Printer misaligned and x/y calibration off after printer was moved

I assembled the moai 130 and calibrated it on the bench top and it functioned as intended. I then I moved it and over the course of 10 days it seems the calibration of the x/y got worse and worse. I moved it again and retested the yuan test and cross-section test. Now the laser trace is extremely elliptical, as the extrema in the x are outside the build area and the y is slightly too large. The cross-section test is about 1 cm displaced in both x/y from the center. I am worried that the printer is beyond repair and I am trepidations about attempting the fix (

has anyone used this procedure to fix this kind of misalignment. Both moves were done gently with no dropping of the printer or banging the case into things. It was not stored in an area with excessive vibration. Any advice would be appreciated.

It looks like a bad contact on the galvo driver or cable.

Wiggle when the laser makes the circle, carefully on the plug connections and on the potentiometer (marked in red). If this changes the laser, you are close. Then check the connections / solder points or the contact resistances.


If that didn’t work, then swap the X and Y cables to the galvos and see if the error is now rotated by 90° (video).

Switching the x/y glavo data cables did not flip the ellispe.

Then I tap a broken galvo.

…If you are lucky, only one cable is loose on the galvo.

Just to make sure which X-Y cables you swapped.
The two to the galvos or the two to the mainboard?

A labmate and I followed the adv calibration guide i linked above and X/Y size was way out of wack but we managed to get it such that the laser was recentered and everything appears to ok. I am running a test print now.

The displacement of the laser is adjusted with the spindle potentiometer. It should have 10 turns. He cannot pretend by himself. A loose contact on the potentiometer can cause the above-mentioned error.

I wish you success!

We flipped the the x/y galvo data cables going into the galvo boards. This didn’t change the ellispe. We didn’t do anything with the mainboard.

Thanks, yeah it took a couple turns to start seeing the shape of the ellipse to start changing.