Before starting a print the Lulzbot Mini goes through an auto bed leveling. On my printer the auto alignment seems to have gotten offset. It finds the front corner just fine but then stops on the bed before reaching the next corner and touches the head to the bed itself instead of the round metal corner. It used to perform this task no problem, is there a way to reset the auto-bed leveling?
I would suspect that the X stepper is missing steps or some other mechanical problem is preventing the X axis from moving the commanded amount. Belt tension, gear slipping on the stepper shaft, perhaps a motor or controller issue. Heatsink fell off the stepper controller maybe? There isn’t really a configurable amount it tries to move for the leveling, it’s hardcoded in the firmware. You can change it, but you have to recompile the firmware and reflash the controller. It’s not something that would happen by accident. It’s easy enough to rule out though, you can flash the latest from Cura. If that doesn’t help, and it probably won’t, you need to start investigating the other options. I may well have missed some, hopefully others chime in with other ideas.
That usually points to a bad motor shaft on the X axis.
Out of curiosity sheridanart, You mentioned it finds the front corner fine, is it having trouble with the 2nd washer? Are you able to gently push your X axis to where the nozzle should be roughly when the power is off to make sure your X-axis still moves fine?