"Alyson" wrote in message
...
On Sep 17, 10:03 am, Kristian Ukkonen wrote:
On 9/17/2011 19:49, Alyson wrote:

What type of metal rod/strip could I insert in a pad that could then
be molded to fit a knee without breaking when bent and unbent
repeatedly?

Just design it so that stress stays elastic..
After that take cyclic fatigue into consideraton..

Some spring steel flat might be a good start..

Thanks...
Would spring steel hold its shape in order to hold the pad on my knee
until I wanted to unbend it to take it off?

You've asked a simple question that may have a surprisingly complex answer.
What Kristian is talking about is metal that can be given a shape and then
can bend within its spring limits. Like any spring, after you bend it, it
snaps back to its original shape. You need metalworking equipment to get the
initial shape to fit around your knee. I don't think that's what you want.

It sounds like you want something that you can bend to shape, probably by
hand, and then un-bend to take it off. That sounds like the bendable metal
splints that the military uses for temporarily splinting bone breaks,etc.
They're available on the consumer market. Just Google "bendable metal
splint," probably without the quote marks.

Underlying your question is what kind of metal can stand being bent back and
forth, holding its shape after each bend, but which will allow you to shape
it as you need to around your knee. Unless you're into the engineering of
things, buying a bendable metal splint probably is the best place for you to
start.

Metals break after repeated bending into new shapes, unless they're springs
and they don't get bent into a new "set" shape. But you probably want a new
"set" shape each time you put it on or take it off. Finding the right metal,
of the right stiffness, strength, and re-bend-ability (not really a word
g) is problematic. But with the bendable splints, the makers have worked
out all of those issues for you.

They may not be the right stiffness. I have no idea. And even they will have
a limited number of times you can bend and re-bend them. They may be very
capable of handling the re-bending, but they aren't meant to be re-used
multiple times. Still, they may have the best properties you'll find for
what you want.

Good luck.

--
Ed Huntress