This is GRBL-related. I have a laser-engraver type machine, Chinese, ~550 mm X axis, aluminium extrusions, 2mm-pitch T belt, Nema 17H3430 motors, one mechanical homing switch for X, Arduino-based.
The X-axis accuracy is not up to par. When I make a mark on the X axis and jog to that mark (after homing), depending on the day, the position varies within ~4 mm or so. Sometimes I have to use G00 X-418, others G00 X-422.
I checked the belt tension, it seems OK, not too tight, not too loose. Is there something else I should check?
Another idea I have: put a homing switch on the other end of the X-axis, then home both ends of the X-axis, measuring the difference in machine position, then modify the steps/mm value for each session to force the command that puts me on the mark to be constant (e.g. G00 X-420). Any other ideas? Thanks.