MMU3 and MK4S issues with filament change and the MMU3 unit
Hello everyone,
I bought the MMU3 unit assembled from Prusa, this would rule out my lack of knowledge on how to build it correctly 🙂
So the unit installed very easily on the MK4S printer. The MMU3 unit worked fine on simple prints with 3 simple colors and not too many filament changes.
I then tried a more complex model with 5 colors and over a 1000 filament changes.... What a nightmare! The MMU3 unit or the extruder, something is messing up the filament change after many hours of printing. I get Finda issues all the time, to fix, I have to take little pieces of filament that the MMU3 unit breaks due to some issue with filament retraction I think?
I then load, and unload the filament, and it goes... the problem is.... every 100 changes the issue happens, and .... this is very work intensive to go there and fix the filament for the MMU3....
I contacted the Prusa support, we did all the calibrations.... then it works... but again if you print that complex model, every 100 changes or so, same issue....
How reliable are these MMU3 units?
RE: MMU3 and MK4S issues with filament change and the MMU3 unit
Hi, welcome to Multi Madness Unlimited! There is a learning curve, but once you get it set up it should be quite reliable. Without knowing exactly what problems you’re having, all I can offer is a few tips.
1. Reduce friction. Make sure your spool holders turn easily. Make sure you don’t have sharp bends in your PTFE tubing; especially the section between the buffer and MMU where the filament gets pushed backwards during a change.
2. Avoid using presliced gcode. The gcode examples kept giving me stuck filament issues, but when I resliced them they ran fine.
Good luck. I hope you like it. The longest multicolor print I’ve made was about 11 hours with over 1000 color changes with no problem.
MK4S/MMU3
RE: MMU3 and MK4S issues with filament change and the MMU3 unit
Hello, Thank you for being brave and answering my post. Do you see any issues with my current setup?
RE: MMU3 and MK4S issues with filament change and the MMU3 unit
Nope, looks like you have a great setup! I have had occasional issues with poorly wound cardboard spools, especially if the filament gets wedged in along one side, but that can happen with or without the MMU. Looks like you have plastic spools (Sunlu?) which should run well. Sorry, that’s all the ideas I have at the moment! Best of luck! Let us know if you find a solution.
MK4S/MMU3
RE: MMU3 and MK4S issues with filament change and the MMU3 unit
This upgrade is now helping to mitigate issues. I will fire another 20 hours print here - multicolor and I will report back !
RE: MMU3 and MK4S issues with filament change and the MMU3 unit
Looks good! That stops the PTFE from being pushed into the dryer, too, right? What mod is that?
MK4S/MMU3
RE: MMU3 and MK4S issues with filament change and the MMU3 unit
Yes, correct.
I got it from https://makerworld.com/en/models/592738-creality-space-pi-pc4-m10-connector?from=search#profileId-514443
RE: MMU3 and MK4S issues with filament change and the MMU3 unit
Trying another complex colored print... same issues
It seems like MMU3 besides all adjustments is not very reliable. I was able to finish a 20 hour print, but had to intervene a dozen times ....
It is really sad that Prusa can't make an AMS like device that is reliable. MMU3 is not like AMS and it is not reliable.