Well, I ordered a diamond drag bit, and I picked up some black granite floor tiles yesterday. All I have left is figuring out what on earth I’m doing, eh? 
I’ve got my artwork into a nice SVG, as I’m doing a laser engrave on some bamboo cutting boards. I did all the toolpath work on that in LightBurn, which makes it really easy to define fills (line or crosshatch). Now, I just have to do the analogous thing for a diamond drag bit. Carbide Create doesn’t let you define fills like that, so it’s out. Vectric V-Carve would send the project way over budget. It’s possible to bodge virtually anything with enough work in Fusion 360, but that doesn’t seem the most effective approach (and I don’t have enough time left before Sunday).
So, looks like my options are either settle for whatever fill I can get out of Carbide Create (although it will not please my artistic sensibilities) or splurge on V-Carve (although it will not please my budget)… or…
If I use LightBurn to generate “laser” G-code (no overscan, 2D), then convert the “dark” (S0) moves to “raise the spindle, move, lower the spindle”, that seems like it should get me just what I’m looking for. I’ll just have to run one little regex (match: “^G1(.*)S0$
”, replace with: “G0Z5\r\nG0\1\r\nG1Z-5F750
”) and do a quick hand edit of the beginning and end of the file to get things ready.
Well, tonight’s laserin’ time, but I think I’ve got a plan that may be up to scratch for diamond drag bit engraving. (Looking through threads, it looks like starting numbers that should work are around ~2.5mm spring compression, 750mm/min plunge, 2500mm/min feed, and a spritz of water.)
On further review, two regex replacements (and then fix just the header):
- Search:
^G0(.*)$
Replace: G0Z5\r\nG0\1\r\nG1Z-5F750
- Search:
^G1(.*)S0$
Replace: G0Z5\r\nG0\1\r\nG1Z-5F750