Got the Aileron Pushrods welded!

smittysrv · Post by **smittysrv** » Sat Jan 12, 2008 12:38 pm

I forgot to mention that the guy at the Chopper shopped told me before I left to not file anything down. Otherwise I would compromise the structural integrity of the weld.

captain_john · Post by **captain_john** » Sat Jan 12, 2008 1:20 pm

Hmmmm, that is an interesting passage from the "bible". I ran it past a friend of mine who is probably one of the most highly qualified and certified welding inspector/guru around.

He and I both agree that the reason they guard against the practice of filing or otherwise removing material from the weld after it has been made is because without good initial penetration (difficult to prove in the field without destructive testing) the strength could be affected.

Good penetration begins with good prep. That means beveling the faces of the substrate materials and then penetrating additionally with the heat applied with the filler material.

In our estimation, the Feds would rather have you leave the additional material in place because they are assuming the worst case scenario happened in the field prior to welding... no beveled surfaces and possible poor penetration.

If we were assured of proper technique, this additional material could certainly be removed.

Will, Don't think that my feathers are ruffled, as I am sure yours aren't either. We are just dwelling in the minutia of aircraft building and that is what makes our planes better than spam cans!

I thought you were doing high voltage wiring! If you were, we could drink the cold ones WHILE we worked!

...and Smitty, maybe he had poor penetration and knows it?

I just like using that word, PENETRATION!

...and make sure you LUBE the end!

CJ

weezbad · Post by **weezbad** » Sat Jan 12, 2008 2:02 pm

captain_john wrote:He and I both agree that the reason they guard against the practice of filing or otherwise removing material from the weld after it has been made is because without good initial penetration (difficult to prove in the field without destructive testing) the strength could be affected.

most likely true

captain_john wrote: Good penetration begins with good prep. That means beveling the faces of the substrate materials and then penetrating additionally with the heat applied with the filler material.

well material this thin doesnt require beveling

captain_john wrote:
In our estimation, the Feds would rather have you leave the additional material in place because they are assuming the worst case scenario happened in the field prior to welding... no beveled surfaces and possible poor penetration.

again probly true but im certain they have doen extensive testin to come to this reasoning...i mean even at the ESAB cutting/welding center here at the college do all kind of x-ray tesing and destructive testing. come to think of it, if a students project cant be bent 180 deg after grinding off the weld as mentioned they fail the practical. and get to start over...you and i know its all about PENETRATION.

and thorough fusion of course

captain_john wrote: If we were assured of proper technique, this additional material could certainly be removed..

true true

captain_john wrote: Will, Don't think that my feathers are ruffled, as I am sure yours aren't either. We are just dwelling in the minutia of aircraft building and that is what makes our planes better than spam cans!

no doubt my friend

captain_john wrote: I thought you were doing high voltage wiring! If you were, we could drink the cold ones WHILE we worked!

i leave that stuff to my friend, 220 is as high as i go. something about the black wire being hot is stupid

smithhb · Post by **smithhb** » Sat Jan 12, 2008 4:49 pm

William,

Thank you for finding the reference...I knew it was in there but could not put my finger on it. Clearly, this applies to any load bearing steel structure which is designed to carry critical loads...like the aileron pushrods...

I will be inspecting my pushrod welds on a regular basis!

captain_john · Post by **captain_john** » Sat Jan 12, 2008 5:29 pm

220, 211... whatever it takes!

CJ

jim_geo · Post by **jim_geo** » Sat Jan 12, 2008 8:46 pm

Hmm, Capt'n Johns' a movie buff.

weezbad · Post by **weezbad** » Sat Jan 12, 2008 10:26 pm

maybe he is mister mom...i use that line till this day except i go wth 220 221 whatever it takes....gotta love it...

i tried out for the job but my wife said no

captain_john · Post by **captain_john** » Sun Jan 13, 2008 9:57 am

No, not really a movie buff. I just have heard them all being in the trade.

Back in the day when I pulled out my right angle drill, everyone would ask me if I had seen the movie Body Double. To this day I haven't but I hear it has a a murderer who uses an electrician's drill to kill people.

Dunno... Never saw it.

CJ

tmbg · Post by **tmbg** » Sun Jan 13, 2008 11:13 pm

I went and made my pushrods.

Here's what aviation welds look like

smittysrv · Post by **smittysrv** » Mon Jan 14, 2008 6:06 am

THAT is nice!

Good job!

captain_john · Post by **captain_john** » Mon Jan 14, 2008 6:13 am

Everybody's doin it!

Looks great, Ian!

CJ

tmbg · Post by **tmbg** » Mon Jan 14, 2008 10:45 am

thanks

I drilled a 3/32" hole in the pushrod near one end before welding the end... it really is pretty necessary, otherwise the heat makes the air inside the tube expand, and it pops little holes in the weld pool. I'm going to pour linseed oil in the holes and then weld up the hole. After that, I'll mask off the threads and prime and paint the pushrods.

I also put my aileron bellcrank together for the left wing.

weezbad · Post by **weezbad** » Mon Jan 14, 2008 4:27 pm

i hate to keep on being the "doubting thomas/ nervous nellie" but dont you think the heat treat on the threaded portion is rendered useless with the welding process? doesnt this need to be reheat treated? that is what i was taught in school.

captain_john · Post by **captain_john** » Mon Jan 14, 2008 5:22 pm

Well Will, from what I have learned, the weld usually fails in the HAA (Heat Affected Area). This is rarely the weld itself, but the surrounding material, like you said.

When you temper a metal, you bring it all up to temperature and cool it all together. Soooo, ya. We are on the same page.

The question is, need these be tempered?

I dunno?

CJ

Dan A · Post by **Dan A** » Mon Jan 14, 2008 7:07 pm

I just drilled the holes and rivited the ends into the tubes. No worrys about tempering or cracked welds! They work fine!

Dan

cjensen · Post by **cjensen** » Mon Jan 14, 2008 7:26 pm

Hehe! Me too Dan...

Not sure what the deal is with the pic not showing up...

Oh, I get it, the picture location has an eight in parenthesis in it...is there a fix for that Spike?

Post by **Spike** » Tue Jan 15, 2008 10:56 am

Yeah, it appears that the parens are screwing up the parser. Typical escape sequences dont seem to help. Ill have to look at the code itself to see if there is a way around it.

Spike

smittysrv · Post by **smittysrv** » Tue Jan 15, 2008 8:59 pm

OK, one more question about the rod end bearings. It seems a little weird to me that the "jam" nuts are all alone in holding the rod end bearings in place. Just about everything on my Cessna is either a lock nut or a nut that is wired down. What's the story here?

weezbad · Post by **weezbad** » Tue Jan 15, 2008 9:29 pm

the rod ends are over half the way screwed in so this means if one came loose it couldnt unthread it self... it would bottom in the other end bearing first... i still would love to have them saftied somehow..

cjensen · Post by **cjensen** » Tue Jan 15, 2008 11:06 pm

Here's how I saftied my elevator push tube (the little one, same as the aileron push tube)...

The instructions say that if the threads can't be engaged half way or more, that some means of safetying them is needed.

This will work even if you have more than half engaged, and want peace of mind. I did this because I had less than half the threads engaged on either end.

I took some quarter inch ID AL tubing, cut it in half, and then cut each half to the length I needed. The half AL tube simply rests on top of the threads, then I zip tied them to the threads. I also torque sealed the nut for easy inspection. The nuts can't move unless both zip ties fail, and the torque seal lets go...

RivetBangers.com

Got the Aileron Pushrods welded!

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man

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