Newbie Questions on MMU3
Hi,
I haven't used an MMU but have been using Prusa printers for several years. My question is can the MMU be disconnected quickly to allow a MK4/S to print standalone?
I quite often use flexible, foaming PLA and a few other different filaments that probably wouldn't be MMU compatible. It looks as though you could just unscrew the tube from the nextruder and screw in another from a single reel, but is it that simple?
Regards,
Paul
RE: Newbie Questions on MMU3
Hi Paul,
I believe your question is answered in the manual: No, it is not possible to quickly disconnect it since the Nextruder will need to be modified.
https://www.prusa3d.com/downloads/manual/prusa3d_manual_mmu3_en_102.pdf
(Chapter 8.1. Mounting/Unmounting the MMU3 unit)
That was for me one of the reasons to not immediately decide for the MMU3 because I don't like these teflon tubes/hoses in the filamenmt path but then I still decided ordering the MMU3 and hope it won't cause any issues. To be fair I print with support quite a lot and this is the reason I bought the MMU3 to be able to print the support interface with a different material (like PLA with PETG support interface and vice versa) so I will use the MMU3 probably a lot anyway.
RE: Newbie Questions on MMU3
Thanks for the answer Mike, I guess I may put off the MMU3 for a while.
RE: Newbie Questions on MMU3
It is as easy as it could be:
Disable MMU in "settings" and you can print and bypass the MMU as before. Once you want print with the MMU just enable MMU in "settings".
RE: Newbie Questions on MMU3
It is as easy as it could be:
Disable MMU in "settings" and you can print and bypass the MMU as before. Once you want print with the MMU just enable MMU in "settings".
What about the filament sensor that has been disabled in the Nextruder when installing MMU3?
RE: Newbie Questions on MMU3
The filament sensor is modified for mmu3. But still should work as a filament out sensor.
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Newbie Questions on MMU3
The filamentsensor on the nextruder is enabled with or without MMU
RE: Newbie Questions on MMU3
The filament sensor is modified for mmu3. But still should work as a filament out sensor.
The filamentsensor on the nextruder is enabled with or without MMUSo
So what exactly happens then when preparing the Nextruder for MMU3 and removing the filament sensor assembly?
https://help.prusa3d.com/guide/9a-mk4-s-nextruder-mod_683106 (Step 8)
"On top of the Nextruder heatsink, there is a filament sensor assembly. We will need to remove it"
I'm curious since you both state it will continue to work. What exact functionality does this part have then that has to be removed in Step 8?
RE: Newbie Questions on MMU3
In the adaption of the MK4 nextruder to the MMU3, the filamentsensor on the nextruder is changed. There is a filament sensor. The only difference is the mechanical trigger (by ball or by idler movement).
Once you have done the adaption to the MMU3 you need not to change it back if you want to bypass the MMU.
As I wrote: simply disable the MMU3 in the settings. Unplug the tube on the nextruder and load the filament directly to the nextruder.
RE: Newbie Questions on MMU3
Great, thank you!
RE: Newbie Questions on MMU3
Thanks for the answers/discusssion. It looks like the MMU3 wouldn't inhibit the full normal use of the MK4 so I may add the MMU to my MK4S update.
RE: Newbie Questions on MMU3
I tried in the meantime and the only thing different is that the filament sensor in the modified extruder is reacting later due to the way it works after modification.
Later means the remaining filament of a spool getting empty is already at the middle of the gear or so before the printer can react to it which means pulling can be a bit more tricky (I did some tests only, no real-life spool getting empty or so).
RE: Newbie Questions on MMU3
Thanks for that test. For me running out of filament is pretty rare although I've had it break a couple of times. The important thing is that the printer will still stop so I don't think it should be OK.
Thanks for you answer on my other query on high flow nozzles, I've been using the standard obxidian nozzles for a while with polymaker PC and LW-PLA as it feels abrasive (although they dont recommend a special nozzle). Havent used conductive filament yet but considered it for rf enclosure.
Cheers,
Paul
RE: Newbie Questions on MMU3
Sorry should have read "The important thing is that the printer will still stop so I think it should be OK."
RE: Newbie Questions on MMU3
Another alternative for Single filament printing. Keeping the MMU active.
For other filaments I run the slicer for a MK4 without MMU. Example ASA single filament.
I load the filament in one of the MMU slots. The MMU doesn't care what the filament is.
When I run the Gcode, the system asks me to select the MMU3 slot for the filament. I go through the procedure to select the filament on the MK4 screen.
System runs. MMU3 loads the filament. It uses the MMU3 sensor to warn of running out of filament. I don't have to worry about pulling it out of the Nextruder when I run out of filament. If it runs out, it "ejects" the filament. I pull the short end section out of the front of the MMU, then continue on to loading the replacement in the MMU3 slot so it will continue the print
Unloads when done
RE: Newbie Questions on MMU3
This is exactly what bothers me as well. I have an MMU2S and the Upgrade Kit ready to assemble. After reading the manual I am a little bit concerned loosing the standalone feature of the MK4. I dont use much different material, the MMU should be for testing and changing materials between different prints. But I dont want to limit myself to using the MMU forever and always. Also I dont want to rebuild the old sensor, of I change my mind.
RE: Newbie Questions on MMU3
I don't know what you're still dealing with here. The modified sensor works independently as well. If you turn off the MMU, disconnect the hose from the Nextruder and give the command to load the filament, the feed gearbox will start to rotate slowly. By inserting the filament, the teeth catch it and pull it down, thus activating the sensor on the extruder. And that's it!
RE: Newbie Questions on MMU3
I don't even have to pull the hose out of the Festo connector, because I have it divided between the MMU and the Nextruder just above the Nextruder and the two parts connected by their own bayonet connector, so disconnecting the hose is very quick and I can connect any piece of other hose leading from a separate filament magazine to the lower part connected to the Nextruder using the second bayonet connector.
RE:
Thank you for your (helpful) input. Please keep in mind, that there are people who just bought their first MMU and are now evaluating how everything works our could work for them. I think the cause of the forum is, to help people like me (or the first author) to adress these issues and get help from more experienced users. Therefor yours and the answers of the other users helped me to understand, that the printer will function without the filament sensor of the extruder. Except for some problems, if the filament runs out, because no sensor is there to detect. That never happend to me befor, so I think I'm fine.
But I definetly think it is ok to "still be dealing with this issue", which is NOT clarified in the manual!
RE: Newbie Questions on MMU3
Therefor yours and the answers of the other users helped me to understand, that the printer will function without the filament sensor of the extruder. Except for some problems, if the filament runs out, because no sensor is there to detect.
Even after modification there is still a sensor in the Nextruder to detect the filament.
It just works different after modifying the nextruder for MMU3. @miroslav.h4 explained it well how the sonsor works after modification.