"Maxwell" wrote in message
...

"J.Kahn" wrote in message
.. .
I need to make bends of about 30 degrees in a 3/4 x .049 longeron tube,
with a tight bend radius, no more than 3 inches. Can I do the bend hot
without wrinkling the tube by free bending or do I need a supporting die
of some kind? Anybody have any specific techniques?

John

I think I would try slipping a tension spring inside the tube if you can
find one the right size. A 5/8" o.d. might be close enough, it would
leave about .025" depending on how close the tube and the spring are to
actual size.

Also, I think a 3/4" electrical conduit bender will give you about a 4"
radius, depending on brand. If that doesn't work, you might try making a
square shouldered bending shoe out of 3/4" plywood for a tube that thin.
Don't know for sure, just a wag. Thirty degrees isn't very far.

Max

Come to think of it, you might be able to wrap another spring around the
outside, and go 30 degrees without a benging shoe. But obviously I'm still
guessing.

*Nothing is too difficult for the man that doesn't have to actually do it.*