Auto-Leveling sequence getting skipped at random.

On the newest version of Cura LE and Firmware, randomly just completely skips the bed probe/auto-leveling sequence.
It will home, heat to wiping temp, wipe, parks the printhead over the back washer like it’s going to begin the sequence, pauses, then just moves directly into printing once printing temp is reached. Starts printing about 2mm up from the bed when it does this

It does it maybe 1 out of 5 or 6 prints perhaps. I have not managed to get it on video yet, figured I would come looking to see if anyone else has an answer before setting up the tripod to film repeated starts and aborts until I get a couple good examples captured.

Hi B4DWolf,

you are not alone - I have observed skipped auto-levels 2-3 times after in upgraded my firmware along with the installation of an Aerostruder. Like G29 was simply not there in the gcode, but it was. This has never happened during the first print after powering up the Mini, only when I made more than one print.

I do all my slicing with Slic3r, only the start- and end-gcode sections are copied from Cura (suitably edited). This seems to suggest that there may be a bug in the firmware.

My firmware:
Send: N1 M115*39
Recv: FIRMWARE_NAME:Marlin FIRMWARE_VERSION:1.1.5.71 EXTRUDER_TYPE:Aerostruder SOURCE_CODE_URL:https://code.alephobjects.com/diffusion/MARLIN PROTOCOL_VERSION:1.0 MACHINE_TYPE:LulzBot Mini EXTRUDER_COUNT:1 UUID:351487b6-ca9a-4c1a-8765-d668b1da6585

I have the same Firmware
[16:47:17] FIRMWARE_NAME:Marlin FIRMWARE_VERSION:1.1.5.71 EXTRUDER_TYPE:Aerostruder SOURCE_CODE_URL:https://code.alephobjects.com/diffusion/MARLIN PROTOCOL_VERSION:1.0 MACHINE_TYPE:LulzBot Mini EXTRUDER_COUNT:1 UUID:351487b6-ca9a-4c1a-8765-d668b1da6585

Though, if it never happened on the first print, and easy work around is just to power cycle the printer.
Making it hard to justify wanting the LCD controller though, with it being flaky.

One thing we would like to double check is that after updating to the newest Cura, you added a new machine? The firmware changes in the 1.1.5.71 branch will require new start gcode in order to probe and wipe properly. If you have not added a new machine (and preferably cleared your cache,) you will still be using the old start gcode which can cause some confusion.

Let us know how it goes!

That had already been done, cache cleared and all that.
I haven’t had it skip in the last ehh dozen or so print starts.
But now, it has been exhibiting an odd behavior, the rear right (as looking at it from the front) corner in the auto leveling sequence, it will fail probe and rewipe often multiple times.
Nozzle is clean, washers are clean, I even unscrewed that one and blew out the hole and made sure all of it was clean, screw, flat washer, and standoff. It’s like that corner has a weak electrical connection, the other 3 don’t seem to exhibit any issues

This sounds like your x-axis might not being sitting level try checking it using these steps: https://ohai.lulzbot.com/project/leveling-x-axis/maintenance-repairs/

This sounds like your x-axis might not being sitting level try checking it using these steps: > https://ohai.lulzbot.com/project/leveli > … e-repairs/

What’s the process on a Mini, without an LCD display?

I believe step 6 is the only step in that procedure that uses the LCD display. You can use the control interface in CuraLE to accomplish the same thing.

My Mini is doing the same thing every now and then. Also have the newest version of Cura as well as Firmware.

G29 sometimes failing to do any probing was (is) a confirmed problem in 1.1.5.xx firmware. See this discussion for more info:
https://code.alephobjects.com/T1775

Has not happened to me since moving to the 1.1.8.xx firmware branch (but I believe 1.1.8.xx is still considered “development”, not production, so use at own risk or wait for production release).

I can confirm that a firmware update indeed appears to solve the problem of the skipped auto-leveling. Now I am finally happy with my recent Aerostruder upgrade - what a ride !