5W laser, burns the wood instead of cutting it

I have had a simple 5W diode laser for about 2 weeks. Unfortunately, I can’t manage to laser out fine details… Whenever it’s a little smaller and it’s lasered, it ends up being just a black spot and you can’t see anything. I have also increased the speed and decreased the laser power, but I just can’t get it to work, because I also want to laser through the board, so I need power. Do you have any ideas?
Thank you very much!

engraving layer: focus the beam, do some tests starting at low power and slow speed until you get the result you want and then increase the speed by 10mm/s or so and step up the power til you match what you got at low/slow.

cutting layer: focus the beam to the middle of the wood, do some tests starting at high power and slow speed until you get the result you want.

In both cases you must have something blowing the smoke away from your laser lens or else that smoke will go straight up onto the lens and it’ll either damage it or need cleanding constantly.


Also a diode laser really benefits form an air assist for cutting.


In the sample burn picture above, did you notice the vertical lines are thicker than your one longer horizontal line? Lower end diode modules won’t have multiple lenses to correct for the physical characteristics of a single diode element so the “dot” is really more of a small rectangle. This effect will give you better cutting on horizontal lines and less cutting effect on vertical lines.

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At this point, follow @dougl suggestion, do a ramp test to ensure you know where the focus point really is… many times the manufacturer isn’t quite right… :face_with_spiral_eyes:

If you use Lightburn, it has Laser Tools → Materials Test where you can try many variations of speed/power/interval quite easily to determine the best to use on a particular type of material.

This is the materials test on a stainless steel dog tag … This uses a fill type, but you can just cut out the boxes. Probably what you want to do to determine cut data.

I almost always raise the material above the table.

I try to just slice a small piece off the end… That allows me to see a cross section of the cut, not a black hole… If you can see what’s happening, you can probably envision a cure.

As @NedMan mentions air assist, I will expand it’s scope to include most cutting operations. I use a very low pressure to cut acrylic…

This should get you going… Good luck


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