On 07/26/2010 02:01 PM, Ed Huntress wrote:
"Pete wrote in message
ster.com...

Tim Wescott wrote:

Argh. Just bent up a landing gear for a model plane. 1/8" "Music wire"
from K&S. Nominally the same thing, except one was the tail-end of an
older piece, and one was brand spanking new.

The new piece is _soft_ -- more welding rod that nice hard music wire.
I had noticed this before with some 1/16" stock, but it didn't penetrate
my poor thick skull. K&S is obviously going down the "consumers are
stupid" route.

Any ideas on where I might best get good old fashioned three-foot
straight pieces of music wire? I see that McMaster has it -- in one
foot lengths, and Small Parts has it -- mostly in six foot lengths. I
can deal with the odd length issue, but I'd sure like to order with
confidence that I'm getting something decent, not just the same metallic
noodles that I can get from the local hobby shop.

McMaster typically specifies the exact characteristics, metal alloy,
etc. for it's items. Suggest giving them a call to see if they can
supply it in 3' or 6' lengths.

I assume that Tim has a good feel for what's "hard" in 1/8" music wire.
That's the largest legitimate diameter of real music wire, and it's the
softest. Still, it's not soft. I think the ultimate tensile is around
110,000 psi or something like that; the Rc hardness would still be pretty
good, compared to any ordinary plain-carbon steel.

I have a good _feel_ for it, but not a feel that's calibrated in
numbers, unfortunately.

I'll have to see what I can get from McMasters, I guess. They have a 3'
assortment that sure lights up the 'candy shop' part of my brain, but
there's the expense...

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html