I have a “Fill” layer, “fill groups together,” with a 2mm Z offset. Device is set to “Enable Z axis” and “Relative Z moves only.”
If I have 2 or more groups to be engraved the first engraves as expected. The 2nd and subsequent groups engrave much slower. I think it’s pausing between each letter in a group of letters. This results in much slower operation and a lot more power being burned into the material.
EDIT: When you turn off “Enable Z axis” it works correctly as expected.
Reading the Lightburn docs, it’s not clear how to use it without “Relative” set.
Enabling Z control means that LightBurn will always emit Z values for a running job, and therefore requires that you set either the “Relative Z moves only” toggle below, or a material height value on the main cut panel. If you to not set relative mode, and do not set a material height, the default of 0 may cause LightBurn to raise your bed to a point where the workpiece could contact the head of your laser.
Where or how do you set the material height?
I’m only doing this to help gather info and narrow down the bug. If I have to set material height for every job, 99.9% of which don’t require Z movement, I simply won’t do it.
Even if this machine requires absolute Z positioning, I don’t think anyone can argue with a straight face that this is expected or desirable behavior.