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Aileron bellcrank rivets

Mark Jackson

Active Member
Patron
I fabricated the aileron bellcranks today. After prepping everything, inserted the AN470D4-12 rivets called for in the plans. The looked way too long but I double and triple checked. Tried to squeeze the first one and it started to fold over. The second was a little bent but acceptable. The third one squeezed straight but then it sort of popped. It appears to me that the shop head cracked and slipped over. Happened on 5 of 8. Going to toss these and build new ones.

Has anyone else experienced this? Am I doing something wrong squeezing? Using a regular cup and die which works fine on shorter rivets.

Don't want the same to happen next time.

IMG_2193_1.jpg


IMG_2192_1.jpg
 
I had the same problem. Clamp them in a vice and use a rivet gun. You will get much better results than the squeezer. Squeezers never work well on long rivets in my experience.
 
It also helps to grind the rivets down to 11.5 length. Drill a #30 hole in a piece of 1/8" thick angle and use it to hold the rivet square against your disc grinder, pushing on the factory head of the rivet until you achieve the desired length. You are correct that the -12 length is too long for this application. There are previous posts available on this issue. Some choose to weld, but you can quite successfully do this with rivets. Good luck.
Tom.

http://www.vansairforce.com/community/showthread.php?t=143791
 
I remember this, way back in 2000. Good grief, you'd think Vans would have corrected this by now. I really think it's part of the scheme to make sure you spend a lot of time on stupid things like this. Why not spec a rivet at the right size? I can hear them telling the FAA that by the time the builder gets done fixing these things, they'll have way more than 51% invested in this kit.:eek:
 
Rivet gun

Yep. For some reason they clinch with the squeezed. It's do able if you squeeze super slow so the work harden a little inside the tube. Gun works better.
 
Doh, I searched the RV-8 forum instead of the general forum. Thx for the pointer.

It also helps to grind the rivets down to 11.5 length. Drill a #30 hole in a piece of 1/8" thick angle and use it to hold the rivet square against your disc grinder, pushing on the factory head of the rivet until you achieve the desired length. You are correct that the -12 length is too long for this application. There are previous posts available on this issue. Some choose to weld, but you can quite successfully do this with rivets. Good luck.
Tom.

http://www.vansairforce.com/community/showthread.php?t=143791
 
Push rods

Not to be too picky, but those are pushrods, not bell cranks. The bell crank is a weldment, and I was curious to see what rivets you were talking about, since I didn't recall any rivets in the aileron bell cranks.
 
C-frame dimpler

Holding the pushrod straight and using the C-frame dimpler as a riveter got the job done with a few hammer blows.

Cup set in the bottom and a flat set in the moving shaft. If it's all square when you hit the first time it then folding over doesn't seem to occur.
 
Gage.

We found that if you use your 1.5 rivet gage and don't set it at the top of the curve but at the bottom on the tubing the rivet would be the length you want. Then just make sure the rivet is dead center on the set and go slow and straight. If you put the squeeze "C" jaw in a vice and holt the rod on a box out from the vice on the bench, we hand no problems with this assembly. Just what we did, hope it helps. Yours R.E.A. III #80888
 
Well, the bellcranks are scrap now. This is a picture of one of the rivets that "popped". One whack with a punch and it snapped leaving the jagged edge below.

I tried a couple -11 rivets. They don't produce a large enough shop head. So I took the last couple -12 rivets, cut about 1/16th off with a dremel, scotch-brited them smooth, then squeezed and got okay results.

Popped:
IMG_2197.jpg


Sheared:
IMG_2199.jpg


Good:
IMG_2196.jpg
 
Wow... surprised at your result. I just squeezed mine the other day and it worked out really well. I use the Cleaveland Tool Main Squeeze, which has better leverage than most hand squeezers. I've botched a few in the past... but my pushrod rivets turned out fine.
(I know... I'm no help at all)
 
Got the new parts today including a bunch of -12 rivets to practice with.

Cut/drilled the tubes, inserted the rivets, cut about 1/16 off with a dremel tool, then polished them and squeezed. They weren't perfect but were acceptable.

Cutting the rivet

IMG_2234.jpg


squeezed

IMG_2236.jpg
 
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