MMU3 at CoreOneL will not work, always unloading the Filament
Good evening,
Today I tried to use the MMU3 on my CoreOneL. I used the official Instructions by Prusa and the same Buffer. The PTFE goes through the lid the same way like the regular one.
If I try to print something, as soon as the filament reaches the filament sensor of the Nextruder he tries to pull it back to the FINDA of the MMU3 imediatly. This is not possible because it has been pulled by the Extruder and create a faul message.... and the Filament is stuck.
I have absolutly no Idea how to solve this issue. The MMU was used on an MK4S without any problems.
What I tried and have done yet:
- Software MMU: 3.0.4
- Software CoreOneL: 6.5.3+12780
- conversion of printer according instructions by Prusa
- Nextruder conversion for MMU
- calibration of gearbox and filament sensor
- Printer is printing with deactivated MMU without any issues
- The PTFE from MMU to the Nextruder is 980 mm long, and I set the printer to a PTFE length of 980 mm
- The side filament sensor is switched on as prusa recommand
- Loading to MMU works
- For all testes, there is only one Filament loaded to the MMU, on position 1
- I tested all 3 filament sensors of the printer and all of them give a signal and the signal visible on the screen
- If I set the PTFE length to 700mm, the fast loating to the Nextruder stopps early an it loads slowly until the filament reaches the FSensor and the magic happens -> it tries to pull back to MMU ...
- If I set to 1000mm it will extrude some Filament and magic again -> ....
- Fastening the bolts on the swivel changes nothing untit it is too strong, in this case it get stuck -> magic is going to happen again...
- Losening the bolts on the swivel will end the Fsensor is not switching correct or too early / it is trapped in a loop of load und pulling back to FINDA
- The Loading Test function is ending in a loop of doom too
Does anyone has an Idea what could be the problem? That is driving me completely crazy.
RE: MMU3 at CoreOneL will not work, always unloading the Filament
Well I tried with the support about 1h everything.
Nothing worked, it get a level 3 topic. They gave it to the devs, lets wait what they figure out.
RE: MMU3 at CoreOneL will not work, always unloading the Filament
Same here with a Core One+ (upgraded from Mk4S)...
RE: MMU3 at CoreOneL will not work, always unloading the Filament
+1 for me with the MMU3 on Prusa Core One. I have the latest software for both the MMU3 and Core One. I flashed them multiple times, both for upgrade and for tech support.
The MMU3 reverses the filament as soon as it touches the Extruder. If I open the idler on the extruder the filament will feed close to a meter, but when the extruder is closed (like it should be). It just backs out. Even with the upgraded firmware it would print the first color but encountered this on the first change. And now this is all it does. I spent 4 hours with support a week ago. They said the MMU3 Specialists would email me, but it's been crickets and haven't heard a thing.
I'm going to pull the plug and revert to single filament and... box up the MMU3 (anyone want to try it?). I really like Prusa due to their open source ethics, but they are making is so hard to love them.
Subscribing to this. I would love to hear if there is movement.
RE: MMU3 at CoreOneL will not work, always unloading the Filament
I saw this type of issue occur this evening, no clicking. Looked like everthing was working properly, would unload the filament over and over again. Then I went to load a single filament through the side, the extruder started clicking. Thoughy it was a clogged nozzle, could not get any pla to move through it manual for a cold pull. Grabbed the CNC kitchen nozzle wires, ran them a few times, went in no problem, but still couldn't push any pla in for a cold pull, went back to the wires, then pop, while pushing the wires in, a broken piece of the Prusa Galaxy PLA popped out of the top of the nozzle tube. It was blocking the nozzle from receiving anything. The Galaxy PLA turns this into a jam o matic, it has major issues unloading from the extruder, had alot of failures where I had to remove the tube and pull it out manually, just needed more force, as the MMU would time out, was hoping I could limp the print through, never did finish the print. Matte PLA is also right out, failure -load to finda, the MMU grinds it down, too soft.
Core One L MMU3, MK3S
RE: MMU3 at CoreOneL will not work, always unloading the Filament
I have the exact same issue with a PTFE tube of about 900 mm (4 x 2.5 mm).
As soon as the filament reaches the extruder filament sensor, the printer tries to pull it back toward the MMU3 FINDA sensor. This is impossible at that point because the filament has already been grabbed by the extruder, so it triggers a fault message.
I was able to reduce the issue by lowering friction in the PTFE tube, even though it was already very low. I essentially used a more direct path of the same length.
While reducing friction seems to help, I do not believe it is the root cause. There is likely something else happening.