This is take 2 of a laser alignment tool. This tool, as the last one, mounts to the front of the nozzle of the Lasersaur laser tube. It uses a simple Quartet brand laser pointer from Petco and some cut to size mirrored plastic from AutoZone. you get something like a 10"x10" sheet for $9. You will need to cut the mirror and double side tape it in place.
You may have to use a little masking tape to shim up the fingers and get the device to stay in place on the nozzle due to print and nozzle tolerances. Once you have the fit correct, simply slide the laser pointer into the barrel until the button stays depressed. Place the device onto the laser nozzle and with the laser light on, simply rotate the tool to make sure that the beam line (it is a line not a point) rotates around its center and doesn't trace out a circle. If it does trace out a circle, you can use another piece of double side tape on one end of the mirror to shim it and pint the laser parallel to the tube axis. Keep shimming until the device stops tracing out a circle and the laser line spins in place.
From there you can simply align each of the Lasersaur's mirrors. This will get you "most" of the way and will make laser alignment a little easier. I say most of the way, because there is an assumption that the CO2 laser beam is coaxial to the center axis of the nozzle, which is probably not exactly true. Also due to the linearity of the laser pointer there is some error in finding it's center as well. BUT this will get you most of the way there.
I have done some research and due to the way these low cost diodes are manufactured, the process will always give you a laser line vs a single point. If you want a single point you need a tube style laser or pay a large amount for a more precise diode. I figure...it's close enough for what we are trying to accomplish.