V-Carving Granite

[jimmya]

Has anyone cut Granite on there Bot? I have a customer that wants a sign V-carved in Granite, can it be done?
Jimmy

[cabnet636]

there has been some disscussion on this on vectrics vcarve forum

jim

[dubliner]

It will cut marble, Granite will definitely be harder on your bits. Granite melts teeth on a rocksaw, so I could only imagine what it might do to a delicate edge carbide bit.

[rcnewcomb]

We have tried granite and it just melts solid carbide bits. At the very least you would need a diamond bit. Check out Diamant Boart at http://www.dbstone.com/pdf/2008_Stone_US.pdf

You can cut marble, limestone, and soapstone all beautifully on the Bot with a solid carbide bit..

If it MUST be granite then I'd pass on the job.

[jimmya]

I thank all of you for your feed back. I think I will pass on this job or see if he could use marble.
Thanks again
Jimmy

[zeykr]

Jimmy,

Cut sandblast mask with your shopbot and have a monument sandblaster blast it for you. It will look vcarved and you can get pretty detailed.

[jimmya]

Thanks Ken
I'll check that out and post back, to let you and others know how it came out.
Jimmy

[nappy1]

Jimmy,
I work with Granite on my day job. It requires diamond tooling and a lot of water. My opinion is you can't do it on a non stone machine.

[laserguy]

In addition to the above, the physics behind V-Carving itself makes the process even harder than with just about any other tool due to the physical bit geometry.

As the Diameter of the (any) tool becomes smaller its surface to surface contact and actual sfpm (surface feet per minute) that the cutter maintains against the material becomes much lower. which means you would have to run slower feeds and/or higher rpms to maintain enough SFPM at the tip to actually cut the material without placing undue pressure on the bit and breaking it. But, doing this also has the added detriment of making the larger Diameter of the V bit cut too thin building friction and heat exponentially.

In short, don’t do it. Physics says it’s a bad idea, and physics is always right. :D