Unexplainable behavior of MMU2  

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Dutch
(@dutch)
Active Member

Hello,

We have the Mk3s with MMU2s unit for approximately one year now.

We had our highs and our lows, but the MMU always been a horrible device, as stated by many on this forum as well. We had some minor modifications based on tips here, and some improved the working of it, and made it usable.

Lately, we have so many odd behavior of the MMU that i can only conclude the electronics must be broken.

Its erratic and unexplainable.

Random loads and unloads, bearing wheel not on filament gears, filament selectror going left right left right left right left right and give all-led's-blink error, radom blinking orange, mid-print stops without reason, etc.etc.

I litterally tried everything for the past 2 months, based on all tips given here, but its a disaster machine.

 

I installed a LED on the filament sensor below in order to see if this would help, and it does. Its very clear when filament is detected and when not, and made me aware that the way the infeed of filament is created is one big design flaw. I put a few drops of quick glue on the parts when the position was correct in order to fixate it, and it made the printer a little less unusable.

 

I have to say that at the moment the printer (or better said: the MMU) is making life so miserable that i almost threw it into the trash yesterday...

Im at the end of my capabilities, and i need some advice/help.

 

Anyone?

 

Thanks.

...
Posted : 26/01/2021 8:58 pm
karl-herbert
(@karl-herbert)
Illustrious Member
Posted by: @dutch

Hello,

We have the Mk3s with MMU2s unit for approximately one year now.

We had our highs and our lows, but the MMU always been a horrible device, as stated by many on this forum as well. We had some minor modifications based on tips here, and some improved the working of it, and made it usable.

Lately, we have so many odd behavior of the MMU that i can only conclude the electronics must be broken.

Its erratic and unexplainable.

Random loads and unloads, bearing wheel not on filament gears, filament selectror going left right left right left right left right and give all-led's-blink error, radom blinking orange, mid-print stops without reason, etc.etc.

I litterally tried everything for the past 2 months, based on all tips given here, but its a disaster machine.

 

I installed a LED on the filament sensor below in order to see if this would help, and it does. Its very clear when filament is detected and when not, and made me aware that the way the infeed of filament is created is one big design flaw. I put a few drops of quick glue on the parts when the position was correct in order to fixate it, and it made the printer a little less unusable.

 

I have to say that at the moment the printer (or better said: the MMU) is making life so miserable that i almost threw it into the trash yesterday...

Im at the end of my capabilities, and i need some advice/help.

 

Anyone?

 

Thanks.

My MMU2 behaved similarly crazy some time ago. Checking all electrical connections, precise cleaning, readjusting the sensor etc. did not help. Finally I replaced the MMU2 board and the errors were gone. I then glued heat sinks to the driver components on the new board and mounted a fan. For further status control, I have, as with the filament sensor, also mounted a LED on the MMU2 to control the sensor status.

The MMU2 is known for its difficult handling and requires a lot of patience. I don't use this for multi-material prints, only to change the filament spool.

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 26/01/2021 9:25 pm
Dutch liked
Dutch
(@dutch)
Active Member

How dit you get your MMU2 electronic board? Was it a warranty replacement?

 

...
Posted : 26/01/2021 10:01 pm
karl-herbert
(@karl-herbert)
Illustrious Member

@dutch

I bought the board at Prusa because the warranty period had unfortunately already expired. But the board is also available at Aliexpress, if Prusa can not deliver: MMU2 board

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 26/01/2021 10:07 pm
Dutch
(@dutch)
Active Member

i hope prusa support chimes in...

hint...

 

...
Posted : 27/01/2021 10:54 am
Dutch
(@dutch)
Active Member

Well, i think it sucks that prusa doesnt care at all. Its been a week and no response.

 

shitty attitude, they're the same as all the other apparently.

...
Posted : 30/01/2021 8:47 pm
karl-herbert
(@karl-herbert)
Illustrious Member

@dutch

Have you ever tried it via chat? Just log in with your Prusa account and select the eshop. After a few seconds the chat window should appear on the lower right corner. If the chat window does not open, disable a possibly activated adblocker or try another browser.

 
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 30/01/2021 11:27 pm
Dutch
(@dutch)
Active Member

@karl-herbert

i tried but never got it.. I do have a adblocker though. i'll take a look again.

 

...
Posted : 31/01/2021 12:02 am
karl-herbert
(@karl-herbert)
Illustrious Member

@dutch

Firefox does not open the chat window for me either. With google chrome browser it works.

 

 

 
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 31/01/2021 1:31 am
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