Mini 2: uneven X rails, Y position off

I just replaced the toolhead with the 1.75mm one. After I was done I noticed that the left side of the X rail was lower than the right. I must have pushed down on it when I was working on it or something like that. I figured it would even itself out, so I turned the printer on. I head a bit of grinding when it hits top (or bottom, I don’t remember now), but since then the left side remains lower than the right. Even when I push it with my hands to be level, it goes back to the uneven state.

Also, when the printer starts to print, it wipes the extruder against the bed itself, not the felt pad, as if the bed (the Y position) was off.

What should I do next? How to fix this?

Perhaps someone will be able to help you that is more specific to your machine, i only have experience with the Taz6 but… This happened to me, mine has screws though and i believe yours is belt drive? My buddy spun my linear screw on accident so i had to use calipers from the X rails to the bed on each side to rotate it back. Is there a way to skip the belt on the pulley so you can lower one side of it to match the measurement on the other?

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I ended up doing something similar: I held the X rails in place at a level position and turned each rod in place with a pair of pliers (through a rag to avoid scratches). That got them to re-seat and now they stay level.

Regarding the Y position—I’m not sure what happened, but it fixed itself. I left the printer turned off for a while and when I turned it back on, it was back to normal.

The mini 2 should have an X axis leveling routine accessible from the lcd menu. This automatically levels the x axis, which is prone to becoming tilted out of alignment on some machines.

I have a Lulzbot Mini One, I have had the problem of uneven y axis because of connection issues with Octoprint. It once decided that when it disconnected to ram the extruder into the build plate and make a crater in it. There was a grinding noise similar to what you described as the servos tried to push the extruder through the bed. The X-axis was then uneven. To fix this you need to bring the extruder close to the build plate corners and while holding one of the Y-axis screws in place, turn the other one until it just barely touches the metal contact pads on either corner(use a piece of paper underneath the nozzle for optimal contact). Repeat this with the other side now holding the opposite Y-axis screw. This should level the X-axis. This might also fix the grinding because it sounds like the limit switches are not making contact with the rail.

Mini’s have screws on Y axis and belt on X axis.

Also, clarify exactly what happens when your printer wipes the nozzle, does it clip the top of the felt pad plastic holder thing? or does it literally wipe it on the build plate.

The X axis leveling didn’t help because there was some tension forcing the misalignment. I could push the ends of it by hand into alignment, but when I released them, they settled back into misalignment.

It did literally drag the nozzle on the build plate.

If you have an original mini (with lead screws) and it is “settling back into misalignment” that does not sound right. Leadscrews take quite a bit of axial force to turn.

But note that you should not be leveling your x carriage to the bed, because your bed is not guaranteed to be square to the frame. Your leadscrews OTOH are mounted square to the frame (unless something has cracked or broken on your leadscrew mounds which you should check). So the X carriage should be squared to the underside of the leadscrew mounts at the top. Alternately you can measure up from the mounts at the base. Just don’t use the bed.

On my new to me original mini, I jogged the Z down to almost the bottom then used calipers with the power turned off and tried to get both sides to be 2mm from the lower bearing by rotating the motor coupler by hand. Once they were extremely close to the same distance it made a big difference. I noticed when printing now that just moving in the x and y the z motor couplers barely moved (showing it was pretty level as the autoleveling was not needing to adjust Z much).
I also noticed with the power off the y motion was not smooth across the whole distance (binding near ends). I took the heated bed and glass off, then loosened the screws that hold the rod bearings and pushed the bed to the end with the most binding. Then I tightened them in that position. The motion was much smoother now across the whole y motion. My guess is someone tightened the screws with it in the middle.

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