Hi guys!

I finished my 900x900mm MPCNC machine and after solving my inicial problems with the right belt tightness and the z rod lubrification, it started printing like a charm.

But now there’s this last detail that I haven’t yet solved which is the calibration of the XY axis.

Geometrically it’s printing perfecly, making perfect squares having diametrical measures exactly the same, but the sides are having a systematic error, where when I make a 50x50mm square, it really makes a 47x47mm square.

I’ve printed and bought all parts exactly as the original specs, 16 teeth pulleys, belts, bolts and nuts, everything so I’m surprised with this 3mm error. I guess that this will be solved by changing the original parameters for X and Y at DEFAULT_AXIS_STEPS_PER_UNIT, but first I’ve got to find out what might be doing wrong.

I hope you guys can help.