Aileron pushrods

[bestbearhawk1231]

Hello,
Are the nuts welded onto the ends of the aileron pushrods standard 1/4-28 nuts or are they heavy nuts like the flap pushrods? Will a standard nut be strong enough after the temper is messed with from the welding heat and is there enough thread engagement or would I be better off welding 2 nuts together then welding them to the pushrod?

[X'N]

This place seems to have a good selection of threaded inserts. Not sure if they have the size you need. http://store.metzperformance.com/hom...ction=0&page=1

[alaskabearhawk]

You need a heavy nut. Threaded rod ends need at least 5 threads of engagement. Those 4130 threaded inserts look very cool. I wish I would have known about these last month when I posted about the trim arm. It would have saved me a lot of time on the lathe!

[Enewton57]

I was just having a conversation with Bob about this very subject. Bob prefers the heavy nut. He said his general rule of thum is that you should have at least as much threadengagement as the diameter of the Rod End shank. So a Rod End with a 1/4" shank should have 1/4" thread engagement.

[bestbearhawk1231]

Thanks for the help guys. My local Fastenal dealer has been having trouble getting 1/4-28 heavy nuts...for about 8 months now. It seems that the Fastenal dealers who have them do not want to give them up. I have not tried their online store yet. I have been hesitant to go online since I only need a small handful and the shipping would cost me more than the nuts would. That is why I was asking about welding 2 nuts back to back then welding the nut assembly on the push rod tube. I wasn't trying to be cheap, just have a bunch of standard 1/4-28 nuts laying around. Also, if I have to make an order, how much #25 chain do I need and what tooth # gear do I need for the trim wheel? Thanks again for the help.

[alaskabearhawk]

I wouldn't use anything from Fastenal for an aircraft. This explains it best as to the differences in quality of aircraft hardware vs. "normal" hardware. Read the second paragraph::

www.sportair.com/articles/Aircraft Hardware - What You Need To Know.html

Aurora Bearings has a different take on the rod thread engagement:

Q - What is the minimum thread engagement required to support the advertised load ratings in the Aurora Bearing Company catalog?

A -The minimum thread engagement is 1.5 times the major thread diameter unless otherwise stated.

http://www.aurorabearing.com/technical-faqs.html

[bestbearhawk1231]

Thanks Paul for your help. What is the AN, MS, or NAS part # for a 1/4-28 heavy nut? I haven't been able to find one which is why I was at fastenal and other online places trying to get heavy fine thread nuts. Around a year ago on the old forum I had asked a question regarding what the plans meant when they referred to a "heavy nut" so I could understand what was meant by the description. I don't see any difference between buying a structural heavy nut and welding on it vs someone who chucks a piece of steel into a lathe and makes a threaded insert to weld on such as metz performance link. At least the structural heavy nut is guaranteed to meet ASTM A194 specs before the welding heat is put to it. I understand the difference between hardware store hardware and aviation grade hardware, I worked on corporate jets for 5 years and would never cheap out on my plane by running down to home depot for a bag of bolts. I had gone to Fastenal looking for the structural heavy nuts since in the part of the country I live in, they are the "premier" hardware supplier. In my original post I had asked about welding 2 standard nuts together to get the required thread engagement since I would not get the required engagement with one nut. What I meant by a "standard nut" was AN315-4, which I have a hundred or so of. I apologize for not making myself more clear in the original posting. Keep the help coming, it really is appreciated.

[alaskabearhawk]

Gotcha...that makes sense now. That is a good question and one I have wondered about. I don't find any AN "heavy" nut at all. Possibly an AN310 because it's taller. I like the Metz stuff. I just made some threaded ends for my trim drive arms and I suppose you could do the same with a threaded insert and some rosette welds to hold them in.

http://www.mykitlog.com/users/display_log.php?user=yeeeha&project=527&category=7248&log=180384&row=2

http://www.mykitlog.com/users/display_log.php?user=yeeeha&project=527&category=7248&log=180443&row=1

[bestbearhawk1231]

I may have come off a bit harsh regarding making your own rod ends and the Metz ends and I apologize for that. Those Metz ends are definitely nice, although they didn't have the proper size for the tubing. You definitely do beautiful work and I hope my parts turn out half as nice as yours. Unfortunately, I don't have convenient access to a lathe yet so my options are limited at this point. I am hoping to find one at an auction or to find a used 3 in 1 machine like a Smithy for a decent price. In the past when one has come up for sale I didn't have the funds available. At this point, my options are to drive 4 hours to the aviation college and use theirs, hire out the work, or buy completed assemblies. I will have to go around and get quotes for the work I need done and use the quote to see if I can justify buying a machine. I have talked to several machine shops around and they all charge around 100 bucks to turn the machine on and a per hour charge after that. Seems like I could come close to paying off a lower end smithy with the project. I have been leaning towards a mill/lathe combo machine since I the mill would be nice to have and I don't have room for 2 big machines, most of the parts I would be making would be relatively small anyway. I enjoy spending the time building parts so I would rather not buy completed assemblies since I am in it for the knowledge and have more time than cash.

[alaskabearhawk]

Holy crap! I didn't take it at all like that...no offense taken...really.

The Metz 1/2 .058 1/4x28 rod end would work in the 7/16ths .049 aileron rod with a little modification. The inner diameter of the 1/2 .058 tube is .384. The inner diameter of the 7/16ths .049 is .340. Take the Metz end and put it on a 1/4x28 bolt and chuck that in a drill or drill press. Using a file slowly work the end down to fit the 7/16ths tube. The ridge on the end would only stick out 1/32nds of an inch and will be obliterated when it's welded.

[Enewton57]

Thanks for the help guys. My local Fastenal dealer has been having trouble getting 1/4-28 heavy nuts...for about 8 months now. It seems that the Fastenal dealers who have them do not want to give them up. I have not tried their online store yet. I have been hesitant to go online since I only need a small handful and the shipping would cost me more than the nuts would. That is why I was asking about welding 2 nuts back to back then welding the nut assembly on the push rod tube. I wasn't trying to be cheap, just have a bunch of standard 1/4-28 nuts laying around. Also, if I have to make an order, how much #25 chain do I need and what tooth # gear do I need for the trim wheel? Thanks again for the help.

Yes I would think two regular 1/4" nuts welded together would be just fine.

[alaskabearhawk]

When in doubt, answer the question I guess!

A foot of chain should be plenty as the trim doesn't move much. The trim wheel that Bearhawk Aircraft sells comes with a 9 tooth sprocket.

[Mark Goldberg]

We give 14" of chain when someone buys the chain along with the trim wheel. Mark

[bestbearhawk1231]

Thanks for all your help guys, I still can't figure out how people built planes back in the 50s without all of the forms and reference materiel we have these days!