Granite

[Keith Hodges]

There has been numerouse post over the past 3 years concerning carving on granite. The general consensus is that it can't be done without some very expensive speciality bits, and tons of granite dust clogging your lungs and bearings on our sharks. I had some granite sink cutouts and cutoffs given to me, but was discouraged by what I read, so I just placed them in front of my shop steps for an additional step. A friend doing laser engravings in granite got me thinking about granite again. A utube video inspired me, so............

[basecircle]

Hi Keith Looks like your using the Diamond drag trick on that granite.Looks good very good .I like it. Basecircle

[Keith Hodges]

Good eye Basecircle. The Diamond drag bit is the best thing since I discovered this whole CNC thing.

[Keith Hodges]

I discovered that the granite was not flat. A little thicker on the right side, causing the drag bit to not lift completely off the surface. You can see the line from the right going back to home position. So, some checking for flatness is necessary. I didn't know how to change my safe Z height, so 4Dthinker helped me out. Changing that, I was able to adjust the height of Z0, and get the bit to lift just enough to clear the surface while moving from one carved area to another. Granite takes quite a bit of pressure to engrave, so the bit had to be compressed about half of its compression travel. First attempt with it barely touching the surface for Z0, didn't even scratch the surface. All in all, another fun learning experience. Don't know how far I'll take this, but just knowing I can makes it worth the effort. Oh yeah, forgot. All the worry about dust. May be a problem with a v cutter, or something with the router running, but with the diamond drag bit, there is next to no dust. Just a small spritz of plain water on the area being engraved is all you need, for lubrication, and to control any small particals dislodged by the bit.