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?

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..

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?

Use a beanbag, can fill it with metal shot if you like (but
popcorn works just as well).

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?

Are you looking for support or protection?

Metals thick enough to provide support won't be flexible enough to do this.

Now if you're looking for protection then I would go with something like
fine ring chain mail. Or woven metal fabric.

--
Steve W.

"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

In article
,
Alyson wrote:

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?

There is no metal that will do this forever. But soft aluminum wire is
pretty good, and cheap. Art stores sell such wire for use as armatures
in plaster sculpture.

Black or galvanized iron wire is also pretty good, in the thicker
grades. McMaster-Carr is a good source.

You will also need wirecutting pliers and a file (to smooth the cut ends
of the wire).

Joe Gwinn

On Sep 17, 11:16*am, Joseph Gwinn wrote:
In article
,





*Alyson wrote:
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?

There is no metal that will do this forever. *But soft aluminum wire is
pretty good, and cheap. *Art stores sell such wire for use as armatures
in plaster sculpture.

Black or galvanized iron wire is also pretty good, in the thicker
grades. *McMaster-Carr is a good source.

You will also need wirecutting pliers and a file (to smooth the cut ends
of the wire).

Joe Gwinn- Hide quoted text -

- Show quoted text -

Thanks so much to all of you for the ideas...

On Sat, 17 Sep 2011 14:16:05 -0400, Joseph Gwinn
wrote:

In article
,
Alyson wrote:


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?

There is no metal that will do this forever. But soft aluminum wire is
pretty good, and cheap. Art stores sell such wire for use as armatures
in plaster sculpture.


And used much like the OP's application in the toobers in the toy
"Toobers & Zots."

http://en.wikipedia.org/wiki/Toobers_%26_Zots

--
Ned Simmons

On Sat, 17 Sep 2011 09:49:01 -0700 (PDT), 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?

A hinged type.

Nexxxxxxxxxt!

--
Shake off all the fears of servile prejudices, under which weak minds
are servilely crouched. Fix reason firmly in her seat, and call on her
tribunal for every fact, every opinion. Question with boldness even the
existence of a God; because, if there be one, he must more approve of
the homage of reason than that of blindfolded fear.
-- Thomas Jefferson

On 17/09/2011 19:16, Joseph Gwinn wrote:
In article
,
wrote:

On Sep 17, 10:03 am, Kristian 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?

There is no metal that will do this forever. But soft aluminum wire is
pretty good, and cheap. Art stores sell such wire for use as armatures
in plaster sculpture.

Black or galvanized iron wire is also pretty good, in the thicker
grades. McMaster-Carr is a good source.

You will also need wirecutting pliers and a file (to smooth the cut ends
of the wire).

Joe Gwinn

Excellent advice. Pure lead is pretty good too. If you are old enough to
remember the flexi-curve rulers used by draughtsmen, these had two thin
strips of spring steel, one each side of a square lead core (the whole
lot encased in PVC). The sheet lead used for roof "flashing" is pretty
ductile.

On Saturday, September 17, 2011 11:16:05 AM UTC-7, Joseph Gwinn wrote:
In article
,
Alyson wrote:

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?

There is no metal that will do this forever. But soft aluminum wire is
pretty good, and cheap.

Well, there aren't any other wiseasses around today, so I better mention:

Ga (Gallium metal)

Gallium will deform indefinitely, because (in contact with a knee) body heat
will melt it.

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?

What's wrong with plain ol' ordinary off-the-shelf knee pads?

Thanks,
Rich

On Sat, 17 Sep 2011 15:42:08 -0700, whit3rd wrote:
On Saturday, September 17, 2011 11:16:05 AM UTC-7, Joseph Gwinn wrote:
On 9/17/2011 19:49, Alyson acoo... wrote:
On Sep 17, 10:03, 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?

There is no metal that will do this forever. But soft aluminum wire is
pretty good, and cheap.

Well, there aren't any other wiseasses around today, so I better
mention:

Ga (Gallium metal)

Gallium will deform indefinitely, because (in contact with a knee) body
heat will melt it.

In that case, why not just go with mercury, already melted. You
ought to be more sensible about these things! Obviously, strips of
gold, the most malleable metal, would be the best thing to use. I
think a cross-section of about 1/8" x 1/2" would be good, because
that's about the size used for aluminum strips in temporary casts
or braces for wrists, elbows, etc., and gold, silver, and aluminum
all have about the same Young's modulus.

--
jiw

On Sat, 17 Sep 2011 20:03:54 +0300, 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..

A human leg type knee? Most braces use opposed bearing "hinges".

Google Townsend Design for a company that makes them locally.

Very! light weight and everyone Ive talked to that uses them, loves them
as opposed to every competitors models

Gunner

"In the history of mankind, there have always been men and women who's goal
in life is to take down nations. We have just elected such a man to run our
country." - David Lloyyd (2008)

On Sat, 17 Sep 2011 11:22:07 -0700 (PDT), Alyson
wrote:

On Sep 17, 11:16*am, Joseph Gwinn wrote:
In article
,





*Alyson wrote:
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?

There is no metal that will do this forever. *But soft aluminum wire is
pretty good, and cheap. *Art stores sell such wire for use as armatures
in plaster sculpture.

Black or galvanized iron wire is also pretty good, in the thicker
grades. *McMaster-Carr is a good source.

You will also need wirecutting pliers and a file (to smooth the cut ends
of the wire).

Joe Gwinn- Hide quoted text -

- Show quoted text -

Thanks so much to all of you for the ideas...


http://www.townsenddesign.com/Townse.../Products.html

They are located in Bakersfield, California and Ive done some work for
them in the past.

Good stuff!

Gunner

"In the history of mankind, there have always been men and women who's goal
in life is to take down nations. We have just elected such a man to run our
country." - David Lloyyd (2008)

On Sep 17, 12:00*pm, Newshound wrote:
On 17/09/2011 19:16, Joseph Gwinn wrote:









In article
,
* *wrote:

On Sep 17, 10:03 am, Kristian *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?

There is no metal that will do this forever. *But soft aluminum wire is
pretty good, and cheap. *Art stores sell such wire for use as armatures
in plaster sculpture.

Black or galvanized iron wire is also pretty good, in the thicker
grades. *McMaster-Carr is a good source.

You will also need wirecutting pliers and a file (to smooth the cut ends
of the wire).

Joe Gwinn

Excellent advice. Pure lead is pretty good too. If you are old enough to
remember the flexi-curve rulers used by draughtsmen, these had two thin
strips of spring steel, one each side of a square lead core (the whole
lot encased in PVC). The sheet lead used for roof "flashing" is pretty
ductile.

Ours just had a spring holding the lead and the metal strips.

On Sep 17, 4:43*pm, James Waldby wrote:
On Sat, 17 Sep 2011 15:42:08 -0700, whit3rd wrote:
On Saturday, September 17, 2011 11:16:05 AM UTC-7, Joseph Gwinn wrote:
On 9/17/2011 19:49, *Alyson acoo... wrote:
On Sep 17, 10:03, 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?

There is no metal that will do this forever. *But soft aluminum wire is
pretty good, and cheap.

Well, there aren't any other wiseasses around today, so I better
mention:

Ga *(Gallium metal)

Gallium will deform indefinitely, because (in contact with a knee) body
heat will melt it.

In that case, why not just go with mercury, already melted. *You
ought to be more sensible about these things! *Obviously, strips of
gold, the most malleable metal, would be the best thing to use. *I
think a cross-section of about 1/8" x 1/2" would be good, because
that's about the size used for aluminum strips in temporary casts
or braces for wrists, elbows, etc., and gold, silver, and aluminum
all have about the same Young's modulus.

--
jiw

Pure gold shouldn't work harden.
Karl

If you're looking to bend the metal to fit a knee then straighten it then bend it again, it depends on how sharp the bend is and how many cycles you need. A wire coat hanger will if the bend is not sharp go through a surprising number of cycles before it fails, but eventually it will.

You might want to consider a friction-based approach. Google "joby gorillapod" for one example.

If you're willing to go with a process and not a product, get some 10-gage or 12-gage copper electrical wire from Home Depot or wherever and anneal it after every use--you can anneal it with a burner on a gas stove--just get it red hot and throw it in a bucket of water. Cut a bunch of extras and do a week's worth at a time.

If you want to get fancy there might be a way to do what you want to with nitinol.

On Sep 18, 6:56*am, wrote:
If you're looking to bend the metal to fit a knee then straighten it then bend it again, it depends on how sharp the bend is and how many cycles you need. *A wire coat hanger will if the bend is not sharp go through a surprising number of cycles before it fails, but eventually it will.

You might want to consider a friction-based approach. *Google "joby gorillapod" for one example.

If you're willing to go with a process and not a product, get some 10-gage or 12-gage copper electrical wire from Home Depot or wherever and anneal it after every use--you can anneal it with a burner on a gas stove--just get it red hot and throw it in a bucket of water. *Cut a bunch of extras and do a week's worth at a time.

If you want to get fancy there might be a way to do what you want to with nitinol.

Segmented may be the way, ala gorillapod. I've got a indicator stand
that uses about the same approach using spheres and socketed
cylinders, all with a hole in the center. A tensioned cable through
the center holds it all together, in whatever configuration it happens
to have. May not do the support thing(wasn't quantified) but should
wrap and unwrap indefinitely.

Stan

Alyson wrote:
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?

Ah, that's much clearer ... we were thinking that you wanted this to
bend as your knee bent. To use it to hold you knee pads on, you would
want spring steel in the "holding" shape. Then it would _flex_ enough
to remove it, without needing to bend it to a different shape.

As a wild-ass guess, I would say the piece should be about 3/4 to 1"
wide & maybe .030 thick. That would give a pretty strong hold & you
need that.

Bob

on 19/09/2011, Bob Engelhardt supposed :
Alyson wrote:
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?

Ah, that's much clearer ... we were thinking that you wanted this to bend as
your knee bent. To use it to hold you knee pads on, you would want spring
steel in the "holding" shape. Then it would _flex_ enough to remove it,
without needing to bend it to a different shape.

As a wild-ass guess, I would say the piece should be about 3/4 to 1" wide &
maybe .030 thick. That would give a pretty strong hold & you need that.

Bob

Wouldn't Velcro be better.I recently made some foam rubber pads, that
we christened "Shoes for Knees" for a child who cannot walk but crawls
around.
Reports from the mother say they work well.
The rubber was a ompact foam which I was able to mold to a knee shape
by warming it to about 200degrees F.
I could get a better definition of the rubber if anyone is interested.

--
John G.