On 2013-04-22, Karl Townsend wrote:
I'm on a snipe hunt for a special compression spring. it needs to be
conical with the large end OD around 0.390" or a bit smaller (like
3/8) and a small end OD of 1/4" or a bit smaller. When the spring is
compressed to 0.225" high it needs to push 8 - 10 lbs. force. Similar
straight compression springs have 6 coils of 0.028" music wire and
constant of 25 lb./in.

I've been trying on line catalogs with no joy, so far. Anybody suggest
a good source to try?

It sounds like a custom spring. How many do you need? If
enough (thousands at a guess), contact a maker of springs and ask them
for a quote.

If on the order of 20 to 100, set up to turn them on your lathe.

Here is an excellent resource on how to make springs. I don't
remember anything in it about conical springs, but I would turn up a
tapered mandrel and wind the springs on that. Perhaps a tapered thread
on the mandrel to guide the spacing of the wire.

Is the taper in this to allow the spring to compress to a flat
spiral at maximum compression?

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---