Tech stuff first then my question…
I did the camera upgrade to my yorahome 15w fixed focus diode laser.
Did the lightburn “calibrate camera lens” and “calibrate camera alignment” and got scores 0.13 to 0.16 using the circle card , did all positions , did not skip any. Laser engraved the alignment 1,2,3, and 4 circles and centered the crosshairs on each one of them.
I then tested the laser travel to a visible point in the snapshot taken by the camera and had to adjust the x-shift to -5.5 and the y shift to -24.5 and that put me bang on. I probably spent 5-6 hours playing with this new way to send the laser exactly where I wanted it to burn and was extremely pleased because using the camera is a “gamechanger” as far as positioning items on the bed to be burned. Extremely happy !!! Accuracy was to 1/32nd of an inch or maybe even better !!
OK here’s my question… today I started playing with the camera/laser positioning again expecting the same results that I had yesterday and LO AND BEHOLD the “burn” was about 1/2 inch higher and 1/4 inch to the right of where it should have been. Checked that the x-shift was still -5.5 and the y-shift was still -24.5 and yes they were. Changed the x-shift to -10 and the y-shift to -35 and it is “bang on” again. have done 6 tests since and the “burn” is perfect every time.
Why did this happen and do I have to do a realignment adjustment to the x-shift and y-shift every time I start a new session???