Reverse alignment tool for K40 laser cutter

This is a simple reverse alignment tool that holds a 12mm diameter red laser module (the kind with a lens) on the laser head of a K40 laser cutter. To use it, you remove the lens and its holder from the laser head and push it onto the remainder of the head. The laser module is powered by 3 AA batteries in a battery holder. If you have access to a lathe, the function can be improved by making a12mm diameter ~5mm thick Delrin insert to go above the laser and using the tailstock of the lathe to drill a 1.5mm hole through the insert. The insert can then be press fitted into the 3d printed part above where the laser module will sit. However, the tool will function without the insert. Reverse alignment will not mean your K40 is perfectly aligned. This is because the red laser light may not exit mirror #1 at the same angle that the IR light from the CO2 laser tube enters it. However, it should not be far out and using the 'burn the tape technique' should quickly bring the K40 into alignment.