On Wed, 20 Dec 2017 13:23:34 -0700, Bob La Londe
wrote:

On 12/20/2017 1:07 PM, rangerssuck wrote:
On Wednesday, December 20, 2017 at 2:54:13 PM UTC-5, Bob La Londe wrote:
I'm not sure how this will work out, but I am going to try it. This is
strictly a fun personal project to find out.

The goal is a two sided embossing die for paper. One is a positive and
the other is a negative. I know I could just have one made cheap by the
guys who make notary stamps, but this one will have a 3D image of my mom
from a painting my grandmother did when she was dating my dad. I want
to make it myself.

I had to reread that twice to figure out what you meant, and to
realize that "my grandmother wasn't dating my dad." That's a really
cool, deeply sentimental project, BTW.


Here is the process I am going to try.

1. Machine pocket with all the features raised at the bottom of the
pocket. 2hrs apx

2. Spray it with UMR.

3. Make a backing plate the size of the pocket with some screws set in
it for anchoring.

4. Fill the pocket with casting resin, and place the backing plate into
the resin.

5. Pull resin plug at listed demold time and set aside. 10-15 minutes.

6. Machine away side walls of aluminum positive plate leaving just some
holding tabs.

7. Remove positive from bar stock and clean up on bench sander.

8. Wait 24 plus hrs for full cure of resin.

9. Mate the two halves and mount them for pressure turning on the
lathe. Turn the resin plug down to match the aluminum plug.

What is "pressure turning on the lathe"?


10. With halves mated mount on spring plates.

Do you think there might be a problem with the positive and negative being the same size without clearance for the paper? I can imagine that you could end up with more of a punch than an embosser. Of course, I'm as likely to be wrong about this as not, and it won't cost much to give it a try.

Yes, interference fits do give one trouble, unless you're aiming for a
few tenths press-fit.


Interesting project.

Yes!


I am concerned about that possibility, but I have a couple commercial
embossing dies I bought to study, and they seem to cut as much as
emboss. You can hear the paper tearing when you emboss the paper.

Are they paper- or metal-embossing dies? Metal stretches better than
paper.


Ideally I'd need atleast .003" difference, but title and information
pages of books vary in thickness. I'd have to find a happy medium. It
might be ok since I did design everything with about 5 degrees of draft
angle to make it easier to pull the resin plug.

What kind of depth are you aiming for in the emboss? Anything deep
and you'd have to use a thick, wetted paper, wouldn't you? Or put
paper-making soup in the mould and heat?

Have you tried wetting the paper and heating the dies just prior to
pressing?


I'm generating code right now.

Is there a set algorithm for mould relief between parts? That might
be very handy to know. Does it take an AI?

--
A sound mind in a sound body is a short but full
description of a happy state in this world.
--John Locke