Cutting copper?

As a retired master mechanic, I still work on vehicles. It’s like the Mafia, you can’t get out, you know too much. Anywho, I’m messing around with a little project vehicle of mine called a Daihatsu Rocky.
Long story short I want to cut a copperhead gasket for it. I have hammer soft pure copper sheet of the appropriate thickness. I’m still designing the head gasket and have a 2.2kw water cooled spindle and vfd on the way Just in case my DeWalt router is not up to the task. And I needed an excuse to upgrade :grin:. Before I click “start job” I wanted to tap the knowledge here and see if anybody has done something similar. During a cursory search I saw a story where a guy was cutting copper and he was burning up his bits somehow (story follow-ups with success are lacking) and I’d really rather not do that. So I have the following questions for anyone who has successfully cut copper sheet on their Shapeoko 3 XXL:

What bit did you use successfully?

What were your feeds and speeds?

Any words of caution?


I did a test a while back on a thin-ish copper sheet for someone.
Decent results from the 1/16th endmill with a stepover of .118 inches and depth per pass of .006 inches.
Plunge of 6 inches and feedrate of 10 inches with 24000 rpm.
This was done on the nomad though.
Sheet was .04 inches thick
Winston has a few videos that I referenced (probably stole the feeds/speeds entirely):

You should be able to hit those numbers with the shapeoko 3.
One thing I found is the edges looked a bit rough. I think I either sanded it down after cutting things out or maybe ran a very small depth contour pass with no offset.

The antenna features were too small, so they ended up not surviving well.
This was quite a while ago (a bit over a year ago), so I don’t recall any other specifics.


Thank you very much. That was most helpful.

I think you will have real problems with hammer soft copper being gummy. And I guess the harder tellurium machining copper won’t be any good for gasket material.
Maybe mill a punch and die and stamp out the cooper instead?

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That would be a preferred option, unfortunately they’re not available to me. Lots of WD40, air assistance and some slow feed rates is going to have to do.

I have not tried this but Chris Fitch from Woodsmith magazine has a video series called CNC basecamp.
He has one where he does thin metal inlays.
Cnc basecamp ep 006
One technique he used was to glue the metal sheet to a sacrificial mdf board with liquid hide glue. When he was done marching he soaked the assembly in water which released the metal piece, since since hide glue is water soluble



I will have to look into this. Thank you very much.

I wonder if the C3D drag knife would work? I’ve cut aluminum foil with one.

This material is around 0.070. Probably a bit much for a drag knife.