Seeking Aileron Pulley Bracket Advice

[r1200gsDave]

I am working on the aileron pulley bracket this weekend for my Pietenpol. I am seeking any advice you might have.

[taildrags]

r1200GSDave-

I have never built this bracket myself, so there isn't much that I can offer. However, seeing that the plans call for brazing the inner brackets to the main "U" pulley holder bracket, I have read about problems with brazing 4130 steel and cracks developing. If you are making your parts out of 4130 and you can weld this rather than brazing it, that would be better but if not and since this is not primary structure, it probably doesn't make any difference.

[B Wilson]

Don't mean to hijack your thread, but I am also building these and I have a question. I am using 4130 and plan to gas weld them, but it looks like you need to put the attachment bolts through the bracket before you weld them up. Any thoughts from anybody?
Thanks,
Brent

[B Wilson]

Don't mean to hijack your thread, but I am also building these and I have a question. I am using 4130 and plan to gas weld them, but it looks like you need to put the attachment bolts through the bracket before you weld them up. Any thoughts from anybody?
Thanks,
Brent

[taildrags]

Brent; if the part is held up to the wood, you're right... it will not be possible to insert the bolts with the part assembled. However, if the bolts are inserted into the holes in the metal and they're not a tight fit, the part could then be moved into position and the bolts pushed through the holes in the wood. Good luck getting a socket or wrench on the bolt heads though. the only way to hold the bolts from turning will be to jam a screwdriver or chisel in there and then tighten the nut.

This is one of those parts that you might think about welding the bolts into the U-bracket before welding on the inner pulley brackets and then it's all good.

[B Wilson]

Thanks Oscar
I think inserting them and welding them to the u bracket is a good idea.
Keep up the good work. I really appreciate your commitment to replying to everybody's questions. It keeps things interesting on our site.
BW

[r1200gsDave]

This is one of those deceivingly "simple" parts that take an enormous amount of time. I have a pretty good prototype and 5 scrap parts.....

Welding the thin 4130 is above my skill. But I have found a workable design that I can make.

The bolt does not need to welded in place. You will have to temporarily bend the inner tab in to fit a nut driver on it.

[r1200gsDave]

This is a horrible mess.... none of these are airplane parts. Just me trying to figure out how to make the part and work on my welding skills....

The best I got to is a backwards L that I flat weld in place.

[r1200gsDave]

I have two winners! the "L" version worked well and I am ready to powder coat the parts tomorrow.

[r1200gsDave]

Here are some more photographs of how I make the bracket.

As usual It took me a days to figure out how I would finally make the part. now that i have made it I can make it in about 30 minutes.
However I still cannot make two identical parts. They are really similar, but hand made parts still have slight variances.

Peace

[at7000ft]

See post below.

[Lownslow]

Thats what I did too.

[at7000ft]

Made the two bends in the outer strap (verifying equal angles with an angle gauge), then drilled the 3/16" holes for the AN3 bolts, these holes were angled and reamed slightly to allow the bolts to be inserted at a slight angle from perpendicular (and then rotated to perpendicular for mounting to the spar). The two hoIes for the pulley bolt were then drilled at each end based on the pulley radius (measured with the AN3 bolt inserted, you don't want the edge of the pulley dragging on the bolt head after all this work). Cut a small piece of wood to be clamped between the outer strap and the inner strap to be welded, welded with a tig welder. Then match drilled the hole for the pulley bolt into the end of the inner strap perpendicular to the outer strap on a drill press.

Rick H

[at7000ft]

Don't mean to hijack your thread, but I am also building these and I have a question. I am using 4130 and plan to gas weld them, but it looks like you need to put the attachment bolts through the bracket before you weld them up. Any thoughts from anybody?
Thanks,
Brent

Not necessary if the holes reamed slightly to allow the bolts to be inserted at an angle an them moved to perpendicular.

rh