I’ve not been able to find anyone else with a similar issue, but to summarize, I’m getting intermittent filament change errors.
The printer throws an error about not being able to retract filament, but I caught the error happening on camera, and it only happens when it fails to load new filament, but it gets stuck and can’t pull it out to try again. It never fails to unload filament when it’s done with the current color.
In the video the print job is running some custom G-Code for filament changes that pulls back a bit of filament before cutting, but even using stock profiles for 0.4mm and stock filament profiles the error still occurs.
If I had to guess, the extruder gears are grabbing on to the filament when it thinks its failed to load, but refuses to spin them back until I press retry?
I’ve not had this kind of failure until the most recent firmware but I also haven’t done much multicolor printing until after the update too.
This happens across two different AMS units as well, failing to load from pretty much any slot, various filament types as well. This print job only used Bambu filament too. PLA Basic, silk, and marble all do it, along with Support W.
Edit: I’ve also fully disassembled and cleaned out the extruder assembly, even going as far as to remove it during one of these retraction failures and filament pulls out just fine once its not bound by the locked extruder motor.
Edit 2: Downgrading from 1.05.01 to 1.04.02 seems to resolve the issue. So this may just be a bug in the firmware with how it handles failed filament loads?