Laser cutters are a lot of fun. They’re also a lot of work. They’re also a lot of danger. But they’re also a lot of fun. So I decided to get one.
I’d used the laser cutters at the university many times. Those were large, powerful machines with motorized focus, powerful blowers and fume extractors, power tables, and much more. They could cut through pretty much anything organic in whatever shape you wanted with minimal time and effort, but they also came with a lot of rules to follow.
When you have your own laser cutter, all the rules go right out the window. Cut something with chlorine in it? Just hold your breath! Food? No problem, just clean out the residue with a little water! Flamables? Keep a bucket of water handy.
So I went out and bought a K-40 laser cutter from AliExpress. Its a sheet metal monstrosity with a tiny cutting area and no safety features. None – its quite possible to open the lid while the laser is firing, and stick your hand in the beam path. There’s a dedicated button on the control panel called “test” that will fire the laser whenever it is pressed, even if the tube is exposed.
Its selling point is the price (I paid $300 for mine) and the fact that it comes with a 40W CO2 laser tube. This gives it far more power than the cheap diode lasers sold as “laser etching” machines and allows it to cut through wood, cast acrylic, and many “big boy” materials.
K40 Laser Cutter. Note the lack of safety features.
I bought some laser safety goggles, a fire extinguisher, and set up fume extraction and a water cooling system for the laser tube. I set up the k40whisperer software on a computer and got to work. The first test cut was a butterfly on cardboard.
I built a manual focus axis out of scrap parts and a pizza screen mesh and then started etching some macarons. Here’s my first attempt at etching a laser safety symbol onto a cracked macaron.
Its not even close to perfect. The laser beam is obviously out of focus, and the speed is too slow allowing the center to burn. But its a start. I tried a few more times to tune the focus and the cutting parameters, and eventually got the process down to a science. Ultimately, this ended with me etching squirrels onto macarons for my PhD advisor’s birthday celebration.
I also eventually cut and bent some plastic sheets into masks around the start of the COVID-19 pandemic. You can see the fumes coming of the plastic in the video below – the lack of an air assist greatly reduced the quality of the cut. Because of the poor ventilation, I had to do most of the cutting in my backyard.
Overall, this was fun, but a lot more trouble and danger than its worth. Some materials smelled terrible when etched, and the fumes were probably toxic. The laser tube was a constant source of worry, and the machine was a fire hazard. I ended up getting rid of it after a few years.