With an EDM you would mold the face of the electrode as a mirror image of
the finished part. EDMers have tricks they use to accomplish this. It could
be something like copper plating an existing chip and using that as the
electrode, or using a chip to form an investment cast mold, and then cast
the electrode. They also use an abrading method, where a part is charged
with grit, a special tool applies an orbiting motion and it crush forms the
graphite electrode, there is also ultrasonic machining with an abrasive
slurry that produces good detail.

I once mounted a old copper penny as a cheap test electrode and sank it into
a block of aluminum, didn't get great results because the copper eroded too
quickly, but then again i'm a noob EDMer.

Tony

"Bob Engelhardt" wrote in message
...
Karl Vorwerk wrote:

... counterfeiting slot tokens with and EDM ...

I thought it was interesting that they showed him cutting the dies with
the EDM, but didn't say anything about he drove the EDM. I.e., how he
measured/scanned the "real" token to get the digital representation.
Maybe the EDM has a built-in scanner, for copying parts. Anybody know?

Bob