It does not appear that you are doing anything wrong.
It appeared to me that problem is similar to this and this.
Have you tried on different material? Cardboard, MDF, plywood? Same pattern?
In addition to my speculation in other two threads, this one appeared to have a power sag: lead in on the left is burnt significantly more than the rest. I would think that your test is done as a raster and single direction, from left to right. Power appeared to sag after initial load/left lead-in, and then beat between laser PWM and PSU PWM.
It also appeared to me that your cabling is too thin and too long for 10W optical/50W+ electrical.
To try:
- Better, more powerful (100W?) PSU.
- Fiddle with $33 setting, see reasoning in two threads I’ve referenced above.
- I would definitely try to bypass that long thin wire, even if it s a factory cable. Make your own, larger gauge, calculate wire resistance or measure (with full power ON, be safe! Maybe use equivalent dummy load) to have a voltage drop <0.2V under full load. Or get separate PSU for the laser only and wire directly to the laser head.
That lead in is main indication that power at the laser is unstable.