Odd thing about this print: the left/right edges always come out really dark when compared to the center fill. I ran an approx 50mm square print on 6.35mm thick balsa wood, using 100% laser speed and 625mm/min working speed. It came out pretty well, though only the “1 px” thick sections (left/right thick) were nice and dark. I may need to reduce power and turn down the feed rate, but I think the problem comes from the way Luban makes tool paths in Black & White mode. Each of the rows (shown in the second image in my previous post) is cut first left to right, then up a row, then right to left. At each U-turn the beam is closer to the previously cut area than when it’s traveling in a straight line, so it heats up the material there more. This could be resolved through a few methods without substantially increasing print times I think.
If you number each row, starting from the bottom (as is the default) and cut row 1 left to right, then say… row 5 on the returning right to left cut, and always make sure that the last row is a few away from the one you just did, I think that’d help quite a bit. At the start and end it might have to take a few inefficient rapid moves to make this happen, or dwell for a small period of time for the material to cool, but overall the increase in time shouldn’t be too bad, and the consistency of the result should be well worth it.