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General control line discussion => Open Forum => Topic started by: keith varley on June 14, 2011, 08:16:13 PM
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I like to make my own flap horns , so that I can get the correct geometry. Where can I get a small supply of tweakable 3/32" and 1/8" wire? Music wire just doesn"t do the job.
Keith Varley
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Have you tried welding rod? It's definitely more tweakable than music wire, but you have to buy it in bulk. You may be able to beg some from your friendly local welder.
You can draw steel at kitchen oven temperatures. If you have spare time (and wire) you could try drawing a music wire horn in the oven for 20 minutes at 450, and see how it goes (don't try this with a Sig horn*). Different temperatures and soak times will give you different levels of softening, so you'll kinda be able to choose what you end up with**.
* Snicker.
** Kinda. Engineers like to say "it depends" in response to questions. Heat treaters say it as a matter of course.
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I like to make my own flap horns , so that I can get the correct geometry. Where can I get a small supply of tweakable 3/32" and 1/8" wire? Music wire just doesn"t do the job.
Keith Varley
McMaster Carr
use the A2 tool steel (drill rod)
available in 3 or 6 foot lengths
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McMaster Carr
use the A2 tool steel (drill rod)
available in 3 or 6 foot lengths
Isn't that kind of overkill? Plain old stainless rod is probably way cheaper.
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I like to make my own flap horns , so that I can get the correct geometry. Where can I get a small supply of tweakable 3/32" and 1/8" wire? Music wire just doesn"t do the job.
Keith Varley
If you are silver brazing the horn to the music wire joiner you already have a tweakable horn. The temperature needed for this will certainly take the hardness out of the wire either side of the horn.
HH
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Isn't that kind of overkill? Plain old stainless rod is probably way cheaper.
1/8" 8888K181 $ 3.14 per 3 foot length
3/32" 8888K211 $ 2.86 "
You call that overkill ?
::)
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Isn't that kind of overkill? Plain old stainless rod is probably way cheaper.
I doubt it, but both are essentially free compared to everything else. And you have to weld or braze it, and the drill rod eliminates the need to re-temper the wire.
Brett
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Thanks !!
I am now awaiting my first ever order from MC Master Carr. They sure do have a wonderful selection of stuff. Keith
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Keith
When I read this first time thought you were making the actual control horn from wire.
Some of the locals and I made wire horns for combat for the tiny bit of weight saved in the polar moment part of things. Was not really worth it in my opinion but they looked fancy and cool. this did allow the loads to be spread out more so that was a plus.
Now after rereading looks like you mean the joiner piece for the surface 1/2s with a horn welded or soldered on.
About 25 years ago I started using welding rod on R/C scale and pattern airplanes so that tweaking was easier and did not damage the elevator or flap/aileron structure.
3/16 TIG rod is good for the big stuff and 1/8 TIG for small airplanes.
Some will say you need the stiffness of spring steel or other. This has proven untrue even when loads are put into say the left surface and then feed through the 'U' to the other surface on 12+lb R/C airplanes.
David
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I got some if the A2 tool steel drill rod fro MC Master Carr, and it appears to be excellent and just what I had hoped for.Good service and reasonable. Keith
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Keith, I have used that same wire from McMaster Carr since 1970 with no bad results and it is wonderfully tweakable but bomb-proof. I think you'll learn to love it. I use very high temp silver solder. No, not the 2% silver stuff, what I get from McMaster Carr is 45% silver, cad free by Harris Co. You need to get the special flux for it which is lacking a label on my jar, I've had it for years!!! The beauty of this flux is that the silver solder flows ONLY where the flux cleans, allowing you to control both strength and weight of the joint. It solders quite nicely with a propane torch.
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The ultimate reference for making horns.
http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=331672&mesg_id=331672&listing_type=search