Tim Wescott wrote:
Yes, there's a lot of different alloys that can be tempered to T6 --
so feel free to educate me.

Is it at all a sensible thing to think that I could get some 40 - 60
mil aluminum sheet that's already tempered to somewhere between T3 and
T6 (harder is better), and be able to put 45 degree bends in it? 60
degree? 90? Bend radius? Is this something that could be done on a
normal brake? Clearly springback would be an issue, but is it just a
pain, or a real @#$% pain?

Or did I accidentally smoke something this morning, and do I just have
to get some decent alloy in an annealed condition, bend it up, and
figure out how to bake it?

I don't know what the minimum recommended bend radius is with that
material so would go with what Clare has mentioned in another post. My
experience is with 2" wide by 3/8" thick 6082 (IIRC) T6 and I was
bending it 90 degrees at about a 5" radius former to end up with a 6"
radius. I had to bend it to about 120 - 130 degrees to end up with a 90
degree bend due to the spring back. I had a section of 2" x 2" x 16swg
steel box section about 5' long clamped to it for mechanical advantage.
I would say your landing gear shouldn't be a problem to bend in T6
providing you use a sensible radius for the bends.