What is causing this during engraving?

Machine: K40

Board: LaserBoard

Firmware: _Smoothie

Problem/ Question: so since switching to the cohesion3d board I’ve been having issues with engraving quality. It seems the laser will forget to engrave little slivers. Today’s was the worse yet. Spots missing all over the place. The S in the photo is all uneven and the letters in the other photo are wobbly. I’ll include the confit file tomorrow but my x current is .6 my y .8. I dropped max down to 20000 and acceleration down to 2000. I ran the engraving at 240mm.

Hi Steven,

Thanks for the photos and information.

Great, this will help!

What are the specs on your stepper motors? You may need to increase your current if you are using the onboard drivers. More information: Changing Stepper Motor Currents

Which max parameter did you lower?

You can try lowering even more to 1000-1500 and see if that helps. Keep adjusting until you get it dialed in. If all of these changes do not help, it may be a mechanical issue. We can work from there once we have more info.

Can you also provide screenshots (no cell phone pics, please) of the entire LightBurn window and the layer settings for the file you are working with? Do you have Flood Fill enabled on the layer Cut Settings under Fill Settings?


This uneven banding is sometimes present in wood when engraving, due to the grain. Try doing a test engraving against the grain of the wood and see if you get the same results.


Yes I did have flood fill checked. Is this a bad thing?
Here are the photos of my settings and config file. Sorry I just put the config files as JPEGs

![Whole Screen|690x414]

Also, I have tried against the grain and it comes out the same. Mainly, the missing little slivers. I have each portion of the design grouped to try and keep the laser doing one section at a time instead of jumping all over the place.

Try again with this setting disabled. Flood Fill will skip sections and comes back to fill them later, so you will sometimes see gaps. It’s mostly used designs that have large open areas, like a frame. The gaps may be visible if you look at the Preview window and use the slider to see where it plans to move the laser before processing the job.

Your config file settings for the stepper motors looks good now. Just make sure your stepper motors are not getting hot.

Try lowering the power setting on the layer some to try not to engrave so deep into the substrate. Keep tweaking until you get it dialed in. If this is a birch ply, some of them are made with a pretty thin surface layer with other woods sandwiched between.

Do you have air assist installed? If not, that may be something you want to look into getting.

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