Primers on cutting carbon fiber?

Any good primers on cutting carbon fiber?

I’d like to machine 3/16" thick stock, I’m curious about whether I can use a rather conventional spiral bit, the bits I’ve seen being used seem like the same sort used for cutting fiberglass, they have chip breakers that seem to leave a poor finish when used on wood.

I’m also curious about things like tabs, if I leave a tab can I cut through it and sand what remains flush with hand tools? I’ve never worked with carbon fiber before (can you tell?).

Any good threads or sites to read, I’d be thankful.

There are some notes/links at:

I cannot speak to cutting CF/FG with the Shapeoko, as I have not tried it on my machine yet.

However, you can use a variety of tools to cut CF/FB to finish those tabs. I have used table saws, miter saws, dremels, etc. Just use a correct saw blade, such as something with a high tooth count. You can also sand it like you would any other material. However, it is important to use protection against the dust, it is extremely bad for you. Use a mask at the very least, I would recommend a respirator with the appropriate filter. You can also gain skin allergies if you are exposed to it for a while, use gloves, wash y our arms hands, shower, etc. BE SAFE.

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Here’s a couple Phil.

End mill recommendations included.

Tape and glue for work holding, no tabs necessary.


I had great success without much trouble. Used a 2 flute endmill and fairly conservatives feed/speeds close to plastics…fast feed, but low DOC. Endmill wear was measurably faster than most materials. Double stick or painter’s tape and CA glue worked well.

I will echo the comments on dust safety. That stuff is akin to asbestos in your lungs. I work with it at the day job and they have paid millions for good dust collection. If you have a shop vac with a HEPA filter, use that. If not the water bath works, but keep the steel pieces protected as much as possible.

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Thanks everyone for your help.

I normally clamp my workpieces, does the masking tape + glue method foul the bit, if one cuts through the material? What are the best practices for tape + glue?

The tape can foul the bit. I’ve probably 12 hours of CF cutting at this point so still a noob.

My experience thus far: any given cut takes at most 15 minutes to complete. For a clean edge you definitely want to cut all the way thru the CF. I challenge myself to cut through only the first layer of tape to minimize fouling. Between cuts I squirt some acetone on a toothbrush and clean the endmill. Of course, being lazy and human I’ve forgotten this step on numerous occasions but I haven’t noticed any change in cut quality.

The $1.80 mill I referenced in an earlier post def cuts CF better then any standard mills I tried. Once I quit breaking them by being too aggressive.

Trying some chamfer tool paths now with cheap Chinese “diamond” coated bits. Very poorly balanced, do not exceed 6000 rpm.

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Thanks, Griff.

Can I do tabs with Carbon Fiber? I guess the question is, can I cut the tab with a knife and sand the nub off, or is that difficult with carbon fiber?

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I used tabs on a few pieces. I cut them off with a dremmel and hand sanded.


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