Filament deviates away from the pulley's channel as it enters the MMU, prevents automatic loading
I've had my perfectly-running MK4S for a few weeks, and now have applied the MMU3 add-on. I have found on first attempt at printing that it cannot auto-load filament. I am prompted to insert filament, I push it all the way up to the entry into the MMU3, and just after it enters the main body of the MMU3 it meets firm resistance. Nothing gets taken up, and the motor just keeps whirring until I stop the MMU3 with the middle button.
The idler is set at the specified tension (screws slightly protruding from flush), and the filament pulleys in the central cavity are perfectly lined up with the input and output holes. All input tubing is pushed up firmly to the end of the inspection slots.
If I manually cancel the load operation, and without pulling out the filament I open the idler and look into the central cavity, I can see the filament poking through into the cavity, but the entry hole into the cavity is so wide that it allows the filament to curve sideways away from the knurled depression in the filament pulleys. When I'm pushing the filament in, it's just mashing into the smooth part of the pulley, and there's nothing to guide it back straight.
If I instead manually guide the filaments over the pulleys and into the output holes so the filament is held in place above the pulley depressions, but not so far in that they jut out into the path of the selector, then screw the tensioner back to the specified position, it seems to work. I've printed the 5-colour test disc after manually guiding the filaments through, and it operated flawlessly. That being the case, having to open the MMU3 idler door and fiddle with the filament every time I want to load the thing is a bit much. Does anyone have any idea how to fix this?
Photo below of my MMU3 when filaments were manually guided in, after the successful print.
