I have an application where I need to make some small stainless steel core
pins for a mold. I have some .090 spring wire that would probably work
fairly well after I straighten it. Straightness does not have to be
perfect, so I'll probably just do that part by hand. Then I run into my
issue. I need to taper it from .090" down to about .070" over a reach of
about 1.25 inches.

The only thing I could think of is to to a shallow v block and clamp that it
the tool holder on the mini lathe. Then lay a file against one end of the V
block and slowly bring it back until its just scuffing the wire at the 1.25
inch mark. The grove is to hold the wire from bending against the cutting
force of the file. My concern is if I will be able to continue to cut the
wire with the file as it work hardens from the action of the file. My other
concerns are that I have my hands so close to the spinning lathe, and that
this seems to be a very hand skilled approach to the problem.

No the pre tapered pins for sale from McMaster absolutely WILL NOT work for
this application. Besides. I already have several hundred feet of .090"
316 spring wire left over from a past project.

I guess its time to go play with a file and see....

Bob La Londe wrote:
I have an application where I need to make some small stainless steel
core
pins for a mold. I have some .090 spring wire that would probably work
fairly well after I straighten it. Straightness does not have to be
perfect, so I'll probably just do that part by hand. Then I run into my
issue. I need to taper it from .090" down to about .070" over a reach of
about 1.25 inches.

The only thing I could think of is to to a shallow v block and clamp
that it
the tool holder on the mini lathe. Then lay a file against one end of
the V
block and slowly bring it back until its just scuffing the wire at the
1.25
inch mark. The grove is to hold the wire from bending against the
cutting
force of the file. My concern is if I will be able to continue to cut
the
wire with the file as it work hardens from the action of the file. My
other
concerns are that I have my hands so close to the spinning lathe, and
that
this seems to be a very hand skilled approach to the problem.

No the pre tapered pins for sale from McMaster absolutely WILL NOT
work for
this application. Besides. I already have several hundred feet of .090"
316 spring wire left over from a past project.

I guess its time to go play with a file and see....





Sounds a bit like some items I made a few years ago but the taper was
shallower and longer but the idea may apply. Details from the dropbox

http://www.mwdropbox.com/dropbox/longtaper.txt
http://www.mwdropbox.com/dropbox/longtaperfront.jpg
http://www.mwdropbox.com/dropbox/longtapertop.jpg

"Bob La Londe" wrote in message
...
I have an application where I need to make some small stainless steel
core
pins for a mold. I have some .090 spring wire that would probably
work
fairly well after I straighten it. Straightness does not have to be
perfect, so I'll probably just do that part by hand. Then I run
into my
issue. I need to taper it from .090" down to about .070" over a
reach of
about 1.25 inches....

I very reluctantly designed #0-80 fillister head screws 1.25" long
into a set of narrow, tightly packed optical assemblies and had to
make the first batch myself. They weren't as difficult as I had
expected to turn and thread from stainless TIG rod, either 1/8" or
5/32", I don't remember and still have some of both. I reduced the rod
from full to final size about 0.2" at a time, supported closely in a
collet. I think I found that I could cut full depth in one pass.

Perhaps you could turn a series of 20 evenly spaced steps of 0.001"
each and then file it with a fine single-cut "pillar" or "hand" file
until the steps disappear. You could smooth them further with fine
sandpaper backed by the file.
jsw

If the 0.070" is at the end of the wire set up for electropolishing and
repeatedly dip the wire into the solution and remove it. I've made needle
points 1/8 to 3/8" long that way, you should be able to do 1.25" of taper.
I was never successful just slowly removing the piece from the solution
once, it was too irregular. Repeated dipping averages all of that out.
With the tiny surface area you won't need much of a power supply, maybe 5-10
V and 1 amp.

-----
Regards,
Carl Ijames
"Bob La Londe" wrote in message ...

I have an application where I need to make some small stainless steel core
pins for a mold. I have some .090 spring wire that would probably work
fairly well after I straighten it. Straightness does not have to be
perfect, so I'll probably just do that part by hand. Then I run into my
issue. I need to taper it from .090" down to about .070" over a reach of
about 1.25 inches.

The only thing I could think of is to to a shallow v block and clamp that it
the tool holder on the mini lathe. Then lay a file against one end of the V
block and slowly bring it back until its just scuffing the wire at the 1.25
inch mark. The grove is to hold the wire from bending against the cutting
force of the file. My concern is if I will be able to continue to cut the
wire with the file as it work hardens from the action of the file. My other
concerns are that I have my hands so close to the spinning lathe, and that
this seems to be a very hand skilled approach to the problem.

No the pre tapered pins for sale from McMaster absolutely WILL NOT work for
this application. Besides. I already have several hundred feet of .090"
316 spring wire left over from a past project.

I guess its time to go play with a file and see....

"David Billington" wrote in message
...
Bob La Londe wrote:
I have an application where I need to make some small stainless steel
core
pins for a mold. I have some .090 spring wire that would probably work
fairly well after I straighten it. Straightness does not have to be
perfect, so I'll probably just do that part by hand. Then I run into my
issue. I need to taper it from .090" down to about .070" over a reach of
about 1.25 inches.

The only thing I could think of is to to a shallow v block and clamp that
it
the tool holder on the mini lathe. Then lay a file against one end of
the V
block and slowly bring it back until its just scuffing the wire at the
1.25
inch mark. The grove is to hold the wire from bending against the
cutting
force of the file. My concern is if I will be able to continue to cut
the
wire with the file as it work hardens from the action of the file. My
other
concerns are that I have my hands so close to the spinning lathe, and
that
this seems to be a very hand skilled approach to the problem.

No the pre tapered pins for sale from McMaster absolutely WILL NOT work
for
this application. Besides. I already have several hundred feet of .090"
316 spring wire left over from a past project.

I guess its time to go play with a file and see....





Sounds a bit like some items I made a few years ago but the taper was
shallower and longer but the idea may apply. Details from the dropbox

http://www.mwdropbox.com/dropbox/longtaper.txt
http://www.mwdropbox.com/dropbox/longtaperfront.jpg
http://www.mwdropbox.com/dropbox/longtapertop.jpg

That's a way to do it. I had not really though of clamping a guide to the
ways like that, but I think it might work if I can get a good cut on the
wire.

"Carl Ijames" wrote in message
...
If the 0.070" is at the end of the wire set up for electropolishing and
repeatedly dip the wire into the solution and remove it. I've made needle
points 1/8 to 3/8" long that way, you should be able to do 1.25" of taper.
I was never successful just slowly removing the piece from the solution
once, it was too irregular. Repeated dipping averages all of that out.
With the tiny surface area you won't need much of a power supply, maybe
5-10 V and 1 amp.


I did consider some form of solvent forming, but I may need to make a bunch
of these. Seems like it would be a little slower than I might like.



-----
Regards,
Carl Ijames
"Bob La Londe" wrote in message ...

I have an application where I need to make some small stainless steel core
pins for a mold. I have some .090 spring wire that would probably work
fairly well after I straighten it. Straightness does not have to be
perfect, so I'll probably just do that part by hand. Then I run into my
issue. I need to taper it from .090" down to about .070" over a reach of
about 1.25 inches.

The only thing I could think of is to to a shallow v block and clamp that
it
the tool holder on the mini lathe. Then lay a file against one end of the
V
block and slowly bring it back until its just scuffing the wire at the
1.25
inch mark. The grove is to hold the wire from bending against the cutting
force of the file. My concern is if I will be able to continue to cut the
wire with the file as it work hardens from the action of the file. My
other
concerns are that I have my hands so close to the spinning lathe, and that
this seems to be a very hand skilled approach to the problem.

No the pre tapered pins for sale from McMaster absolutely WILL NOT work
for
this application. Besides. I already have several hundred feet of .090"
316 spring wire left over from a past project.

I guess its time to go play with a file and see....

Oops. So much for the no political content warning. Good thing I'm not
target shooting today. I'ld totally miss the target and break the support
wire.

In article ,
"Rita - Guns Suck - ************" wrote:

"Carl Ijames" wrote in message
...
If the 0.070" is at the end of the wire set up for electropolishing and
repeatedly dip the wire into the solution and remove it. I've made needle
points 1/8 to 3/8" long that way, you should be able to do 1.25" of taper.
I was never successful just slowly removing the piece from the solution
once, it was too irregular. Repeated dipping averages all of that out.
With the tiny surface area you won't need much of a power supply, maybe
5-10 V and 1 amp.


I did consider some form of solvent forming, but I may need to make a bunch
of these. Seems like it would be a little slower than I might like.

Do them in parallel, each with its own current-limiting resistor, to
ensure that the current spreads evenly.

Joe Gwinn

Bob La Londe wrote:
I have an application where I need to make some small stainless steel core
pins for a mold. I have some .090 spring wire that would probably work
fairly well after I straighten it. Straightness does not have to be
perfect, so I'll probably just do that part by hand. Then I run into my
issue. I need to taper it from .090" down to about .070" over a reach of
about 1.25 inches.

The only thing I could think of is to to a shallow v block and clamp that it
the tool holder on the mini lathe. Then lay a file against one end of the V
block and slowly bring it back until its just scuffing the wire at the 1.25
inch mark. The grove is to hold the wire from bending against the cutting
force of the file. My concern is if I will be able to continue to cut the
wire with the file as it work hardens from the action of the file. My other
concerns are that I have my hands so close to the spinning lathe, and that
this seems to be a very hand skilled approach to the problem.

No the pre tapered pins for sale from McMaster absolutely WILL NOT work for
this application. Besides. I already have several hundred feet of .090"
316 spring wire left over from a past project.

I guess its time to go play with a file and see....

A wet grinding wheel would work for this too. You can just hold stuff
against those with your hands.

stuff like small shafts can be allowed to just spin on their own. Want a
taper- press harder on one side.

"Bob La Londe" wrote in message
...
I have an application where I need to make some small stainless steel core
pins for a mold. I have some .090 spring wire that would probably work
fairly well after I straighten it. Straightness does not have to be
perfect, so I'll probably just do that part by hand. Then I run into my
issue. I need to taper it from .090" down to about .070" over a reach of
about 1.25 inches.

The only thing I could think of is to to a shallow v block and clamp that
it
the tool holder on the mini lathe. Then lay a file against one end of the
V
block and slowly bring it back until its just scuffing the wire at the
1.25
inch mark. The grove is to hold the wire from bending against the cutting
force of the file. My concern is if I will be able to continue to cut the
wire with the file as it work hardens from the action of the file. My
other
concerns are that I have my hands so close to the spinning lathe, and that
this seems to be a very hand skilled approach to the problem.

No the pre tapered pins for sale from McMaster absolutely WILL NOT work
for
this application. Besides. I already have several hundred feet of .090"
316 spring wire left over from a past project.

I guess its time to go play with a file and see....


I balled parked it. I found a piece of pre-straightened .094 and cut it
into suitable lengths. Then I just chucked a piece up in the cordless drill
and free handed them against sanding disc on the side of my benchtop sander.
They went way faster than anything else I might have done. Amazingly when I
checked it with a caliper it wasn't perfectly linear, but it was pretty darn
close. I just spun the drill the opposite direction of the disc and it
tapered very quickly and it was very easy to control.