Paremetric lasercutter mirror alignment aperture

Many labmanagers running a lab perform this every once in a while: Cleaning and adjusting the mirrors of a CO2 lasercutter.

I would usually do this with painters tape and check that firing the laser from all corners of the bed would burn the same point on the tape. The downside of this is that it can be hard to place the tape on exactly the same spot, making it hard to judge if that point really is the same. I designed this little aperture that you can put the tape on instead to keep better track of the progress. I recommend keeping the hole of the aperture as large as possible when adjusting lasercutters, since the tape often ignites and plastic will likely also be a (more poisoinous) fire hazard. I do have used this same aperture generator at work too for apertures with smaller holes though, for aligning visible lasers such as interferometer systems used in elektron microscopes.

This model uses OpenSCAD, which is free and open source software (FOSS) that I think every programmer should use at least once :-) The cylinder that goes into the opening also has a slight chamfer of 5%, to make it easier to install and allow a snug fit to keep it from falling out.