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Custom made AN hardware?

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Will Aldridge

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hey guys, I've designed a completely new flaperon mixer system for my plane and need a custom bolt. Basically threaded on each end with a right hand thread on one end and a left hand thread on the other, like this:20200921_205248.jpg

It will be the same application, a female rod end bearing on each end. 3/16" diameter roughly 3.5-3.75" long. Just in case you're wondering that's just a little longer than the hardware pictured so I can't just use one of those.
Anyone know who can make one? Or maybe just maybe does it already exist somewhere that it can be bought?
 

akwrencher

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If you can't find one, you could probably have a couple made at your local machine shop. Buy some extra long AN bolts, cut off head, have the left hand threads cut. Or maybe find a tool supplier for left hand dies. Just some ideas.
 

fly2kads

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Does it have to be a bolt, or could you use a double-ended threaded stud? It may be easier to make, if you can't find one off the shelf.
 

Will Aldridge

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Does it have to be a bolt, or could you use a double-ended threaded stud? It may be easier to make, if you can't find one off the shelf.
Theoretically I could use a piece of all thread, but if it fatigues and snaps, the left flaperon will flutter in the breeze and potentially ruin my day if not my life, so I'm looking for rolled threads.

How difficult is it to machine rolled threads? Is it in the capability of most machine shops?
 

rv7charlie

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AL tube/riveted threaded inserts, or 4130 tube/welded threaded inserts. Any length you want. Might be simpler with male rod ends.
 

Dana

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You can buy RH/LH studs, but why? Unless you really need to adjust it in place, under tension, use RH threads on both ends.
 

wsimpso1

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hey guys, I've designed a completely new flaperon mixer system for my plane and need a custom bolt. Basically threaded on each end with a right hand thread on one end and a left hand thread on the other, like this:View attachment 102022

It will be the same application, a female rod end bearing on each end. 3/16" diameter roughly 3.5-3.75" long. Just in case you're wondering that's just a little longer than the hardware pictured so I can't just use one of those.
Anyone know who can make one? Or maybe just maybe does it already exist somewhere that it can be bought?
If you can tolerate one-half turn adjustments, just do it all in right hand hardware. You can buy Grade 8 dichromate treated threaded rod. On the other hand, if you must finer adjustments or be able to tension the system with opposite handed threads, do like BoKu said - make a short push/pull rod with appropriate female threads and male thread rod end bearings. Left hand taps in UNF sizes are available.

Those long slender threaded rods give me the willies. Loaded in compression, the buckling load for them can be quite low. I have visions of one buckling and you having a highly asymmetric flap situation - might be both unrecoverable and even undiagnosed after the accident that results. I prefer more stout push rods between rod ends unless the whole rod is too short to fit one.

Billski
 
Last edited:

wktaylor

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NAS363-thru-369 Control Rod and Tube Assembly~1/4-28UNF-3A Thread Illustrates similar rod-designs that were 'codified' decades ago...

In the for-what-it's-worth category, the attached TRISTAR Illustrated Fastener catalog has cool/useful illustrations... with Spec Numbers... for older generation common 'parts'. When I get stuck for parts [spec numbers] I try this as last resort.

IF You can down load the specs... the Part definitions are pretty straight forward to interpret.

NOTE.
BAC* PNs are Boeing Aircraft Company PNs.
Other PNS [NOT... AN*, NAS*, MS*, BAC*, etc] are TRISTAR PNs.

CAUTION: the company TRISTAR NO LONGER EXISTS
 

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Will Aldridge

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Repurpose a turnbuckle barrel and put rod ends in each end? Drill for safety wire?
Think you might have found the easiest solution. There are some 4" long barrels with 1/4 28 threads on aircraft spruce. I'm not at my computer so I don't know for sure but they might be too long. Here's hoping it works.
 

Jay Kempf

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It would allow adjusting without disassembly and a little more redundancy. It's still a single point to fail item with consequences but lots of examples of that, elevator pushrods, etc....
 

Will Aldridge

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Well the 4" barrel is most definitely too long. The 2 1/4" barrel would only have about .33" of each rod end threaded into it. Don't think that would be adequate.
 

Geraldc

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1600818516858.png
Not sure if these are the size you need but easy to make as others have suggested.
 

wktaylor

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Concur... never use a wire-rope turnbuckle for 'push' [compression loads... 'pull', only..

The NAS363-thru-369 Assys I cited were designed for high strength push-pull [static or dynamic] operation.... and relatively fine adjustment.

CAUTION: full threaded rods are not intended for anything other-than very short lengths and light push-pull. Buckling/bending/cracking is the killer.

Use solid rods with short threaded ends for substantial compression... short lengths Only.

ALSO the rod-ends [clevis or bearing, etc...] MUST be locked into position after adjustment … by mechanical positive locking devices... jam-nut, cotter-pin, locking-tab washers, etc. Photo of DGI parts show adjustable shank and rod-ends with jam-nuts. AND always using marking compound across these joints to ensure instant visual inspection if they 'slip' [come-loose].
 
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