IT ISN'T A TOY, YOU ARE USING IT AT YOUR OWN RISK!

Laser engraver for Chinese laser pointer called "Laser 303".
It's designed to push laser pointer button on, so you are turning laser on and off with key that is part of laser pointer! It's pretty rigid and easy to install.

Materials i tested and speeds i recommend for engraving:

How to use:

1. Educate yourself about safety protocols around laser light.
2. Demount hotend and hotend cover.
3. Install on metal plate that is directly part of x-axis gantry crane.
4. Set Z axis home (i reccomend doing it manually by pushing z stop button) at the material you want to engrave as when holder is almost touching surface it blocks laser light pretty well so it won't reflect directly to your face or surroundings.
5. Use key that is provided with “Laser 303” to turn on laser pointer when Ender 3 is starting it's path. Remember that if your home is set manually ender can sometimes push holder into printing plate so it make brake and shine right at your face, test gcode without laser turned on before engraving!
6. When Ender is ending it's gcode then turn off laser! You have to be nearby to do it.
7. Don't forget to like this model if you like it and send some photos in comment section!
8. Enjoy your 8 USD engraver.
   

How to build:

1. Buy “Laser 303” or “Laser 301”, i have tested it only with “Laser 303” but Laser 301 also might be working with this mount as their sizes are pretty similar. Here how it looks, it's pretty hard to find on Aliexpress because from what I am seeing, they banned sales of powerful laser pointers at this platform. But if you search for it for 10 minutes guess you can find few sellers with this product. You can find many sellers of those lasers on ebay, amazon etc. This Laser is offten shipped without 18650 cell and charger for it, you need to have one to run this laser. Also note that 18650 cells that are in kits with this laser are almost always really bad quality so i recommend buying branded cells for this project.
   
2. Print holder. It's pretty easy to print, needs little support and generally prints well. I used 35% infill but for better stiffness you might consider going to infill 80% or even higher.
3. Demount hotend and hotend cover.
4. Use screws from hotend and hotend cover to screw holder into place. That's all!
5. If you picked version with BLTouch mount then also screw it to holder.
   

*DO NOT USE GLASS TABLE AS IT MIGHT REFLECT LASER LIGHT !
*DO NOT USE WITH REFLECTIVE SURFACES SUCH AS GLOSSY PLASTIC!
*DO NOT LEAVE YOUR PRINTER WITHOUT SUPERVISION WHEN IT'S ENGRAVING! IT IS FIRE HAZARD!
*USE LASER PROTECTION SUCH AS LASER BLOCKING GLASSES!

REMEMBER YOU ARE USING IT AT YOUR OWN RISK! LASERS WITH THIS MUCH POWER ARE ALWAYS DANGEROUS! IT'S OVER 100 mW OF OUTPUT POWER!