Thingiverse user peter_ recently posted an update for his ongoing project to design an inexpensive laser cutter using primarily 3D printable parts and extruded aluminum. This is one of several projects occurring right now to make laser cutters more widely available in a similar fashion as the Makerbot and RepRaps did for 3D printers.
It’s an ambitious undertaking, but it looks like he’s making good progress. The design appears to be mostly functional except for tweaking the laser alignment and adding a case.
The image below shows the enormous package that the CO2 laser tube came in. The glass tube is only about 2 inches in diameter, so that’s a lot of packing material.
The last image is one of the mirrors that deflect the beam of the laser from the laser tube to the work surface.