Probe Failure with Mini 2

All of a sudden, my Mini 2 is sticking me with a probing failure every time I try to print. It seems like it might be an issue of the X axis not being level (see photo), but I cannot adjust it through automatic leveling procedures available via the LCD. I am at my wit’s end with this. I have scoured the Internet far and wide and tried many suggested solutions including but not limited to cleaning the washers and nozzle, replacing the wiper pad, taking apart the tool head to make sure nothing is stuck, etc. I even took the cover off the control box to check wiring and nothing looked off, but I’m not an electrical engineer.
I am attaching photos showing the errors I get on the LCD and on Cura as well as the video of what happens when I try to start a print. Can anybody help, please?


Cura Error (sorry for screen photo):

LCD Error:

Video: Lulzbot Mini 2 Probe/Bed Leveling Error - YouTube

On my Mini 2 at work, I have put G34 after the G28 homing and before the wipe command in the startup GCODE. It counters the sagging of the right side that happens when the steppers aren’t powered.

But the video looks like you’ve got a massive Z offset being set somewhere.

What is the z offset set on the machine?
Is there one set in your slicer?
What does M503 report when sent via the console? M206 can screw up offsets too.

Thank you so much for your help and clarifying questions. I did notice that the z offset looked worse than usual, but wasn’t sure how that could suddenly be so. I’ll do my best to clarify:

What I get when I send M206:
What I get when I send M503:

There’s a lot going on here and I’m not sure what to look for exactly.

The Z offset was set to -1.20. I changed it to -1.10 but can’t tell if anything really changed.

I’m not sure how to tell if there is one west in my slicer; I tried searching “offset” in CuraLE but couldn’t find an option for it.

I’ll try adding G34 to the startup GCODE in the future. Thanks for the tip.

Everything in there seems to be in order.

I watched the video a bit closer, and at 12s in, it’s obvious your gantry is not moving in sync. The right side lifts significantly before the left side starts lifting. It seems to stay out of alignment when it lifts to the top as well. With the gantry that out of alignment, it could be jamming or at least slowing things down enough that it’s not going all the way down.

When it does the mechanical alignment at the bottom, the left side looks like it’s stopping too soon.

Thank you so much for your help.

I’ve observed what you’ve identified, but I’m not sure whether this is something I can fix myself or would need to send it in for. I’ve done mechanical fixes for this machine and my Workhorse before, but those were mostly involving the tool head; nothing like the gantry. Any advice on how to fix this or keep this from happening in the future?

You might take a look at the OHAI for the Mini 2.

A loose belt, or maybe the z brake board are the only likely things I can think would cause the problem. Maybe an out of square frame, to but that’s very unlikely with a mini. Also check for loose screws that would allow enough play in the frame to let it sag.

I have, and I appreciate the link, but I can’t find any guides that mention the gantry except instructions for the TAZ. I’ll look around the pages for the mini, though.

I’ve checked for loose screws but will check again. I’m going to see if I can realign the gantry manually as described here:
I’m not sure what I’d do to fix a loose belt or z brake board, though. I’ll keep researching. Thank you for your help!

One problem I see is that the Igus bearing on the right rear Z axis rod is out the bottom of the right X end piece a bit. It needs to be pushed back up to the top. Then there are two screws you can tighten a bit to clamp it better.

Check the Z belt tensions - since you don’t have a tool for this, I’d just say push on them sideways and feel the tension, and if they feel similar one has probably not slipped and they are OK.

You want to get rid of how the right side goes up before the left after it hits the bottom. Look for anything that is obstructing the movement on the left side. One thing that sometimes causes this is the cable chain hitting the wires at the bottom or the plastic guard piece around the hole where the wires come out at the bottom left. Another thing is having the two screws that clamp the left side bearing too tight, so there is too much drag on the left side.

The Z brake board isn’t the problem. If it wasn’t working you would have much worse movement issues.

I don’t know if the G34 even works on the Mini 2. Try homing the printer with the GLCD menu, then run the “Auto Z-Align” or “Level X-axis” from the move menu. Those are the same leveling function, just named differently depending on what firmware you have. Then start your print.