Why spend thousands on a laser cutter/engraver when you can spend as little as $350 shipped to your door? Sure it’s not as nice as those fancy domestic machines, but the plucky K40 is the little laser that can. Just head on down to Al’s Laser Emporium and pick one up. Yes, it sounds like a used car dealership ad, but how far is it from the truth? Read on to find out!

Laser cutting and engraving machines have been around for decades. Much like 3D printers, they were originally impossibly expensive for someone working at home. The closest you could get to a hobbyist laser was Epilog laser, which would still cost somewhere between $10,000 and $20,000 for a small laser system. A few companies made a go with the Epilog and did quite well – notably Adafruit used to offer laptop laser engraving services.

Over the last decade or so things have changed. China got involved, and suddenly there were cheap lasers on the market. Currently, there are several low-cost laser models available in various power levels. The most popular is the smallest – a 40-watt model, dubbed the K40. There are numerous manufacturers and there have been many versions over the years. They all look about the same though: A blue sheet metal box with the laser tube mounted along the back. The cutting compartment is on the left and the electronics are on the right. Earlier versions came with Moshidraw software and a parallel interface.

The K40 mechanics haven’t changed very much, but the electronics have been updated to USB with modern stepper drivers. Make no mistake, these are not “quality” machines. They are built down to a cost. Interlock switches are non-existent. Overheat protection for the tube is your problem. Low cooling water flow alarm? Nope, better keep an eye on that yourself. The cutting bed looks like a mixture of an afterthought and parts someone found in the spares bin. The exhaust duct is routed 3 inches into the cutting area. In other words, these are the perfect machines for a hacker.

I’ve been watching the K40 and similar machines on eBay for years. Originally these machines were shipped from China. It was a crapshoot if a large heavy gas filled glass tube would survive the trip halfway around the world. Now, many of the machines are shipping from California and other ports within the lower 48 states. I’m guessing the machines are shipped to a warehouse here in the USA, tested, then the good units are sent on to customers.

With all this in mind, I finally decided to jump in and get a K40 laser. My first problem was deciding which laser to buy. eBay and Alibaba are riddled with auctions from sellers with different versions of the K40. Everyone says they’re newer and better than the rest. Some boast …read more

Source:: Hackaday