Hello, One image worth thousand words. Those circles are 9mm in diameter. Start position is at (1), literally: machine is parked at (1) before starting. Laser starts at at (1) and then makes perfect circle finishing in (1). Then moves to next circle (2) and draws second circle (direction 3) which is not as perfect, and then moves to last one (4) and again circle is not perfect. Machine is controlled directly by Lightburn. Work speed: 300 mm/min Default max parameters for X and Y are 3000 mm/min and acceleration 250 mm/s. As Lightburn uses max machine speed for traversal moves, my first thought was that this is too fast. I slowed down to 500 / 50. Result is exactly identical. I tried playing with "Scanning Offset Adjust" in Lightburn and actually it did a pretty good job but on fill engraving, while it had no effect on those circles. I would appreciate any ideas what could be the reason and how to solve it.
you need to calibrate X (well, and Y and Z, but mainly X). leadscrews are never absolutely accurate so there is a calibration wizard in CONTROL under Wizards and tools. calibrate over the longest length you can measure properly.
Also double check shaft-coupler grub screws, and make sure all the Eccentrics are correctly adjusted.
SOLVED. So shaft-coupler grub screws were the solution. I was afraid to tighten them too much. Turns out they need some more... mans approach It solved the issue but anyway I checked calibration as well, using laser as very precise marking tool. X/Y on 1000mm travel were actually making 1002,3mm. Thanks for help.
