Dots that are not visable in the previeuw

Why are these dots appearing in the burning on my mirror.
How can i avoid this?

I see no dots or any image …


We can’t see what you see, so post a photo…

:smile_cat:

dots

Perhaps you (inadvertently) activated OverCut so the laser is retracing a small part of the path start:

https://docs.lightburnsoftware.com/UI/CutSettings/CutSettings-Line.html#overcut

It’s also possible the machine has a small amount of mechanical backlash, so that the laser beam does not start moving at the very start of the line after arriving there from a different direction. A careful review of all the places where motion may occur when it shouldn’t is always a good idea:

https://diode-laser-wiki.com/documentation/guide-to-mechanical-adjustments/

That’s for a different brand, but you’ll recognize many of the parts and see examples of what can go wrong along the way.

1 Like

paw.lbrn2 (44.7 KB)

Our machines start from different corners, so the paths are different, even with optimizations turned off.

The paths do not have nodes in the places where those spots appear, which eliminates my idea of Over cut being turned on: the paths do not start in those places.

Similarly, mechanical backlash occurs only at direction changes, which cannot happen between nodes.

Watching the Amazon video suggests the bulky cable loom between the rear rail and the laser head could snag on the gantry, which would be enough to jostle the beam.

Make sure that arch of wiring does not touch anything, no matter where the laser head moves on the platform. Perhaps hold the loop up while re-running that pattern to see if that changes anything.

There is nothing touching so there must be another explanation
Wich video are you referring to?
I have a Ginmitsu Gensoku LC40 20 w

Even on a cirkel or a square it shows see picture

vierkant cirkel

https://www.amazon.com/Genmitsu-Engraver-Engraving-Assembly-Movement/dp/B09TKTJB9Z/?th=1

The first video shows that coily cable flopping perilously close to the gantry & laser head.

If it’s not that, then I’m out of suggestions.

Could it be the beginning or the end of the burning of the square and the circle. Something to do with the begin or end power of the laser?

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The scorches in the shield do not seem to align with any of the nodes in the curves, which is why I doubted that was the cause. The square provides a different test, because it definitely has a node at each corner.

All of the scorches appear in the lower right quadrant of the patterns, which suggests a common cause.

@berainlb may have better suggestions than I at this point.

I hope someone can solve my problem

Try disabling constant power mode and retest.

Also, can you confirm whether or not this only occurs with mirrors or does this occur with other materials as well?

it does the same with acryl

in cutting settings there is no box with constant power to check on or of

no power check on or of

Can you do the following:

  1. With design loaded go to File->Save gcode
  2. Save to file with .txt extension
  3. Upload file here

I suspect you’re using an incorrect device profile.

paw.txt (19.7 KB)