Laser greyscales

Tuning my laser setup on the LR2 and I tried doing the Garfield greyscale and a photo I flipped to greyscale in GIMP. I used ImagetoGcode_V1.3 with my burn speed set at 31 here are the results:

And I ran Ryan’s 37mm_smooth gcode and obtained these results:

Suggestions for improvements please…

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I’m not familiar with these tests. Do they adjust z-height, laser percentage, or machine speed?

Did you focus the beam of the laser before running the tests?

Going slower would make them darker.

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Beam has been focused and these aren’t true test files just greyscale images I am trying at various speeds to see what works. I’ve got to hunt down some solid test files to help me tune speeds and strengths better.

Ah. In that case…

The two big things that will affect laser burns are the burn speed and the laser strength.

Since you’re wanting to do greyscale, you can’t really just ‘increase’ the laser strength, so your only other option is to slow down the speed.

What power laser did you go with? I have used two, a 3w and a 7.5w. The 3w had to run at a pretty slow speed for most burns in wood to get a good darkness.

To some extent, the stepover will affect darkness too, but mostly only affects burn time. I think LightBurn likes to start with a .1mm stepover. Which looks really nice, but takes Forever to run. Most burns I do now I run at .2mm or .25mm stepover. Your laser strength can affect this too as more powerful lasers typically have a wider beam. You can get away with a slightly larger stepover.

It’s a 15W eBay special. I suspect it’s really just an overdriven 7.5W. I’ll try running the same images through Lightburn and tweaking the stepover and speeds and see what I get.

You’ll want to do some more research on that laser.

My 7.5w laser was marketed as a “30w” laser. The 30w referred to the wattage of the power supply and not the wattage of the laser.

I’m betting your 15w laser is really a ~4w diode on a 15w power supply.

Here’s a good article discussing the laser: