A simple method for aligning the laser beam in the Lasersaur.
This system can help you align your lasersaur safely. It uses a dismantled Quartet brand laser pointer found at OfficeDepot. We used a 1.25" dia wood ball with a 0.325" diameter hole drilled through it. We then pulled the diode out of its housing and placed it in the middle of the ball so that beginning of beam is at the rotation center of the ball.
The reason we made a ball and socket joint is that the diode of the 5mW laser is not centered to its housing. Once the alignment tool is on the end of the CO2 laser, you need to be able to rotate it so that it aligns with the center axis of the CO2 laser. You know you have the diode aligned when you rotate the entire fixture around the nozzle of the laser tube and the red 5mW beam stays in one place rather than tracing out a circle. You can then move your lasersaur mirrors to align the laser through the rest of the machine.
You will need to glue the top and bottom parts of the tool together. This was done to eliminate support structure so you had a clean bottom to sit on the metal nozzle of the laser. The screw eyelet is just there for a handle to rotate the ball.
Once you get the 5mW laser aligned, place a target over the second mirror, fire off the CO2 laser lightly (10%) to see where it hits. If it is off of the location you had with the 5mW laser. Don't panic. Just move the mirror mount of the first mirror (not the angle) to reset it in position. Fire it again, and then put the alignment tool back on. Get the 5mW laser beam to hit where the CO2 laser hit and then re-check/align the mirrors.
The reason you do this twice is:
The first time you align the mirrors is to get them normal to each other and the laser axis.
The second time is to account for any concentricity difference between the axis of the CO2 beam and the nozzle.
You should also use a piece of paper with an "X" on it and cover the lens tube to be sure that your 5mW beam is hitting center at all for corners and during the diagonal traverse.