do you know why when you cut in one direction (green arrow) it doesn’t get dirty and when you go back (red arrow) it gets dirty?
Without knowing anything about your system or circumstances I can say that one factor is potentially the result of your fume evacuation strategy. I’d assume you’re getting easier and more consistent fume extraction while moving down where the smoke doesn’t have an opportunity to resettle onto the material.
In the other direction it’s possible that something is impeding airflow and as a result allows the fumes to resettle onto the surface.
I had similar problem when the air assist was only a thin tube pushing fumes away.
The laser will traverse the red path in both directions unless:
-
Optimize Cut Path
is turned on -
Remove Overlapping Lines
is turned on - The lines overlap within the tolerance distance
If your “larger” laser is a CO₂ (typical for a Ruida controller) and the material shifts slightly after the complete perimeter cut, then it’s charring the edge of the shifted material.