While some decent lasers are out there for under $400 USD, they tend to be a little small. What if you wanted something a little nicer but didn’t want to jump to the $2,000 category? The answer for [Owen Schafer] was to build it with parts he had lying around and a few strategic purchases.
While he was initially planning on using a diode laser, doing anything more than engraving is tricky. He purchased a cheap 40 W CO2 laser tube, but it meant that he needed water cooling, mirrors, and more complex stuff that a diode doesn’t need. The frame is aluminum extrusion held together with 3D printed plates. Given there was a powerful laser bouncing around with mirrors, a plywood box formed the enclosure.
The stepper controller is an Arduino Mega running the Marlaser firmware, though [Owen] admits perhaps a laser cutter-specific driver board would have been better as he spent many hours trying to get the Arduino to do what he wanted. Air ventilation is a tube with a fan that vents out a nearby window. Water cooling is just a bucket of water with a pump in it. A simple nylon hose connected to a compressor with a maximum airflow valve provides an air assist while cutting. Finally, we’re happy to report that [Owen] bought safety glasses specific to his laser to protect his eyes and researched how to ground the high voltages generated.
We particularly loved seeing all of [Owen’s] test cuts. He proudly displayed his boxes, sharks, and lamp shades like anyone with their new laser cutter is wont to do. If you’re looking to upgrade your laser, there’s an add-on for detecting materials optically or a relatively cheap laser bed you can throw in your laser.




[Sp4rky] got his laser diode modules out of surplus medical equipment and, unfortunately, the rated optical wattage was quite low. Since he had 3 diodes, he decided to try to combine the 3 low power beams into one high power beam. This can be done using a prism. A prism splits sunlight into a rainbow of colors because each wavelength(color) of light that passes through the prism is bent a different amount. Since the laser diodes only put out one wavelength of light, the beam bends but does not split or diffuse. A 3D printed bracket points each laser diode at a 3-sided pyramidal prism which sends the combined beam of light straight out the bottom towards the object to be cut or engraved.

