On Thu, 24 May 2012 19:39:52 -0500, Karl Townsend
wrote:

On Thu, 24 May 2012 16:37:37 -0700 (PDT), MrFightGuy
wrote:

On May 24, 5:45*pm, "Jim Wilkins" wrote:
"MrFightGuy" wrote in message

...

Hey all:

I'm wondering what it will take to put a 2-3 inch curve in a 21 to
24-
inch wide sheet if 1/8 inch thick 7075-T6 aluminum....

Nathan

Saw off a narrow strip and experiment.

Isn't 6061 good enough?

jsw

Nope. I've made swords out of 6061, and my 7075 swords pulverize them
with little effort. It's gotta be 7075 so that the shields can stand
up to the beating that my swords dish out. And no, I can't start
making swords out of 6061. It just doesn't have the tensile strength
(and therefore the durability) I want in my products.

I see nobody with great knowledge answering your query. I'm not an
expert but 20 tons has to be a great plenty to press AL to the curve
you desire.

SWAG: I'd think aluminum has a higher strength than that.

pi x r x r = 3.14 x 12 x 12 = 452.16 sq. in. /88.46426 psi.
I'd tend to disagree that the 20T press would work, but how much of
the bending -would- it do, I wonder?


Of course if you have the dies, getting press work would be trivial
and inexpensive. My query would be how to make dies without the huge
expense of machining from billet.

Home casting, I'd wager. My buddy cast some nice little sprockets
after machining one from plate. He likes piston aluminum for most
things he cast. My CNC router holder is one of his castings that we
machined. Maybe Nathan has beaucoup 7075 scraps and shavings, so he
could cast from them. It beats a $2/lb return from the scrappers.

--
When a quiet man is moved to passion, it seems the very earth will shake.
-- Stephanie Barron
(Something for the Powers That Be to remember, eh?)