This is a small block that fits between the laser and the original x axis carriage for a Prusa I3. You can get the x carriage stl from the Prusa website

Now added modified version that will mount to Toms Dolly x carriage with circuit board end stops

The laser is this one

https://www.banggood.com/445nm-2_5W-2500mW-Blue-Laser-Module-With-Heatsink-For-DIY-Laser-Cutter-Engraver-p-993521.html?rmmds=myorder&cur_warehouse=CN

To fit it, you need to put the hex nuts into the capture holes first. Secure the laser to the block then screw the whole thing to the x carriage

You will need 4 M3x10 bolts for the laser and 2 M3x18 to bolt the completed assembly to the x carriage

I can't tell you how this handles on the machine as I am still in the process of building an I3 clone laser engraver

Prusa

i3 MK2 MMU

No

No

.2mm

25%