I wanted to use my CR-10 Mini 3D printer as a laser engraver.
I bought a 1.6W UV laser from China that I wanted a fast way to attach and detach from my printer. I opted to attach it with magnets and a custom bracket that fits the side of the hotend enclosure.
I cut the part cooling fan cable so that I could tap into it's 12v PWM signal. With an Arduino and a voltage divider I take that signal and create a 5v pwm signal for the printer. I also build an enclosed for the electronics and added some safety and convenience features such as key to turn on power, safety switch and latching power button (so the laser is always off when power is turned on). I also added a manual laser override so that I could enable the laser for zeroing in on the material and focusing.
This laser is a lot of fun! That said. Please don't do try this if you are not sure what you are doing. This is attempted on your own risk.
Print settings does not really matter for this model. It is really easy to print.