As soon as I put the Ortur 2 together, I figured I would try an easy test: cutting white paper.
I adjusted the focus to have the sharpest possible dot on my piece of paper, but I could barely get anything out of it.
I switched the lens with a G-8 lens and managed to cut paper. But the parameters seem to be off compared to the ref table I got from Ortur:
The minimum speed/power combinations are as follows:
a) 800 mm/min 55% power
b) 1000 mm/min 70% power
c) 1400 mm/min 100% power
Am I missing something? Is there a setting I missed in Lightburn?
The key here is white paper. You have a visible light laser, which is strongly reflected by white surfaces. Try darkening the paper, or using off-white, or better still, colored paper. It will absorb much more of the laser energy.