Wing Skin Stiffeners behind flap

[Chewie]

Does anyone have a technique for bending these on a leaf brake? The zig-zag character of these stiffeners is stumping me. I have access to a 10 ft. leaf brake, but the bending leaf is too wide for a downward facing bend to hang over so it can lay flat. There is no clearance under the foot either... it would pancake it. Do I need to add a long spacer somewhere, or is this just the wrong tool for the job?

image.png image.png

Thanks!

[arborite]

That’s a challenge on that brake. There’s a youtuber building a bearhawk that had a clever idea using an aluminum extension ladder as a break. he inserted the metal between the two ladder halves and clamped them together to grab the workpiece. then hand formed the bend. not sure that’s precise enough for your piece but it might be worth looking at.

[sjt]

This is what I did




stiff.jpg


stiffener2.jpg

[sjt]

the trailing edge was done much like Bob recommends but I also used a 3/32 drill rod to make sure nothing went wrong
trail.jpg

[sjt]

http://bearhawksafety.com/Patrol/patrolengineer.html

If you so get access to a 10 foot brake you might want to bend up these stiffeners. This was a change from a few years ago. Not a safety change.

I once heard that there were stiffeners also added aft of the main spar on Mark's airplanes. If someone knows whether that is so can you point out how far aft of the spar.

s.jpg I do not know about all of the versions but this was done on the PATROL.

[Chewie]

Thanks all. I came across another 10' brake with a much narrower (1/2") bending leaf, which will allow bends spaced as little as 1/2" apart in either direction.