Machining concrete

[preciseformwork]

I'm thinking of building my own 3 axis cnc router and using it to engrave concrete.
I would've thought it would be possible with high-quality diamond bits. I would think it would probably eat through a few bits. Anyone experienced machining concrete like this before?
I wonder if a laser would be better though not sure if a laser would be able to cut concrete, possibly high pressure water jet? Any input on this specialist area would be appreciated.
Thanks.

[ckelloug]

I've successfully machined an epoxy granite plate much harder than concrete using Cubic Boron Nitride TNG322 inserts on a Bridgeport mill. 32 square inches of machining was enough to wear out the inserts for the most part.

Diamond is probably a good choice or CBN. Anything less will probably have a very short life. Make sure to collect the dust as it will eat machines alive.

--Cameron

[preciseformwork]

Thanks for your input ckelloug, wow sounds like get through a few bits then. Do you have any pics of your machine. Did you build your own machine? I imagine it'll be a lot of work and worried about the time it'll take.

[awerby]

if you can possibly avoid it. A router design won't have the rigidity necessary for stone work - check out Bavelloni and other machines built for this purpose - they are extremely heavy-duty machines made to work wet, with well-protected mechanical and sliding parts. The tooling won't last very long at all, and it's quite costly.

If you want concrete parts with engraving or whatever on them, use your router to carve molds (in reverse) and cast the concrete into the forms. If that's not possible for some reason, then cut stencils and use abrasive blasting techniques to remove the material - it's a lot quicker and more cost-effective.

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

Originally Posted by preciseformwork I'm thinking of building my own 3 axis cnc router and using it to engrave concrete. I would've thought it would be possible with high-quality diamond bits. I would think it would probably eat through a few bits. Anyone experienced machining concrete like this before? I wonder if a laser would be better though not sure if a laser would be able to cut concrete, possibly high pressure water jet? Any input on this specialist area would be appreciated. Thanks.

[ckelloug]

Hi preciseformwork,
I was machining a test sample of material that wasn't quite in the right form to test it. I wish I had constructed a machine by now but I'm obsessed with the material design since it has broader implications than one machine. I did the work on this material sample at max speed for a generic worn out bridgeport mill with a two insert tool.

I'd go through quite a few CBN bits at unrealistic cost if I tried to machine material this hard regularly. I tried it because I had a few CBN inserts left over from a job that didn't materialize.

I'd figure if you had a diamond bit that you could probably engrave on concrete but I think awerby looks like he has some good advice.

--Cameron