Spots appear at the intersection of the lines

min power being set too high can do this. As it slows and reverses, it’s not throttling back the power enough

It must (almost) stop before changing direction, which means the controller must reduce the power as it slows to produce the same effect on the material. As Kevin points out, the Min power setting for that layer is too high, so the controller can’t reduce the power enough at the lowest speeds.

However, ordinary DC-excited CO₂ laser tubes won’t ignite below about 10% of full power = full current, which means you can reduce the layer setting to the point where the laser won’t fire in the corners.

Amusingly, the firing behavior depends on both the Min and Max power settings, the cooling water temperature, and the laser path through the pattern.

• Durell

  : Thank you for your support. I will give that a shot.