Mini 2 kills when calibrating before a print

I have a Mini 2 that kills when calibrating during bed leveling. I never really noticed it until I was forced to revert to Cura because Cura LE is no longer supported for me. It happens when the head is calibrating against one of the corner pads - it may happen on the first, second, or less often, the third pad.

I’ve contacted Lulzbot support and they can’t help because I’m not using Cura LE. Are Lulzbot printers really only meant to work with Cura LE and nothing else?

In any case, I’ve noticed if I preheat the extruder, it helps get past this issue (sometimes), but I’m wondering if it’s just a script or something that I can run in Cura which Cura LE does automatically?

Also on a seemingly related note, it often won’t lay down PLA when I go through these kills (I usually have to reset two or three times). When that happens, I need to do a filament change, then it usually works. For a while.

I assume you are running Cura on something other than Windows, correct? Lulzbot printers are not CuraLE only, but CuraLE has some features that are not easy to duplicate with other slicers.

In any case, your problem appears to be a dirty nozzle and/or dirty corner washers. The corner washers can be cleaned with Isopropyl Alcohol, a Scotchbrite pad, and/or very fine grit sandpaper or pad (1600 grit or higher). The nozzle should be heated to the temperature used for the filament and then carefully cleaned with a non-conducting tool like the above Scotchbrite pad. If you want to use a conducting tool like a brass brush, then heat the nozzle, turn the printer off, and then clean the nozzle. If the conducting tool shorts out the heater or thermistor wires while power is applied, you can damage the controller board.

The leveling sequence (G29) should be run with the nozzle heated to around 140 degrees. One of the things CuraLE provides is the start (and end) gcode sequence(s). Also the ability to update the firmware (there are other ways but nowhere near as simple as using CuraLE).

On my LulzBot TAZ 6, I use Ultimaker Cura, Simplify 3D, Prusaslicer, and other slicers but I copied the start and end gcode sequences from CuraLE. There should be a series of wiping commands in the start gcode as well.

Another useful item to use is cleaning filament, eSun is one brand but there are others. This can be used to clean any filament stuck in the path by doing cold pulls. You can cold pull regular filament, but the cleaning filament just does a better job, IMO.