On Fri, 08 Oct 2010 11:14:21 -0700, Tim Wescott
wrote:

On 10/08/2010 10:47 AM, Karl Townsend wrote:
On Fri, 08 Oct 2010 09:47:17 -0700, Tim
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?

Can't help you with I.D.s but "the Kid" raced super modified for a
couple years. The skin he used was AL, easy enough to bend on our hand
brake, cut on our foot stomp shear and it had to be hardened. I could
ask him the grade if this is what you're after.

Where I'm coming from is more this:

I've brushed up against the need -- mine, or acquaintances -- to bend up
aluminum landing gear for model airplanes. If you use the usual 3003
"nice and soft" aluminum for this it bends each and every time you land,
if it doesn't do so the first time you set the plane on it.

But you can buy nice aluminum landing gear, some of which is advertised
as being heat treated to T6 condition. It's nice stuff -- you really
have to thump it to make it bend, and it's at least ductile enough that
you can generally bend it back and go flying again after a hard landing.

So I'm wondering -- before I go pay money for something wrong -- if this
is something that I can just get and use, or if I'd have to mess around
with hardening.

To date I've always been able to make up my LG from wire -- but there
are times when a nice sheet aluminum gear would work out better.
Get 6061t6 or 6061t650 and cold bend it - minimum bending radius is
3X the thickness? Something like that. Actually I looked it up - 2X
thickness is minimum radius 3x preferred.
Or you can anneal it, bend it, and let it sit for about 6 months and
it will be age-hardened back to something like a T3.