process are called bobbins. They are also quite handy for line wrapping.

I may occasionally used crimped terminations on combat lines, which have a short life expectancy.

Offline Gary Dowler

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Re: Flying Lines Crimp Tubes
« Reply #8 on: July 18, 2021, 05:43:36 PM »
Lee Machine shop sells a nifty line wrapping tool for a good price. It comes preloaded with copper wire, enough to do at least 10-12 sets of leadouts.   Wrapping is superior to crimping.

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Offline Steve Helmick

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Re: Flying Lines Crimp Tubes
« Reply #9 on: July 18, 2021, 06:26:16 PM »
I wrap mine with copper wire per the AMA rulebook, and cover the wrap with two (telescoping) sizes of shrink tubing. The idea is to move the stress point away from the wrapping.

FWIW, I know guys that color code their lines & leadouts, but I know of at least one crash due to trusting the color coding. I'd rather not be misled, so use just one color of shrink tube. But you do what you want to do, while it's still allowed!  y1 Steve

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Offline Chad Hill

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Re: Flying Lines Crimp Tubes
« Reply #10 on: July 18, 2021, 09:26:42 PM »
FWIW, I've been crimping lines (.018) for years and never had a problem.

Offline Reptoid

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Re: Flying Lines Crimp Tubes
« Reply #11 on: July 18, 2021, 11:05:09 PM »
If crimps are done properly, they will never fail before the line does. Use deburred crimp sleeves and don't smash the ends. Follow the double loop AMA legal example in the AMA Rulebook. Only use soft copper; not brass or steel. You can get crimp sleeves, eyelets and bulk line from MBS Model supply. Great people, great prices, and reasonable shipping

http://mbsmodelsupply.com/Catalog.pdf
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       Don
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Offline Ken Culbertson

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Re: Flying Lines Crimp Tubes
« Reply #12 on: July 19, 2021, 05:58:22 AM »
I wrap mine with copper wire per the AMA rulebook, and cover the wrap with two (telescoping) sizes of shrink tubing. The idea is to move the stress point away from the wrapping.

FWIW, I know guys that color code their lines & leadouts, but I know of at least one crash due to trusting the color coding. I'd rather not be misled, so use just one color of shrink tube. But you do what you want to do, while it's still allowed!  y1 Steve
For my vote/2cents, whatever, I am with Steve on this one.  Only lines I have ever had fail (in a pull test - whew) were crimped.  Either will probably work just fine but wrapped and heat shrinked look better.  Long as the eyelet is free to move and the line will only tighten, I am fine.  Crimped on a bell crank has always made me nervous, especially when it is not floating.

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Offline Dan McEntee

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Re: Flying Lines Crimp Tubes
« Reply #13 on: July 19, 2021, 06:50:41 AM »
    I have lost three models due t crimped lines breaking at the crimp near the handle. These were factory made Sullivan lines on all three. In my dealings over the years I have accumulated a lot of line sets that were brand new, so I examined them carefully and used them.  The lines all broken right where the crimp was in the copper tube with no warning or signs of fraying. If the factory can't do it correctly, I don't think I don't think I want to go through the learning curve!! Now  if I go to use a set of older N.O.S. lines, I re-wrap the ends first.
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   Dan McEntee
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Offline Perry Rose

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Re: Flying Lines Crimp Tubes
« Reply #14 on: July 19, 2021, 07:17:17 AM »
Until I had the chance to buy copper wire first from Tom Morris and then Jim Lee I used Lamp cord or speaker wire stripped and untwisted. No problems using either wire.
I may be wrong but I doubt it.
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Offline Leonard Bourel

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Re: Flying Lines Crimp Tubes
« Reply #15 on: July 19, 2021, 08:05:35 AM »
The only planes I fly on crimped lines are the junk planes Old sport planes etc

Offline John Paris

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Re: Flying Lines Crimp Tubes
« Reply #16 on: July 19, 2021, 10:13:09 AM »
The only planes I fly on crimped lines are the junk planes Old sport planes etc

Come on Len, I have seen you fly some of your 80+ ounce beasts on crimped Spectra...... n~
John Paris
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Offline John Park

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Re: Flying Lines Crimp Tubes
« Reply #17 on: July 19, 2021, 12:46:11 PM »
FWIW, I know guys that color code their lines & leadouts, but I know of at least one crash due to trusting the color coding. I'd rather not be misled, so use just one color of shrink tube. But you do what you want to do, while it's still allowed!  y1 Steve
Slightly off-topic, I always colour code my line ends, but couldn't work out a good way to do this with the Spectra lines I've switched to for sport flying.  Then I realised: buy one spool of hi-viz yellow, and one spool of red - same make, same specification, just different colours.  Red for the up line, yellow for down.  Not all my models have the 'down' leadout at the front, so it's as well to colour-code the leadouts to match (ask me how I know!).
You want to make 'em nice, else you get mad lookin' at 'em!

Offline mike londke

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Re: Flying Lines Crimp Tubes
« Reply #18 on: July 19, 2021, 01:18:30 PM »
FWIW, I've been crimping lines (.018) for years and never had a problem.
Amen brother. Been using only crimped lines on Nelson .36 Fast Combat planes and never had one fail. If they can handle the pull of a 130mph plane I'm pretty sure if crimped properly they'll hold up to any stunt ship S?P S?P
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Online Brett Buck

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Re: Flying Lines Crimp Tubes
« Reply #19 on: July 19, 2021, 01:24:04 PM »
Amen brother. Been using only crimped lines on Nelson .36 Fast Combat planes and never had one fail. If they can handle the pull of a 130mph plane I'm pretty sure if crimped properly they'll hold up to any stunt ship S?P S?P

  It is not a matter of how strong they are in terms of absolute load, it is the fact that they tend to cause failure from fatigue of the line where it is forced to flex around the edges of the crimp, That's why it doesn't matter whether it is "crimped" or "swaged", the strength of the connection the day you do it is far more than sufficient, it's the damage down the road that causes the problem. It's not a problem for static cables that are not flexed (like aircraft control cables and telephone pole guy wires) but we flex the lines repeatedly right at the edges of the crimp putting them on and off.

     Brett


Offline Dan McEntee

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Re: Flying Lines Crimp Tubes
« Reply #21 on: July 19, 2021, 03:30:19 PM »
Amen brother. Been using only crimped lines on Nelson .36 Fast Combat planes and never had one fail. If they can handle the pull of a 130mph plane I'm pretty sure if crimped properly they'll hold up to any stunt ship S?P S?P

   For combat, you guys may only get a couple of contests out of a set of lines before they just get all boogered up in line tangles and such and you toss them anyway.  Combat is way harder on lines than stunt. If I was flying combat competitively I would probably use crimped lines also because it's just faster to make up lines that way. My experience was losing three models to factory crimped lines breaking at the crimp. You could look inside the tube and see the frayed ends sticking out from where the crimp was. Like Brett said, it's the repetitive flexing at that point that work hardens the cable and then it snaps. My flying buddy just lost a model right before the NATS when a handle cable broke for the same reason, flexing right where the cable entered the handle. The cable was that stuff with the green plastic coating that Windy and some of the other vendors used to sell, and the plastic coating hid the fraying so he never saw it, and when the cable broke it was like it was cut with a set of side cutters. Think about how many times and how far you flex that cable in ONE pattern flight!  Now multiply that by number of contest flights plus practice flights and you get the picture. Stunt grunts tend to take care of their stuff and some of us are cheap (read THRIFTY) old bastards and we try to get as many miles out of our stuff as we can so we go way longer on a set of lines or handle cables that most. Flying lines and handle cables should be changed out frequently but old habits are hard to break, or get over I should say! The key is to inspect and check lines and handles every time you fly.
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Offline Leonard Bourel

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Re: Flying Lines Crimp Tubes
« Reply #22 on: July 19, 2021, 04:12:59 PM »
Hey  John Maybe you are thinking of someone else or maybe the script on those glasses of yours needs an update  HA HA LL~

Offline Reptoid

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Re: Flying Lines Crimp Tubes
« Reply #23 on: July 19, 2021, 11:10:03 PM »
     Say what you want about Combat fliers and their lines but here's my observations. I fly combat planes at least two days every week. I fly stunt and sport  planes with a group of stun/sport fliers 1 day every week. In the last year I have seen 3 stunt planes lost to line failure; one set wrapped and two sets crimp sleeves. None of them failed at the end due to wire breakage. One failed near the handle at a previous kink. One failed due to poorly assembled end pulling through the sleeve (single pass through sleeve and bad crimp). The third failed mid line at a frayed spot with previously broken strand. Average number of stunt flyers on Sat/Sun is 4-8.
      In that same year I have seen zero line breakage at the combat field. Average number of combat flyers on Sat/Sun is 5-8
Here's my opinion on why the difference:
      Combat flyers are very aware of the condition of their lines and inspect them every time they fly. At contests FAI ships are pulled 45lbs and measured (dia. and length) before every flight. AMA planes are pulled 35lbs prior to every flight and measured. We walk our lines out after every flight. If we have a kink or broken strand we immediately throw them away.
     On the other hand, I see very different behavior on the sport/stunt side. I see people trying to fly with lines I would have thrown away long ago. I see people putting a sharp kink in the line right at the termination when they store their lines on a reel. I see cheap people not replacing lines to save a buck (false economy). I see lines being dragged across rough pavement and snagged on weeds etc.
     It really doesn't cost much to have decent lines and care for them. At most a premade set of really nice lines can be had for less than $25 if you absolutely can't make your own. If you make your own and buy the materials from MBS you can make a set of 60 footers for under $6.00
    Either method works but both require proper assembly and some due diligence inspecting and maintaining them.
Regards,
       Don
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Offline Mike Griffin

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Re: Flying Lines Crimp Tubes
« Reply #24 on: July 20, 2021, 08:22:07 PM »
Phillip I use copper wire that I buy from McMaster-Carr for wrapping.  It is .028 guage. 

Mike

Online Brett Buck

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Re: Flying Lines Crimp Tubes
« Reply #25 on: July 21, 2021, 12:06:30 AM »
Phillip I use copper wire that I buy from McMaster-Carr for wrapping.  It is .028 guage. 

Mike

     I think you mean 28 AWG, not .028 (way too thick). 28 AWG is .0126 (bare). That would be OK for leadouts.

      For lines I use 30 or 32 gauge magnet wire (insulated). I have it for other reasons, but it works very well, is flexible enough to avoid the stress concentration issue, and with the insulation, you can wrap it and then dip it in acetone, and while this will not take off the insulation, but soften it just enough to make it stick together.

   Even though it appears we will be getting rid of the psuedo-required-construcion part of the line requirements, the wrapping method shown in the AMA rule book is pretty much bulletproof and I follow it more-or-less to the letter.

   BTW, on the topic of crimped tubes, I have never used the AMA method precisely. In fact I expect it was put in there just to allow pre-made lines from Pylon and others. I did not loop the second pass of the "free" end of the line through inside, I always looped it around the outside, because that's what my dad told me to do. That always seemed a lot safer and I have seen *many* factory crimps made like the AMA rulebook method fail by having the free end pull out. Loop it around the outside, and it has a loop that pulls tighter if the crimp slips.

     I never had a problem with the crimps failing or pulling apart on my own line terminations. I did have repeated issues with the wire fraying right at the end of the crimp tube, usually at the eyelet side, and have never had that happen with wrapped lines.

      Brett

   

     

Offline Mike Griffin

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Re: Flying Lines Crimp Tubes
« Reply #26 on: July 21, 2021, 10:00:09 AM »
     I think you mean 28 AWG, not .028 (way too thick). 28 AWG is .0126 (bare). That would be OK for leadouts.

      For lines I use 30 or 32 gauge magnet wire (insulated). I have it for other reasons, but it works very well, is flexible enough to avoid the stress concentration issue, and with the insulation, you can wrap it and then dip it in acetone, and while this will not take off the insulation, but soften it just enough to make it stick together.

   Even though it appears we will be getting rid of the psuedo-required-construcion part of the line requirements, the wrapping method shown in the AMA rule book is pretty much bulletproof and I follow it more-or-less to the letter.

   BTW, on the topic of crimped tubes, I have never used the AMA method precisely. In fact I expect it was put in there just to allow pre-made lines from Pylon and others. I did not loop the second pass of the "free" end of the line through inside, I always looped it around the outside, because that's what my dad told me to do. That always seemed a lot safer and I have seen *many* factory crimps made like the AMA rulebook method fail by having the free end pull out. Loop it around the outside, and it has a loop that pulls tighter if the crimp slips.

     I never had a problem with the crimps failing or pulling apart on my own line terminations. I did have repeated issues with the wire fraying right at the end of the crimp tube, usually at the eyelet side, and have never had that happen with wrapped lines.

      Brett

Thanks for catching the error Brett.  You are correct.

Mike

   

   

Offline Mike Griffin

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Re: Flying Lines Crimp Tubes
« Reply #27 on: July 21, 2021, 10:03:27 AM »
Phillip,

Thanks to Brett for catching my error.  The copper wire I use is 28 AWG for leadouts.  Just had a senior moment brain fart.

Mike

Offline phil c

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Re: Flying Lines Crimp Tubes
« Reply #28 on: July 22, 2021, 05:14:37 PM »
FWIW, I've been crimping lines (.018) for years and never had a problem.

Home Depot and others sell inexpensive electrician combo cutting/crimping/swaging pliers.  They're a bit awkward to use but d a decent swage down to about 18 gauge tubing.
phil Cartier

Offline phil c

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Re: Flying Lines Crimp Tubes
« Reply #29 on: July 22, 2021, 05:21:54 PM »
  It is not a matter of how strong they are in terms of absolute load, it is the fact that they tend to cause failure from fatigue of the line where it is forced to flex around the edges of the crimp, That's why it doesn't matter whether it is "crimped" or "swaged", the strength of the connection the day you do it is far more than sufficient, it's the damage down the road that causes the problem. It's not a problem for static cables that are not flexed (like aircraft control cables and telephone pole guy wires) but we flex the lines repeatedly right at the edges of the crimp putting them on and off.

     Brett
Whenever I make up a set of crimped line for a stunt plant I use small guage  shrink tubing that extends ~1/8th in onto the loop and half an inch onto the flying line.  It makes fatigue from bending hard, if not impossible to do.
phil Cartier


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