I need to make a cutting die with the following dimensions:
Length at least 6"
Width of 1" +-0.005"
I will be cutting 120 mil plastics.
I planned on taking a piece of surface ground square stock larger than
1" square and drill a 1/4" hole in each corner to give me a 1/8"
radius. Then mill out the center of the stock to get my 1" inside
dimension.

My question is are most dies sharpened on the outside using a special
grinding wheel setup?
Or can I pivot my Bridgeport head to mill at an angle and thus
producing my cutting edge bevel on the outside?

Thanks
Steve

"gtslabs" wrote in message
oups.com...
I need to make a cutting die with the following dimensions:
Length at least 6"
Width of 1" +-0.005"
I will be cutting 120 mil plastics.
I planned on taking a piece of surface ground square stock larger than
1" square and drill a 1/4" hole in each corner to give me a 1/8"
radius. Then mill out the center of the stock to get my 1" inside
dimension.

My question is are most dies sharpened on the outside using a special
grinding wheel setup?
Or can I pivot my Bridgeport head to mill at an angle and thus
producing my cutting edge bevel on the outside?

Thanks
Steve


1. You'll want a 22.5 degree on the inside of the "box". If you try to put
the bevel on the outside,your cut will be both undersized and, itself,
beveled.

2. For your best [aka cleanest] cut, hone the beveled side with a diamond
hone.

3. You'll get better results rounding the corners before milling out the
center. It's not hard to do with a belt sander or a bench grinder since
you're only knocking off the sharp edge slightly.

4. Use the mill vertically to remove the center stock and then (and only
then) bevel the outer walls.

You are doing this the hard way. For this kind of application you don't
need to muck with a surface grinder and hardening steel. A steel rule die
is what they use to cut gaskets and you can get them cheap. These you don't
even sharpen, you just remove the dull steel and replace it.

Google steel rule die or go to your local cardboard box company and ask them
where they get their dies from.


--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.
"gtslabs" wrote in message
oups.com...
I need to make a cutting die with the following dimensions:
Length at least 6"
Width of 1" +-0.005"
I will be cutting 120 mil plastics.
I planned on taking a piece of surface ground square stock larger than
1" square and drill a 1/4" hole in each corner to give me a 1/8"
radius. Then mill out the center of the stock to get my 1" inside
dimension.

My question is are most dies sharpened on the outside using a special
grinding wheel setup?
Or can I pivot my Bridgeport head to mill at an angle and thus
producing my cutting edge bevel on the outside?

Thanks
Steve

FWIW, I was just quoted $105 to have a small steel rule die made. The part
it will make is essentially a 2"x4" rectangle with a rectangular hole in the
center, (2) 3/16" at opposing corners and (2) 3/16" slots at the opposite
corners. Larger and more complex dies have run us $250 to $500.

Seems pretty cheap to me.

"Roger Shoaf" wrote in message
...
You are doing this the hard way. For this kind of application you don't
need to muck with a surface grinder and hardening steel. A steel rule die
is what they use to cut gaskets and you can get them cheap. These you
don't
even sharpen, you just remove the dull steel and replace it.

Google steel rule die or go to your local cardboard box company and ask
them
where they get their dies from.


--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube,
then
they come up with this striped stuff.
"gtslabs" wrote in message
oups.com...
I need to make a cutting die with the following dimensions:
Length at least 6"
Width of 1" +-0.005"
I will be cutting 120 mil plastics.
I planned on taking a piece of surface ground square stock larger than
1" square and drill a 1/4" hole in each corner to give me a 1/8"
radius. Then mill out the center of the stock to get my 1" inside
dimension.

My question is are most dies sharpened on the outside using a special
grinding wheel setup?
Or can I pivot my Bridgeport head to mill at an angle and thus
producing my cutting edge bevel on the outside?

Thanks
Steve

gtslabs wrote:

I need to make a cutting die with the following dimensions:
Length at least 6"
Width of 1" +-0.005"
I will be cutting 120 mil plastics.
I planned on taking a piece of surface ground square stock larger than
1" square and drill a 1/4" hole in each corner to give me a 1/8"
radius. Then mill out the center of the stock to get my 1" inside
dimension.

My question is are most dies sharpened on the outside using a special
grinding wheel setup?
Or can I pivot my Bridgeport head to mill at an angle and thus
producing my cutting edge bevel on the outside?

Thanks
Steve


Steve... Talk to Tom at Southwest Die in Phx.Az. (602-484-0474) You can
fax him with a full size plan and he can take it from there.
I've been using him for years ~ the dies are clean, spot on, and very
fairly priced. Maybe a 2, 3, or 4-p die might work well for you... ask
for pricing... Shipping will prolly be negligible.

(I'm not tied in with SW Die... just a very happy customer)

Bill