Black dots issue

[thejake (Jake)]

Hi there,

Can anyone tell me why one of my two the same laser, both working on LightBurn is leaving black dots like on the picture?

The issue is only in FILL mode.

Thanks!

[berainlb (PY)]

The edges are likely burning where the laser is decelerating/accelerating on the edges.

I’m not familiar with your lasers but this is typically mitigated in a couple of ways:

1. newer versions of GRBL 1.1f+ have a laser mode that allows for variable power. You will also need to be using the GRBL profile in LightBurn for this to work and not GRBL-M3 or other.
2. Overscan mitigates this effect by running past the leading and trailing edges of the burn allowing for time to decelerate/accelerate.
3. Also make sure you’re not using “Constant Power Mode” in the cut settings as that negates variable power.

So I suggest:

1. Check that your firmware supports variable power by running $I in Console. It needs to be at least 1.1f.
2. Check that your device is configured as GRBL. Click Devices button in Laser window. Then click once on the name of your laser. Device profile is listed at bottom of that window.
3. Disable Constant Power Mode
4. Enable overscan in layer settings