I’ve noticed that these marks appear when I use the trace function on a black/white bitmap image. So the result is a vector that does not show these marks even on the max zoom and these marks do not appear in the preview.
Tried the original RD studio and that one does not seem to have the issue.
The rolling cloud shape of the top edge of the dots on the old thread is likely caused by an image processing approach called dithering - the shape of that line and the reasonably straight edge of dots along the bottom row is a fairly solid tell.
It will show up in the Preview window because the laser is being called to fire by stray graphic information.
I looked at your project in the Preview window in LightBurn and there is no stray graphic information in your project to cause the same problem.
Can you tell me more about your laser engraver and the material you’re cutting?
Are the stray burn marks deep or just barely on the surface?
It’s possible this is a communication error between the computer and the laser, but more often when I see this pattern, it’s electrical noise. When running a fill, the laser is enabled for the whole run, and the only thing changing is the power level, and that is handled by an analog or PWM wire between the controller and the laser power supply. If any electrical noise causes stray current in that wire, you’ll get random firing like this.
I’m questioning if this is the root cause in this case though since @Potven says he can do this in RD Studio without the issue. Doesn’t seem likely that the electrical noise would be different between programs unless somehow the settings from LightBurn create a different set of variables where noise is more likely.
Without seeing the files sent on both systems I can’t say for sure. It could be a settings issue - Whenever someone says, “It works fine in RD” my next question is, “were the settings absolutely identical?” and the answer is rarely yes.
To @Potven - If you save an RD file from RDWorks and send it to the laser with LightBurn do you get the stray dots? If you do it the other way around are they present?
Somehow shield and cable manage the relevant cables and see if that helps (true they are pretty close together and some interference might be there but interestingly enough I can see this issue only on some of the work but there it is always)
Replace the EMI filter on the main power (may or may not be related)
Recreate the file completely in RD works and run it again
3a. Run the RDworks generated file through LightBurn
Ad Material) This is something called washpaper/ special kraftex paper and is used for clothing labels as a replacement for leather
Ad Marks) These are barely on the surface just color change due to short heat I guess no depth whatsoever (so this really might indicate a stray induced current somewhere / electrical noise)
Ad laser) This is homemade version based on y400 from Rob/FurtherFabrication.com (reasonably customized and upgraded based on Ruida 6445g / 45w tube/ but there is a 100w PS)
