Been having this same problem for a while now. Laser is cutting fine across 85% of the bed, but as soon as it gets to the lower right corner no amount of power or speed drop seems to help cutting even 7mm plywood. If i cut a batch of coasters out of 600mm square 7mm thick piece of ply i have at least 10 i have recut. And even then most times i have to break them out. Mirrors and lenses are all clean and well aligned. The z axis has been checked and calibrated with feeler gauges on all four corners and is accurate. Ramp test showed my clearance is spot on. So im left wondering what the hell is goin on. Any help greatly appreciated.using lightburn. Machine us a chinese blue and white 100watt co2 with a ruida controller.
As I see it, it’s glue pockets. I just figured that 100 Watt could handle it, but it can’t.
You write that it’s more pronounced on one side of your machine bed, which suggests that either your bed is a bit uneven, i.e. the focus is not the same over the entire area, or that you “just lose” a little power in this area, which is normally the furthest from the tube.
But with the pictures I see, I’m inclined to think that it’s bad plywood. The dark edges also indicate that. The cut edges should be light brown, honey-colored with 100 Watt.
Find a piece that you can’t cut properly, place it somewhere else on the bed and try to cut where it’s darkest and you could only break it and see the result. The pockets are anywhere from mm to cm in size.
Consistent focus, clean optics, and alignment would be the first things I’d check, but looks like you have already done that.
The only other thing I would say (even though it should be part of the alignment) would be to confirm the beam from M3 through the nozzle remains centered as it passes through the nozzle in all areas of the bed, (low power pulse on masking tape at the nozzle end and check the hole it’s concentric to the outline of the nozzle end). You can lose a lot of power with a slight drift in alignment with some of the beam clipping the side of the nozzle.
Also is your extraction good? a smoky enclosure will absorb and scatter the beam, and this may have more effect further away from the source.
