Found some basalt tiles at HD, testing on some mineral-oil covered stuff yielded the following at 225 LPI. First two columns are 1 pass (905s 30p is at the top and 600 30 at the bottom), and rightmost column is 2 passes.
This is a “good” shot with a good reflective angle on the light.
This is a “bad” shot looking straight at the material.
I’m probably going to write this one off as an engraving material (still would work as the base for a tape stencil as it’s very flat, albeit porus). Without the mineral oil (and really even with it) there’s basically no visual contrast.
Just got my glowforge a few days ago and I’m already burning through plywood - love how easy this machine is to set up and use (I’ve had an X-Carve for a long time and there’s nothing I hate more than zeroing the bit and removing tabs).
I had a similar fail at basalt. It melts more than anything, not a good looking engraving material.
Now I use the 3x5 (ish) basalt tiles that I purchased as weights for gluing and miniature “anvils” for when you need a perfectly flat surface.
Here’s a screenshot from a Trotec video on basalt:
They mention they had to increase power to get the white mark. No idea from what to what.
Thanks testing this out and sharing your experiences.
If basalt is similar to slate then depending on the source, engrave quality could vary quite a bit. I have slate that is gorgeous, and slate that is worthless.
I’ve experienced the same. In my reading, the source of slate is important and the stuff from Germany is the best for engraving. Not sure how you know what the source is though.