Laser Step Calibrations Issues - Different Across Bed!

So I’m running my step calibration process in order to get very precise measurements on some parts I’m working on. Got my 100x100mm squares, and multiplying my step length by the resulting ratios, etc. No issues there. However, I’m finding that I’m getting different measurements across my bed. So while I can get my calibration to produce a perfect 100mm square (+/- .02mm) near the home position, I’m getting a 100.5x100.7mm square near the center of the bed. I’m absolutely stuck on what to do next. These parts are done in batches from large sheets, so I would ideally have a tolerance within 0.1 mm across the bed.

Is there another calibration step I can take? Some sort of scaling ratio? Or do my motors just suck and I’m stuck with them?

Unit is a 100W HL-Yeah 1060L running a Ruida G644XG.

My assumption would be that this isn’t a stepper issue. Could be something physical like something out of square or an alignment issue.

Can i suggest you run a grid of the squares across the entire bed surface and get a map of dimension deviation for the whole laser? Based on the outcome could give you an idea of the scale of the problem and clues as to the source of the deviation.

Thats a good idea. It’s a step in the right direction, one might say! I’ll give that a try and follow up.