Tools for machining solid carbon (not carbon fiber)-more posted

[camcutter]

Hi there,

Does anybody have experience cutting carbon. I'm talking about solid carbon, not carbon fiber. There are many different grades but mostly the problems I'm having are with chipping and tool wear as it's very abrasive. Do you recommend slower speeds and higher feeds or faster speeds and slower feeds? Faster spindle seems to dull the tool quicker (rounds the edges) and slower spindle seems to chip the material. Using diamond roughers and diamond coated tools but price is sky high. Any suggestions??

[svenakela]

Chips? Nah, rather dust. I've been using high speed AND high RPM, but I didn't pay the mills though, it was always diamond ends.

[cb1]

diamond coated tools are the way to go.
the prices are huge like 125$ for a 1/4 endmill.
they should last and last and be well worth the money
if you are running them right. my local supplier is CVD in London Ont.
Canada
svenakela is right high speeds and feeds like over 10,000 rpms
maybe close to 30,000 if you can get it.

[RICHARD ZASTROW]

You will need a dust collecting system, some sort of breather, filter respirator thing and a lot of soap. Personally, I used a lot of "Protek", that lotion type stuff you rub into your pores. It helps washing-up after cleaning up the area & machine. In reference to your original question, it was answered above. Also, plan your cuts to avoid the breakout at corners, even if you may have to come back from another direction. Happy dust cloud!

[camcutter]

Ok, thank you for the replies. Let me ask you a couple more things then.

I just started working with this material and I'm using the diamond "grit coated" cutters (or whatever the proper term would be) for roughing and have limited access to diamond coated finishers, but mostly uncoated carbide for finishing. All 2D parts, pockets 2d contours and such, no 3d shapes. The max spindle I can run is about 7000. For lets say a 1" rougher, what would you recommend for cut depth and stepover and such? Am I better off taking many .010" steps or 1 giant step? Go to depth then use small xy steps? I'm starting from ground zero and totally confused with this stuff. I've cut different materials before but this stuff is really tricky. Hats off to anyone that has this material conquered!

By the way the stuff I'm cutting now is EK20 if anyone has worked with that. The part is about 5"x5"x.200 with some shallow pockets and a couple 1" bores through. Anyway, thanks a lot for your advice

[RICHARD ZASTROW]

You may want to look into Severance Tool for carbide "diamond cut" burrs/endmills/routers.
ADD: cvddiamond.com diamond tool supplier, pricing?