We all remember the diy cnc laser. In my quest to bring you guys fresh stuff, I found an interesting design [archived page](the author says he built his in the 80s) for a home-built CO2 laser. The dimensions are missing, but the design is pretty simple. If you like some textbook style reading, the hyperphysics server is your friend. I finally bought a mini mill to go with my lathe – this could make an interesting machining project. Get a mini-fridge compressor to for the vacuum source, and the gas is easily acquired from the local welding shop. I’d bet Surplus shed probably has some workable optics.
The 25th is the deadline for the Design Challenge. Don’t freak out, just get it submitted before I get up on the 26th, and I’ll call it good.