Filament won't reach inside the extruder
So after a recent topic where I was unable to load filament correctly, I was suggested to loosen the tension screws and I was successfully able to load filament. Later on though, I needed to perform individual filament calibration and so the filament attempted to travel from the MMU down to the extruder and I could see it inside the PTFE tube leading to the extruder, but it never made it down far enough. The filament must have been stuck between the top of the extruder and where it begins to be visible through the idler door as I could not see any filament inside the extruder whatsoever. I would try to push the left and right buttons on the MMU as instructed in the manual to have the filament reach the pulleys of the extruder but all that would happen was I would hear a clicking sound from the MMU and absolutely no change in the location of the filament in either direction. After ejecting the filament due to this failure, I noticed the filament was bent and chewed by the pulleys within the MMU
I have tried this again and again. I have even tried adjusting the tension screws to see if those may be at fault but to no avail. No matter what I do, I cannot get the filament down where it can be caught by the extruder's pulleys and the MMU buttons do nothing as all the MMU pulleys do is click and chew the filament. I've tried everything I could think of and could really use some advice.
Re: Filament won't reach inside the extruder
you may have to manually shape the entrance to the pulley under the sensor pcb. i had to file the area by hand to get rid of the layered steps as the tip would hit one jam and then the upper pulley would strip it out. and then the filament has no possible way to load itself as it was stripped and kept hitting the rough sides of the walls.
i used a round jewelers file with a tapered tip and carefully filed the area and retested with spare pieces of filament until i could no longer feel the tip catch anything. do not open up the diameter of the hole to the pulley just carefully smooth that entrance.
“One does not simply use a picture as signature on Prusa forumsâ€
Re: Filament won't reach inside the extruder
i think it's the hardest part of the build. getting the filament to move with as little restriction as possible.
cleaning up the printed parts help me the most. I did not have to take it too far apart. also loosing all the PTFE tubes helped.
don't forget every time you make the filament run different you might have to redo the calibration for it. I just went one at a time. as I was testing filament 1 and 2, I was cleaning up 3 4 and 5
I have a Prusa,therefore I research.
Re: Filament won't reach inside the extruder
you may have to manually shape the entrance to the pulley under the sensor pcb. i had to file the area by hand to get rid of the layered steps as the tip would hit one jam and then the upper pulley would strip it out. and then the filament has no possible way to load itself as it was stripped and kept hitting the rough sides of the walls.
i used a round jewelers file with a tapered tip and carefully filed the area and retested with spare pieces of filament until i could no longer feel the tip catch anything. do not open up the diameter of the hole to the pulley just carefully smooth that entrance.
So I just want to make sure I understand what exactly I should smooth out. What I gather from this is that the five small holes where the filament exits out of and then goes into the selector is what I need to ensure is clear?
Re: Filament won't reach inside the extruder
clean everything (not PTFE tubes)
ya those exit holes going thru the "mmu2 pulley body"
make sure the "mmu2-front-PTFE-holde"r isn't squishing the PTFE tubes.
and make sure the "mmu2-selector" is cleaned up. I even enlarged the input abit.
the filament should move real easy by hand. everywhere.
once that's done a calibration should be the last thing needed.
I have a Prusa,therefore I research.
Re: Filament won't reach inside the extruder
you may have to manually shape the entrance to the pulley under the sensor pcb. i had to file the area by hand to get rid of the layered steps as the tip would hit one jam and then the upper pulley would strip it out. and then the filament has no possible way to load itself as it was stripped and kept hitting the rough sides of the walls.
i used a round jewelers file with a tapered tip and carefully filed the area and retested with spare pieces of filament until i could no longer feel the tip catch anything. do not open up the diameter of the hole to the pulley just carefully smooth that entrance.
So I just want to make sure I understand what exactly I should smooth out. What I gather from this is that the five small holes where the filament exits out of and then goes into the selector is what I need to ensure is clear?
no the extruder body itself down next to the filament sensor pcb board. the filament exits the TPFE orange tube there is a gap, at the bottom is the entrance to the pulleys and down into the nozzle this area will need attention to get smooth loads.
“One does not simply use a picture as signature on Prusa forumsâ€
RE: Filament won't reach inside the extruder
I have the same issue! Did you solve it?