I am playing with a laser cutting/engraving machine. There is a small wedge with the machine, with 3 widths, each width having a text on it :
- cutting 7mm wood (close to the surface)
- cutting 5mm wood
- engraving and cutting 3mm wood (far from the surface)
It allows you to set the height of the laser. I try to understand what would be the best setting to engrave rock. I understand that to etch on wood, you want a large laser to burn it instead of vaporizing it. There are even toturials on defocussing the laser to get better blacks (larger laser, more burning, less vaporizing). Random example : https://www.youtube.com/watch?v=Xcg1y2cQl-o
Now, I want to engrave rock. I don't want a larger laser. I want the hotter tinniest spot on the surface of the rock. I start to get great results on black rock (1000mm/s, 10W, 3 passes).
To get the more focused spot, should I go with the setting close to the surface "cutting 7mm wood" or with the seeing far from the surface "engraving and cutting 3mm wood" ?
Has any of you tried to engrave rock ? Do you have tips ?
Thanks. Actually I tried mnémotechnique settings and the focus does barely nothing. At least compared to speed and power. And even to precisely etch wood, I can't distinguish any variations of focus. The laser beam is really thin.