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?

Karl

On Apr 22, 7:50*pm, 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?

Karl

I made a compression spring at the beginning of the month. In fact I
made several before I got it right. There are some good web sites
with information. So if you can't find one already made, you can make
one yourself.

I used the lathe, but turned the spindle by hand as my lathe will
only go down to 4 threads per inch and I needed about 2 turns per
inch. So turned the spindle a half turn and then moved the carriage a
quarter inch and repeat. It came out surprisingly well. The reason I
had to make several was to get the mandrel the right size so the
finished spring was the necessary diameter. i ended up making the
mandrel out of oak from a pallet . .750 was too big and .625 vas too
small so the metal rods i had on hand would not work.


Dan

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
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--- Black Holes are where God is dividing by zero ---

"Karl Townsend" wrote in message
...
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.



The usual use for a conical spring is because they can be compressed down to
a much shorter height ( IE one that's made .028 wire can be compressed to a
height of appx .028)

In contrast, a straight compression spring made with the same diameter wire
will take up .028 on each end amd another .028 for each turn.

All of which makes me wonder why you are wanting a conical spring if you are
only compressing it to .225 height

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


I go through about 500 springs per month, ordering from "custom spring
products" in Hillsboro, Oregon.

Suggest call-they might have something in stock....

http://www.custom-spring.com/

wrote in message
...
-I made a compression spring at the beginning of the month. In fact I
-made several before I got it right. There are some good web sites
-with information. So if you can't find one already made, you can
make
-one yourself...
-Dan

My 10" South Bend has enough back-gear torque to wind 1/8" SS TIG rod
into conical spiral wood stove handles, on a steel mandrel threaded 4
TPI with a half-round bit.

There is a traditional clock part called a "fusee" which is similar to
the mandrel for winding a conical spring:
http://upload.wikimedia.org/wikipedi..._With_Cord.png
jsw

On Apr 23, 9:18*am, "Jim Wilkins" wrote:


My 10" South Bend has enough back-gear torque to wind 1/8" SS TIG rod
into conical spiral wood stove handles, on a steel mandrel threaded 4
TPI with a half-round bit.


My lathe has enough torque in back gear and with the VFD it can be
very slow. But no easy way to get 2 tpi.

Many years ago a friend and I made springs out of quartz. It takes a
little experimentation . We used a quartz mandrel about 12 mm in
diameter. The quartz being wound was about 0.5 mm in diameter. You
have to heat the quartz being would with a oxy- acet. torch enough to
soften it , but not so much that it sticks to the mandrel. We used
power feed on a little Craftsman 6 inch lathe and about 8 tpi .

Dan

On 23/04/13 14:18, Jim Wilkins wrote:
wrote in message
...
-I made a compression spring at the beginning of the month. In fact I
-made several before I got it right. There are some good web sites
-with information. So if you can't find one already made, you can
make
-one yourself...
-Dan

My 10" South Bend has enough back-gear torque to wind 1/8" SS TIG rod
into conical spiral wood stove handles, on a steel mandrel threaded 4
TPI with a half-round bit.
I was wondering about doing that recently for a similar application but
when I looked my local farm supply had chipping hammers with coil spring
handles for £1.70 UKP (about $2.60) so just bought one and cut the head
off and welded it where required.

There is a traditional clock part called a "fusee" which is similar to
the mandrel for winding a conical spring:
http://upload.wikimedia.org/wikipedi..._With_Cord.png
jsw

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?

Karl

Contact spring from a flashlight battery clip maybe?

http://www.reidsupply.com/products/t...ssion-springs/

http://home.earthlink.net/~bazillion/types.html


--
Steve W.

"David Billington" wrote in message
...
On 23/04/13 14:18, Jim Wilkins wrote:

My 10" South Bend has enough back-gear torque to wind 1/8" SS TIG
rod
into conical spiral wood stove handles, on a steel mandrel threaded
4
TPI with a half-round bit.
I was wondering about doing that recently for a similar application
but when I looked my local farm supply had chipping hammers with
coil spring handles for £1.70 UKP (about $2.60) so just bought one
and cut the head off and welded it where required.

The stainless wire door handle doesn't feel hot in a location where
previous wood handles slowly carbonized. jsw

On Monday, April 22, 2013 4:50:37 PM UTC-7, 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.

Well, the stainless springs in Delta faucet seal kits are about that size.
They're a bit light on the force side, though.

You can often stack Belleville washers (adding them in parallel for
higher force, or in series for lower) to get a
target stiffness. They're conical, but not as extreme as your
description (nearly flat disks).
Four McMaster-Carr 9712K58 in series would be about right.

On Apr 22, 5:50*pm, 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?

Karl

Some single-control faucets used such springs, replaced valve spindles
with them a whole bunch of times at the parents' place.

Stan

On Mon, 22 Apr 2013 18:50:37 -0500, 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?

Karl

Thanks everybody for all the tips. I had posted this request on
several sites. Turns out another guy needed the EXACT same spring and
had it custom made. he's GIVING me a couple.

Karl

On Tuesday, April 23, 2013 9:18:18 AM UTC-4, Jim Wilkins wrote:


There is a traditional clock part called a "fusee" which is similar to

the mandrel for winding a conical spring:

http://upload.wikimedia.org/wikipedi..._With_Cord.png

jsw

Hi,

Interestingly, a Fusee is a "thread" following a hyperbola, not just a tapered thread.
They are a bit more difficult to make.

I have written a program to CNC a Fusee on a lathe.
Quite surprised myself with that one.

--

PaulS