!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! WARNING !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Laser is very dangerous! NEVER use it without safety protection!! Even a cheap 250mW Laser can harm your eyes badly!!!

If you dont have any safetygoggles, use at least your phone´s camera (which is replaceable, not like your eyes...) for checking and focusing. But be also aware that this could damage the camerachip !!

I´m not responsible for any damage!
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Try to print one of the smaller parts to see if the inner diameters will fit to your printer. I made them 0.5mm bigger so they will fit to my Geeetech A30!
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I tried to build a cheap Laserengraver out of old DVD drives using parts here from Thingiverse. Since that didn't worked out like expected, i decided to design my own one, using parts that i had laying around. Please keep in mind, that a 250mW Laser just can engrave dark, natural materials like leather, cork, etc...

Long story short :-) Here are the Parts you will need:
1x 250mW Laser, Testetd and used in my Video (mounting for more powerfull laser comming soon)
https://s.click.aliexpress.com/e/_dVdFYFk
OR 1x 1000mW Laser (Not tested, can´t say anything about the relaiabilty of it )
https://s.click.aliexpress.com/e/_d8SLVCm
2x Timingbelt G2.5T (1m in total is more than enough) https://s.click.aliexpress.com/e/_dYMpcQ6
4x Bearings 625Z
https://s.click.aliexpress.com/e/_dVgLcWK
2x 28BYJ-48 12V Stepper motors (modifyied like in the description: )
https://s.click.aliexpress.com/e/_dWisYue
3x Screws M3x10
https://s.click.aliexpress.com/e/_dYCCKny
4x Smooted Rods (you can use every length, just 2 pairs per Axis)
https://s.click.aliexpress.com/e/_dZU3jhc
6x LM8UU Bearings
https://s.click.aliexpress.com/e/_Bf6YHSse
1x M8 Rod (length depending on the Rods youre using, You will need 2 for the Y-Axis)
https://s.click.aliexpress.com/e/_dT2z4Jy
1x M6 Rod (length depending on the Rods youre using. You will need 1 for the X-Axis)
https://s.click.aliexpress.com/e/_dT2z4Jy
4x Bolts M6
https://s.click.aliexpress.com/e/_d6H6OLc
8x Bolts M8
https://s.click.aliexpress.com/e/_d6H6OLc
Last but not least, any kind of GRBL Controller (Uno Shiel, old 3D Printer Hardware.... https://github.com/grbl/grbl )
https://s.click.aliexpress.com/e/_dTgSJxg

You have to modify the Stepper motors from Unipolar to Bipolar, that we can use them with normal stepper drivers. This is less work, than it sounds. Just open the blue Cover on the backside of the stepper, and scratch the trace on the PCB between the two conacts in the middle (on the red wire) and finally remove the red wire. Now you have a normal Bipolar stepper motor that you can use with every stepper driver

Set the Current of the stepper drivers to something around 0,09V or 0,08V to get a smooth working engraver without overheating. Dont tighten the Belts too much, otherwise the cheap gearbox inside will be damaged (i killed 5 motors with to tight belts, before i found out that this is a bigger problem)

The X-Axis can be tighten by the M6 rod in the middle ( i made the holes long enough)

As Software for engraving I´m using lasergrbl on a Virtual machine (linux user): http://lasergrbl.com/

Video of the working Laser in original Speed:

https://youtu.be/H9AmGd_vd2k