Today hasn't been good. I've ruined several parts blanks without forming a successful part. Can't get the metal to form around the nose of the form blocks (flaperon ribs, slat ribs, elevator ribs) without kinking the metal. my measurements are all good, my parts blanks are all good, but the aluminum just wants to kink and crack, and won't work it's way around the radius. Any suggestions anyone? Part of the problem seems to be the soft plywood forming blocks, but I've literally just ruined 8-10 ribs on 3 different sets of blocks.

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Comment by Timothy Aanerud on November 2, 2015 at 10:17pm

Greg, I have some solid round metal cylinders that have a 1/8" radius on the edges.  I use them to pound out any bottle cap effect.  

Comment by Greg Harris on October 26, 2015 at 8:40am

I got the noses to form well, finally. Just took a bit of adjusting the dimensions on by blanks correctly. But now I'm in business. Flaperon nose ribs are all done. Elevator nose ribs are done. Just have the slat ribs and wing nose ribs to do now, and a couple of the full ribs that correspond to the nose ribs I've already done.

Comment by Brian Fitzpatrick on October 23, 2015 at 6:01pm


My two cents.  I made one form block of 5051 x 1/4" and the other half of MDF.

Heat with propane torch: not sizzling but too hot to handle. If you get my drift.

Keep the radius narrow.  About 1/8" or tight 3/8".  Good luck.

Comment by Russell Johnson on September 24, 2015 at 9:57am

Try annealing the front part of the rib. With an acetylene torch set so it produces black soot, coat one side of the nose of the rib, using a neutral flame heat the opposite side until the soot just disappears, do not overheat The aluminum should now be dead soft, making it a lot easier to form. 

Comment by Greg Harris on September 23, 2015 at 5:58pm
Pat, I had the same problem with MDF. The wood just flexes and deformed too much when I hammer away. I think I'm hitting too hard, when many, softer hits would produce better results.
Comment by Spencer Rice on September 23, 2015 at 5:52pm
Mine did the same thing. I had to trim them back and use a smaller mallet.
Comment by Greg Harris on September 23, 2015 at 5:50pm
Yeah, I can take a picture. There is definitely too much mat'l on the nose...I think I figured out why. They are all cracking and kinking around the nose radius because there's no place for the material to go. I used a flexible straight-edge when putting in the taper for the flange material, instead of drawing a straight line tangent to the nose radius at the 3mm. Working on it now.
Comment by Spencer Rice on September 23, 2015 at 5:37pm

Can you take a picture of one of your ribs that cracked? Probably just have to much material on the nose.

Comment by Pat Kelly on September 23, 2015 at 5:30pm

Have you tried to made your forms out of mdf? 

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