Hi, my name is Chris, I’m from Styria, and until I moved, I only had diode and CO2 lasers – no problems there.
Now I have a Commarker B6, 60W MOPA (with an F210 lens and a 150mm x 150mm working area) and for years, I’ve managed to silently follow along, but now I have a problem I’m not quite sure how to solve: a visible “grid or pattern” in engravings.
I mainly wanted to engrave brushed/ground brass. The grid is sometimes more, sometimes less noticeable depending on the depth of the engraving. It’s most noticeable right in the middle of the working area (like centering a cross).
I don’t know if this helps with identifying the problem, but the rectangles are 2.5mm x 2.5mm in size.
Settings: 1500mm/sec, power 55%, 450 kHz, 13ns, line interval 0.002, 1 pass, scan angle 0 degree:
200mm/sec, power 95%, 60kHz, 200ns, line interval 0.025, 4 passes, scan angle 45 degree:
With the deeper engraving you can clearly see and feel that the engraving is less deep.
The pattern is most visible when I use scan angles of 0, 45, or 90 degrees for a single-pass engraving, and is no longer visible if I use a scan angle of 6 degrees, for example.
With deeper engravings the lines are always visible.
Scan angle 6 degrees:
All templates I have tested are vector files that I created in Fusion or Illustrator, but even when I test with squares created in Lightburn, the result does not change. I also used a fresh Windows 11 and a freshly installed Lightburn, nothing has changed and used Lightburn versions from 1.7.0.8 to 2.0.04.
As a test, I have already switched to EzCAD and the problems/patterns do not occur here with the same settings as in Lightburn.
I hope you have an idea what’s going wrong or can point me in the right direction. I’d hate to give up the convenience of Lightburn 
Many thanks in advance!