Anal Thermometer Results - Where do I start?

[Doug Fisher]

I have spent quite a bit of time doing maintenance and functionality checks (belt tension, beam alignment, etc.). The beam alignment seemed to go pretty well for the first steps. I now get burns on top of each other in front of mirror three at all four corners. When I take the nozzle off and fire a test pulse at the correct nozzle height and then drop the bed three inches or so, the second test pulse is on top of the first one. After doing the five location anal thermometer test (Russ' term, not mine!), the beams are not centered as shown in the image below. I kept the orientation of the thermometer the same for all five. TL means the upper left corner of the bed (back near the tube), BR means the lower right corner closest to the controller panel, etc.

Anal Thermometer Laser Test 1a.JPG

Bottom left BL and top right TR are obviously off. BL looks a bit high and to the left. TR looks way off being low and to the right. Does anyone have quick rules of thumb for how I adjust the head mirror to correct this? I was about to just start messing with things and thought it might be more expedient to ask here first before I make things even worse. Here is a shot of my adjustment options for the head's mirror.

Laser Head Adjusters 1b.jpeg

Any helpful insights would be appreciated. Thanks!

[Pete Cyr]

Any helpful insights would be appreciated. Thanks!

viewtopic.php?f=105&t=3480

[Jeffrey Aley]

Is your gantry square? The simplest test is to cut a large rectangle of paper, and then fold it to see if the halves match.
Or you can just cut (mark) a really big rectangle on a piece of plywood and measure the diagonals or check with a framing square.

I think you want the gantry to be square first, before you start re-aligning. Otherwise, you'll just have to do the alignment all over again.

[Doug Fisher]

Thanks, Pete. Toward the end of that Thunder Laser they had some worthy notes on tuning that last mirror.

Jeffrey, I physically measured from the gantry to the rails using a carpenter's square and it appears to be square. I will resort to your method next if problems continue.

Thanks.