I used to have this but I’ve built a separate CNC machine for lasering and engraving: printables.com/…/1071387-ender-5-x-mgn12-detachab…

Do I recommend building it? Eh, it will work but there are some issues. 3D printer controller software such as Marlin or Klipper also does not play well with applications like LaserGRBL, Lightburn or Rayforge. They are designed with GRBL in mind or other dedicated CNC controllers. The 3D printer approach used the part cooling fan to control the laser power.

Back then I had custom Gcode substitutions in Prusaslicer which would replace Retract commands with enabling the laser and the opposite command with disabling the laser. It worked pretty well back then and I was able to do some engravings of circuit boards. I

There is one big safety issue, the enclosure is not designed for laser engraving and there is nothing preventing the laser from blinding you through a bad reflection. You will need to be extremely careful with this. The CNC machine I built later has a safety feature where the laser only functions if the front door is closed, using a magnetic sensor. It is not worth risking your eyesight over a bad moment where you don’t pay attention. Engraving lasers are dangerous. Also the fumes are nasty, especially when engraving plastics. The soot and tar it produces will also settle on the inside of your enclosure and also electronics that are in there. You need powerful ventilation to run a laser engraver long term.

As for engraving materials, I have two laser heads, a 0.5W 405nm laser and a 10W 450nm laser.

The 405nm laser can be used quite well to activate etch resist spray or foil and can also instantly and precisely cure UV resin. I could make legible text on a PCB using white resin, drawing the text and then washing off the excess with alcohol. This laser however is not powerful and you won´t get nice engravings on wood or metal with it.

The 450nm laser can easily cut wood and make very nice engravings in it as well. I have also used it in the PCB making process to burn away spraypaint so that the copper can be etched off.