lps-rocks
commented
2 years ago I found that this was due to my warm-up and loading temperature being 160C instead of at least the minimum defined of 175C - The documentation states the hot-end doesn't have to be hot in order to load a 'Tx' command but if it's not at the minimum the E-axis motor will not advance and help during a load, so it's not exactly the same - I'll report this upstream.
Please, before you create a new bug report, please make sure you searched in open and closed issues and couldn't find anything that matches.
Printer type - MK3s+ Printer firmware version- 3.10.1
MMU Upgrade - MMU2S **MMU upgrade firmware version 1.0.6
Describe the bug First, it's important to understand that during a 'Tx' load gcode command, the extruder does not activate or turn the E-axis stepper during the loading process like it does during a 'T' or a 'T?'. This is okay for a stock Prusa extruder since the MMU2s has enough torque to overcome the resistance of the direct-drive of the E-axis stepper on the stock Prusa extruder and is able to force the filament down between the gears on the E-axis. However, when loading with the Bondtech extruder or any geared extruder the MMU2s does not have enough torque to overcome the resistance. Therefore, the Bondtech firmware should be modified to slowly advance the E-axis during filament loading of a 'Tx' command and stop the E-axis once the IR filament sensor has been activated (this signifies the filament is loaded to the gears).
To Reproduce Set up a print using the 'Original Prusa i3 MK3S + MK3S MMU2S Single' Printer profile in PrusaSlicer on a printer with a BondTech extruder body - The MMU has a high failure rate of successfully loading using a 'Tx' command since forcing the filament into the gears takes a significant amount of torque.
Expected behavior The E-axis motor should advance slowly in order to aid in loading the filament to the gears and then stop.
G-code N/A
Video N/A