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?

Thanks.

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.

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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

John

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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.

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