Problem with firmware 1.1.9.16 and 1.1.9.28

We are a production shop, printing parts for carburetors. We have a gcode file on the SD card that is working for us (actually a lot of files). After the update to …16 and then …28 at Lulzbot’s recommendation a problem started after the first print of the day. The first print runs fine after starting the machine, when we try to print again it always fails at the ‘probing’. The print head is about 5 mm above the probing point and does not lower to the probe plate. Since the gcode ran successfully the first time we ruled out the gcode (and hasn’t changed in 3 months) . The problem started after the install of firmware …16 , we contacted Lulzbot and theyy told us execute a M119 from the terminal it Cura ( v3.3.32 ) but that is problematic since it is a probe / re-probe state and eventually fail and the printer does not respond.

Is anybody else have problems with this firmware?
Any help and recommendations would be greatly appreciated.

Thanks
Larry J
Daytona Parts Co.

What you are seeing is essentially bed compensation stack up. On successive prints, the bed leveling can add up causing this large gap. (See release notes here: https://code.alephobjects.com/w/cura-lulzbot/) We fixed this by changing the start gcode as described.

To fix this up, you can manually enter the gcode commands to your pre-existing file: M420 S0 before wiping/probing has been added, and M420 S1 after G29.

Alternatively, you can re-slice the file as the start gcode will be updated within 3.2.32 to match this issue.

Thank you for responding, Brent
We just roll the firmware back to 1.1.8.59 and every thing is working as expected. Your solution does make since so we will give it a try. It will take a while though since there are about 50 pre-sliced files that we are using and will take time to change. Looking at the latest version of Cura ( 3.3.32 I think) it does have those commands in the starting gcode so going forward we should not have a problem slicing new files.

Thanks

Larry