Bed leveling failure - Y-Axis issues?

I started a print normally yesterday and after about 3 layers the print started to misalign and it ended up like this before I stopped ot.

I didn’t think much of it and just gave up for the day, but when I went to start printing today my bed will now not level. The extruder won’t line up with the wiping pad quite right the first wipe and then it just goes downhill from there completely missing the corner sensor and the wiping pad before the leveling automatically fails. Video below

I don’t know quite what the issue is, but the Y-Axis doesn’t sound quite right, and I can’t put my finger on it. The tension on the belt seems fine, but when I try to manually move the bed using Cura or Octoprint it will not hit the end-stops, it just refuses to move further in that direction, it almost hits y_min, but is kind of far from y_max when it gives up moving that direction. M119 shows that the end stops are working if i turn the motors off and physically move the bed.

I’m totally at a loss as to what could be causing this, can anyone help?

Your y axis motor pull setscrews may have come loose causing the motor shaft to spin. Or it could be a cracked motor shaft, if it’s not the belt tension those are the usual suspects. If you are in warranty call support.

If you are out of warranty pull the y axis and take pictures of the bottom of it and post them here if it isn’t the pulley.

Ok, well I don’t have warranty so I went ahead and looked at the setscrews, I couldn’t really see them because they’re so far in there and there’s some kind of lubricant residue in there - I can’t even make out what kind of screwhead they are to try tightening them, but they looked pretty set in so I went ahead and removed the Y-Axis and then the motor and when I turned it upside down to take a better look at the screws, this happened…

I’m not an expert, but I’m pretty sure that’s not supposed to happen…

Yup, broken Y motor shaft. You need a new motor. Possibly a new pulley too if you can’t get that one loose. I’d call support anyways on that one even if you are out of warranty. Whats interesting there is thats also probably not a taz 6 motor. The 6 uses Moons motors with the removable connector plugs. Thats one of the 5 style motors and possibly part of the small batch of failure prone motors they had.

the good news is that motors are a relatively inexpensive fix, you’re looking at $22 for the motor and $7 for the pulley assuming you can’t remove the existing one

yeah, already ordered the parts. Thanks for your help!