Fiber laser hatch fill not smooth

Hi guys,

So I picked up a 30W fiber laser and have been experimenting with it. I'm trying to put solid black marks on some connecting rods but getting weird results where half the hatch is nice and smooth and the other half has some random deep grooves.

Attached is an image with my test marks, the #2,3,4 from the left look good but half of the circle has deep scratch like marks for some reason.

Has anyone seen something like this? There's so many possible settings in EZCad I'm not sure what to try.

Speed: 100
Power: 80
Freq: 40
Line distance: 0.04 mm


Thanks