The most obvious cause would be not applying the Scanning Offset Adjustment:
A single switch turns that on and off, so perhaps it was inadvertently clicked at some point.
If you’ve never measured / filled in / applied that correction, doing so will almost certainly improve the situation. The values depend on the speed, so measure the offsets between 100 mm/s and 500 mm/s, at 100 mm/s intervals.
If you have previously set up that table and it’s still enabled, then something mechanical has gone wrong. A CO₂ laser may have developed a loose screw in the belt anchors, a loose mirror mount or focus lens, or perhaps a pulley mount on the X axis.
Hello Ed, thanks a lot for your insights! After multiples material test settings and manual changes of the line interval, power, x acceleration, etc. It turns out simply adding a Scanning Offset Adjustment (SOA) did the trick.
We can truly see the difference in quality when using and not using the SOA correction!
I would have never found this myself, thanks a lot!
I’ve made very similar cuts in the past with this machine in the recent months and there was no need to input this information to have a qualitative print. Could it be due to Lightburn software update? Or maybe I changed some settings by inadvertance?
Here is a close up of the prints with and without the SOA :
The offset depends on the speed, but the visible result depends on the material and how fussy you are.
The size of the entries in your table says you must measure the offsets at speeds between 100 mm/s and 500 mm/s, at 100 mm/s intervals.
If you have some acrylic lying around, it’s easy to measure the offsets. These are 1 mm squares on fluorescent / edge-lit acrylic, before and after correction:
