new MK3S and MMU2S  

  RSS
xayoz
(@xayoz)
Eminent Member

So far I am pretty happy with the results, but would like some advice from veteran MMU2S users.

 

Is it possible to get MMU2S as reliable as MK3S?  My MK3S without MMU2S I can set a print and walk away and be confident it will complete.  My MMU2S, however, I am into my 3rd print right now.  A 14 hour print required 3 interventions, another 14 hour print required I think it was 6 interventions, and now I'm 44 hours into a 60 hour print and have required 2 interventions so far.  While I feel that is acceptable, expecially since the print only pauses and keeps the bed hot, so doesn't fail outright, I would like to know if it is possible, and how it is possible, to get to where I can reliably have no interventions.  Will it just wear in?  Do I need to tweak stuff?  Do I need mods?  Or is only a few interventions on a 60 hour print (it's the melting rubik cube btw) pretty much the best I can expect?

 

 

Posted : 08/09/2020 4:46 pm
nikolai.r
(@nikolai-r)
Noble Member

It highly depends on the root cause of  the interventions you have right now. Based on my experience the MMU wears in over time as the tubes are getting wider. The obstacles are getting worn out, so the filament path is running smoother over time.

But it's important to understand why you have interventions right now. Maybe you still need to find a sweet spot for your tension screws. Or maybe the filament temperature is not ideal. This is something you need to adjust.

I see, you're using the original filament buffer. This can be also one of the root causes.

Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram...
Posted : 09/09/2020 6:24 pm
xayoz
(@xayoz)
Eminent Member

Every intervention is the same for me.  I have to push filament back into the PTFE, click the middle button, and tap on the selector while it is unloading.  Only thing that makes sense to me is that maybe the ball bearing is not dropping away from the FINDA as intended in a reliable manner.

Posted : 09/09/2020 6:42 pm
nikolai.r
(@nikolai-r)
Noble Member

Good observation.

1. Check the FINDA, ball and the space where the ball reside is clean and dry. Don't add any lubricant or something similar. Try to smooth the area, so the ball can move better.
2. If everything looks fine, raise the FINDA by one rotation (check it's still triggers). Sometimes it helps if the ball have more room to move.

Edit: Leftovers from filament tips like to stay under the ball. If you find tiny filament hairs, then adjust the filament temp. to avoid it

This post was modified 1 month ago by nikolai.r
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram...
Posted : 09/09/2020 6:51 pm
nikolai.r
(@nikolai-r)
Noble Member

One more hint in regards to that. If you print less then 5 colors, try to use filament inputs far away from each other.

For example 1:5 for two colors, 1:3:5 for 3 colors. This way the filament leftovers are being pulled out better from the FINDA.

Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram...
Posted : 09/09/2020 6:56 pm
xayoz
(@xayoz)
Eminent Member

thanks for the suggestions.  I actually printed this https://www.prusaprinters.org/prints/28540-mmu2-selector-with-magnet-and-windows

and my first print with it was 3 hr with 1 intervention, then it seemed to work itself in.  After that first print I did a 3 hr, and a 9.5 hr both with no intervention.  Hopefully the issue is solved.  Next will be figuring out the intermittent burnt filament drops on both machines.  Thinking I may have to lower temps 5 or 10.

Posted : 10/09/2020 5:21 pm
nikolai.r liked
xayoz
(@xayoz)
Eminent Member

yep, was printing for the last 24 hours straight with no interventions.  Many colour changes side by side, etc.

Posted : 11/09/2020 5:58 pm
Share:

Please Login or Register