Thorp Air Command - T18.net

I couldnt get the (6061-T4) flap rib to bend smoothly like it shows in the plans. I shrunk/stretched, bent and cussed all to avail. I ended up putting in relief notches. I dont see why thats not ok. Any reason why not?

Have you tried to anneal it? Take a Vis a Vis pen and mark it up. Then take a torch and heat evenly until the ink is burned off. Let air cool. Then it will be pliable again.
If you can’t get it to lay down, use a lead slap. To make one, make a tray 1” by 1’ by about 1/4” deep. Melt lead into it. Once cool, use it to slap the flange down. The idea is to hit the whole flange at once. It will actually shrink the metal.
Cubes

I didn't try annealing...annealing was next on my list when I decided to put in the relief notches. I will make another rib and try the annealing route. One question about annealing 6061 T4...do I need to quench 6061 T4 after heating or just let it cool down by itself?

Air cool. Work it as soon it's cool as it will begin to harden within a half hour.

_________________
Bob Highley
N711SH
SN 835
KLAL

Perfect, thank you!