Filament not being pulled out enough by MMU2s - getting stuck in selector
Hi all,
My MMU2s isn't pulling enough of the filament out (retracting it?). It always now leaves about 1cm sticking out, and when the selector moves, it pushes the filaments over, bending them... completely screwing everything up.
All the hardware, tube lengths are stock. The one difference is that I'm using Autorewinders rather than the standard Prusa rollers w/ buffer (my MMU2s package had the mounting parts missing! so I settled on Autorewinders).
Please help!
RE: Filament not being pulled out enough by MMU2s - getting stuck in selector
OK. I've tried the "Individual filament calibration", testing now.
https://manual.prusa3d.com/Guide/Service+menu+-+Individual+Filament+Calibration/842
RE: Filament not being pulled out enough by MMU2s - getting stuck in selector
still no good... i'm starting to pull my hair out.
RE: Filament not being pulled out enough by MMU2s - getting stuck in selector
something must be slowing down the filament. OR finda is in a funk.
ive had to replace the ptfe tubes for such issues if I remember correctly. or maybe the "top cap" for the 5 filaments is too tight.
go slow. print single filament prints let it finish and see if its out all the way.
I have a Prusa,therefore I research.
RE: Filament not being pulled out enough by MMU2s - getting stuck in selector
something must be slowing down the filament. OR finda is in a funk.
This is my thought as well. In my efforts I found that the MMU seems to be really finicky about drag on the filament.
Switching to the auto-rewind spools helped greatly over the stock trays. Initially I started out using the long PTFE tubes meant to go from the buffer to the MMU, but I dropped back to installing the short PTFE tubes in the back of the MMU and that seemed to be the last turn on my path to 5 color printing.
I will try the longer PTFE tubes again in the future when I get a more permanent placement solution for the spool holders. I think the issue is simply that they are too long for how close the holders are to the printer and this caused them to have some tight bends that added just enough drag to be an issue.
RE: Filament not being pulled out enough by MMU2s - getting stuck in selector
Thanks guys, I'm still struggling, but I'm already using Auto rewind spools. I am still using the original Prusa tubes though, which are quite long, and my spools are quite close to the printer. Maybe I should investigate this.
I have another issue now with the printer helpfully unloading filament shortly after it's loaded and printed a few lines in the wipe tower.. telling me that my filament has run out. Even though the IR sensor info displays "1" the whole time.. but I'll leave that for another topic.
This is really testing my patience.
Thanks for your help though, it is very much appreciated.
RE: Filament not being pulled out enough by MMU2s - getting stuck in selector
Thanks guys, I'm still struggling, but I'm already using Auto rewind spools. I am still using the original Prusa tubes though, which are quite long, and my spools are quite close to the printer. Maybe I should investigate this.
Yeah just swap the long tubes for the short ones and give that a shot. My spools are only 6" from the rear of my printer so the long tubes twisted all over the place. I suspect that when I determine my final setup that I'll be able to properly size tubes that will work to contain the filament from end to end.
I have another issue now with the printer helpfully unloading filament shortly after it's loaded and printed a few lines in the wipe tower.. telling me that my filament has run out. Even though the IR sensor info displays "1" the whole time.. but I'll leave that for another topic.
What about the FINDA reading? After ejecting the filament do you see any ground down areas? It could be that the MMU idler is grinding a divot just deep enough for the FINDA ball to fall and trip that sensor.
Given how many people have had issues, however, I suspect the IR sensor and how it interacts with the idler door. It seems to be common that everything looks good when you set it up, but then once the printer starts moving you get these false events. The simplest way to test this is to disconnect the MMU and see if you can get through a plain MK3S print with the IR sensor enabled. I couldn't get through a 20x20x20mm cube without multiple run out events. After replacing my idler door and getting the arm dialed in I could then print the cube with the sensor enabled and have not had any more issues.