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Building Tips and technical articles. => Building techniques => Topic started by: Jim Thomerson on January 05, 2012, 01:45:08 PM
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I probably posted these some time back and just don't remember. The adjustable leadouts are above the wing in this model. This may help someone clueless about it all.
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Nice job, Jim! These pictures should answer a lot of questions.
BIG Bear
RNMM/AMM
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I probably posted these some time back and just don't remember. The adjustable leadouts are above the wing in this model. This may help someone clueless about it all.
Jim,
Great photos, I'm sure the clueless will be thankful.
Gotta tell ya, I had no idea what they were referring to until I saw a photo. n~
Now I'm installing one, and designing one that may a better! Well, different anyway.
CB
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What material for the tubes?
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The tubes are like the little yellow externally ridged tubes that come with Perfect leadout sets. They are also the inner tube in the pushrod snakes used in RC airplanes. They need to stick out a little to the outside to keep the slider oriented in the track. The track is glued up out of hardwood strips rather than being cut out of ply.
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" and designing one that may a better! Well, different anyway. "
Do share the concept with us... there are only certain permutations of leadout design anything new / different would be interesting to see.
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" and designing one that may a better! Well, different anyway. "
Do share the concept with us... there are only certain permutations of leadout design anything new / different would be interesting to see.
PJ,
I don't know, all these smart know it all's one would thing a design chang would have been done long ago.
Like just learning about automotive paint systems, where have you been?
CB
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Guess I need to take pictures of the adjustable guide construction on my next plane. H^^
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Guess I need to take pictures of the adjustable guide construction on my next plane. H^^
John,
What are you using? What is your next plane?
CB
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i like it looks pretty simple to me .thanks for pix #^ rd
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Jim -- thanks for posting those pics. I'm building a Ringmaster S-1 right now, and I was sorta stuck on what I wanted to do for a leadout guide.
I now have one that looks an awful lot like yours, except I'm using brass tubing instead of plastic.
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Nice leadout assembly for when it needs to be above the wing
Tim, are you mounting your leadouts above the wing on a RM S-1???
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Tim, are you mounting your leadouts above the wing on a RM S-1???
Eww, ick.
No, I'm just copying Jim's carrier and putting it in the normal place at the center of the airfoil. Jim's picture helped because when I get to steps like this in the build sequence part of my brain tends to run away with me, coming up with all sorts of elaborate schemes (should I mill it out of aluminum with brass bushings? All brass and damn the weight? PTFE and use a sheet metal screw? Etc.). Jim's nice and simple carrier pushed me out of analysis paralysis very nicely, even if I did go through two iterations of the carrier trying to find the World's Best Way to make this out of plywood.
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LOL,,, whew,,
ya had me worried man,,
one thing, I would reccomend the nyrod inserts instead of brass, personal preference, smoother and less wear on the leadout cables,,
I to suffer from * overengineeritiss and it would be so cool to do it this way cause,,,,,,
Thats why I keep Pat J on speed dial, he always starts off with,," thats a really cool idea, and it wont take but 300% longer than doing it "this" way that works just fine,,"
and I say, "yeah but,, but,, sigh, Ok Pat your right"
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The reason I used brass was concern about wearing the guides -- this is not a problem with nylon? It seems like continual use would saw little slits in the nylon, and then the leadouts would get jammed.
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I have not ever seen it be a problem, its kind of self lubing, I would be more concerned about wear in the brass myself,,
others may have more LONG term experience than me, but I dont seen a problem
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The reason I used brass was concern about wearing the guides -- this is not a problem with nylon? It seems like continual use would saw little slits in the nylon, and then the lead-outs would get jammed.
and for the record,, just how long do you expect your RM to live anyway,, 100 flights,, 500 flights? pretty sure wear is on the lead-outs wont be what ultimately grounds this plane,, ;) just sayin,,
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I've never had a wear problem. Perhaps a wear problem would indicate that the guide was not in the proper position.
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and for the record,, just how long do you expect your RM to live anyway,, 100 flights,, 500 flights? pretty sure wear is on the lead-outs wont be what ultimately grounds this plane,, ;) just sayin,,
Oh, details!!!.
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Tim, as you recall, I was not long ago where you are now,, ( with flying skill and experience) so I first off understand the logic of profile airplanes and easily repaired ones at that,, so my comment is that perhaps, the demise of this airframe as an airworthy example may be the result of unfounded bravery at the handle as opposed to a mechanical failing of the leadout guides after some several hundred flights,,
now that doesn't mean I EXPECT you to crash, but, well, remember I was there too,, as were we all,, >:D ;D Hence the premise of building something simple, and several of them, then fly till you run out of airframes,, rebuild and repeat,, LOL
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Here's mine. I think Tom Morris showed it first when he was Stunt News editor. Two pieces of 1/16" ply, 1/8" ply slider and pop rivets with the mandrels knocked out.
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I use brass tubes for leadouts (because that's what Paul Walker uses: that's how I "design"). They last a long time. Thereby hangs a tale. One local guy decided to add a spare leadout guide tube on each leadout, so he could replace a worn-out tube without unwrapping the end of the cable. He discontinued the practice, maybe because alarmed launchers hesitated to let go of the airplane when they saw the loose tubes.
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Hey Tim,,
what Howard said,,
My overthinking overthought my thinking again,, if it works for Paul and Howard, their airplanes get LOTS more flights than mine survive,,
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and for the record,, just how long do you expect your RM to live anyway,, 100 flights,, 500 flights? pretty sure wear is on the lead-outs wont be what ultimately grounds this plane,, ;) just sayin,,
LL~ LL~ LL~
Thinking the same thing after i read this.....
LL~ LL~ LL~
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I've never had a wear problem. Perhaps a wear problem would indicate that the guide was not in the proper position.
If the aircraft is properly aligned with belcrank, lead-outs, etc., there should be very little load on the lead-outs. The problem arises when the belcrank width does not match the lead-out width. Normally, most of the flight is with the belcrank at or fairly neutral. If the lead-outs are close to each other, the side loads are in effect. The loads are less when the belcrank is at the extremes. At one time, there were rounded belcranks where the lead-out wire just wrapped around it on a slot. The angles were constant... It was an attempt to diminish the exponential control around the neutral... Never saw them again... I believe that unless the angles are extreme, physically, Sullivan Ny-Rod, etc. will last longer that other mechanical systems on the aircraft. I have control systems that are beat up from use in combat over and over again over 20 years, (We save everything for re-use) still good...
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I had a .35 size model (Ramrod) with around 700 flights on it.
The leadouts were 0.027" cable through brass tube guides.
Ater I lost it on a really windy day we dissected it to find that the brass tubes were about 1/3rd worn through.
Due to the oil seepage in the tank bay I highly doubt it would have survived another 700 flights had I not crashed it that day n~
Cheers, Rob.
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I had a .35 size model (Ramrod) with around 700 flights on it.
The leadouts were 0.027" cable through brass tube guides.
Ater I lost it on a really windy day we dissected it to find that the brass tubes were about 1/3rd worn through.
Due to the oil seepage in the tank bay I highly doubt it would have survived another 700 flights had I not crashed it that day n~
Cheers, Rob.
YOU GUYS ARE KILLING ME....
LL~ LL~ LL~ LL~ LL~
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I've never had a wear problem. Perhaps a wear problem would indicate that the guide was not in the proper position.
The yellow part of the nyrods is really tough stuff. I would think you would have a tough time wearing it no matter how far off the leadouts were. Brass isn't very durable at all in this application.
Brett
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Hey guys,
By all means notice the locknut on Geoff Goodworth's adjusting bolt. This will prevent the loss of the slider inside the wing should you turn the adjuster out a little too much. (although I'd tighten it up a bit more, myself). Guess How I learned this trick!
:##
Ward
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I you want to go KISS, then the adjustable system that Dee Rice and Pat Johnston showed me is it!!! I don't believe they invented the system but I do not know who originated it. Two pieces of light plywood are clamped together sandwiching a 1/32'" ply. then appropriate holes are drilled. The portion of the 1/32" piece where the holes were drilled is removed and the remainder is cemented together. This can then be incorporated into the wing tip.
The photo is for a 1/2 A but this can be used for full blown stunters also. The wing tip shown uses 1/8" pop rivets which have the pin pulled out but any appropriate eyelet can be used. To adjust you simply pull the rivet (eyelet) out of the wing tip and move it. You can not only adjust sweep but also the distance between the lead-outs.
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Pop rivets. D'oh. Now I can stop trying to find eyelets.
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I you want to go KISS, then the adjustable system that Dee Rice and Pat Johnston showed me is it!!! I don't believe they invented the system but I do not know who originated it. Two pieces of light plywood are clamped together sandwiching a 1/32'" ply. then appropriate holes are drilled. The portion of the 1/32" piece where the holes were drilled is removed and the remainder is cemented together. This can then be incorporated into the wing tip.
The photo is for a 1/2 A but this can be used for full blown stunters also. The wing tip shown uses 1/8" pop rivets which have the pin pulled out but any appropriate eyelet can be used. To adjust you simply pull the rivet (eyelet) out of the wing tip and move it. You can not only adjust sweep but also the distance between the lead-outs.
That's what I do. After awhile, you gotta tear off a little piece of paper towel and cram it in with the eyelet for a shim. I got this trick from a local guy. I was skeptical, but he has airplanes with thousands of flights on them, and I think he fiddled with the leadout position between most every pair of flights.
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Here is something I may be wrong on, and will post so people can correct me if needs be. It is my unreliable recollection that Lew Mcfarland invented the tube plug in system and Al Rabe invented the slider system. I don't have the skill to build the plug in system neatly enough to suit me, and like the infinite adjustability of the slider system. I don't see the need of separate sliders for each line, but some folks do. Incidentally, on 1/2A I would use one hole for the leadouts as even a 1/2 in separation will cause noticeable yaw in corners.
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I learned about the pop rivets over on SSW. Also the person that showed them had peices of WD-40 tubing in the rivet. I don't use the WD-40 tubing myself as I have not seen that much wear on the pop rivet.
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After awhile, you gotta tear off a little piece of paper towel and cram it in with the eyelet for a shim.
Just a thought: http://www.gaussboys.com/ndfeb-magnets/R0602.html
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For damping?
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Face the hole-and-slot thingie with thin steel, and put a magnet around each rivet head. Then you can make the holes with play from the get-go and not have to worry about them wearing and needing shims to maintain tension.
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Ward, your point is well made however, the nyloc nut is probably only finger tight to show how the system works.
When I complete the installation, I tighten the lock nut—remember it needs a spanner and a hex key—so that there is only just enough free play for the slider to move past the max width point of the ply tip pieces.
I just wish I could get the screws out of the tips of my ARC Vectors so I could fit longer screws with lock nuts behind them.
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Other tricks are to put a little blob of epoxy on the end of the slider bolt, or crimp the bolt with a pair of wire cutters. I had one come loose. Getting it back together was not hard. Just a matter of shaking the slider back in position, then holding it with an L Allen head wrench while starting the new bolt. I have thought about using a nylon bolt, but have not tried it.
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If you use the plywood track/slider setup, be sure to install it solidly and reinforce it with some vertical sticks, like 3/16" square, firm balsa. I adjusted the one on the SV-11 (not a Brodak ARF/ARC) and it flew just horribly. I'd knocked the track loose from the 1/16" soft balsa rib when I loosened or tightened it. Really lucky (or very skilled at flying badly adjusted planes?) not to splatter it...huge line tension and not much of a corner. A lot of level laps and a sore arm resulted, but no splinters. :o Steve
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I've had sliders come loose twice. The first time was a practice flight, and the slider slid to the back of the track. I flew it out level. The other was on the pictured airplane on the second flight at Tucson. The slider stayed in place and I did not know it was loose until I was cleaning up the airplane. :o
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I always made my adjustable leadouts with a row of holes split through the center, with brass eyelets for guides and never had an issue. I have a P40 ARF that has the slider system buried so deep in the wing that I need a flashlight to look in the very narrow slot to even see the binder bolt. A real PIA at the field. I have actually had the leadouts cross in the wingtip. Perhaps designing a thicker tip would allow the slider to be closer to the edge and more accessible.
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I just rebuilt my 1988 Juno that had the brass eyelets that push into holes in the wing tip. The brass eyelets were like new with 1500 flight on them. The leadout wires showed thinning where they went thought the eyelet.
Ed
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I just rebuilt my 1988 Juno that had the brass eyelets that push into holes in the wing tip. The brass eyelets were like new with 1500 flight on them. The leadout wires showed thinning where they went thought the eyelet.
Ed
Ed,
Solid wires?
Charles
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Charles they were flexable leads. They were very smooth and felt thinner. I removed the wing tips and left them hanging so the plane would fit in a storage box 20 years ago. The wing tip was hanging from the wing by the leadout wires.
If you go to this link where I started a thread on building a Juno in 2010 I found the tip block from the 1988 Juno. I had open up the starage box and saw the plane and thought it was my 1979 Comet. I cut the wires off and used the block on the new Juno. The block failed as it was fuel soaked and I crashed the plane but repaird the plane and put a slider it it. Later the wing broke and I got the old Juno out and now have it totaly rebuilt
http://stunthanger.com/smf/index.php?topic=18512.0
Ed
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leadouts.
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My new Bearcat is heavy and pulls very hard. The slider came loose and moved to the back. I put it back to the correct spot but it is moving a little each flight so I made a second short slider to go behind the front one to act as a lock. From now on I will add the second slider during construction. y1
Ed
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My new Bearcat is heavy and pulls very hard. The slider came loose and moved to the back. I put it back to the correct spot but it is moving a little each flight so I made a second short slider to go behind the front one to act as a lock. From now on I will add the second slider during construction. y1Ed
Ed,
I imagine one could glue rough sandpaper to each of the contact sides which could eliminate that sliding.
A possibility?
Charles