I am pretty confident that I am chasing a level of precision in cutting that might be well beyond what my new laser is capable of doing yet I continue to mess with it anyway! I have gotten pretty good at finding a focal point anyway.
First step is to do the eyeball (behind safety glasses!) calibration with the laser running at 1% of power as adjusted on the front panel of my printer. To aid this first focus I have found that using the camera on my smart phone helps as it has a macro focus that beats that of my eyes.
Once that is done I print the calibration lines seen below. Low power so that the paper is only just scored. The first test is done with 2mm build platform movements, then 1mm, then .5mm, and finally .25mm. Can do another one at .1mm but not shown here. Obviously the trick is to bracket each level from the previous test.
Having done the above, however, I am still not sure that I am getting the depth that I should be or not but more troubling is that I get two completely different depths of cut on the x-axis versus the y-axis! As you can see in the below photos the cut that I get on the x-axis, side to side, is dramatically better than the one on the y-axis, front to back? I am not seeing this when I print though I am going to further test this later today. I have done the things on the printer that I would do if I thought that I had an issue but will recheck those adjustments as well (tension on the small belts, equalizing tension on the long belts, ensuring all set screws on the pulleys are tight, lubricating the axis rods).