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Initial MKS3 MMU3 print results  

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mgantner
(@mgantner)
Eminent Member
Initial MKS3 MMU3 print results

pgraded to MMU3 from the MMU2S on a MK3S. I also upgraded to the Superpinda, so almost a MKS3+.

Did a 3 color 60 hour PETG print with 860 filament changes. Two issues were resolved early on and the last 42 hours of the print went uneventful.

First issue - I was using Prusament for two of the colors and another brand for the 3rd(can't recall which atm). The print started with a hotend temp of 230 and I was getting long strands on the tip of the non-prusa filament which was clogging up the MMU3. I adjusted the hotend temp down to 225 and got good tips on all three. No more clogging problems.

Second issue: I had two MMU3 errors within the first 8 hours where the filament was not detected in the MMU3. With help from a post on this forum, I tracked the problem down to having the MMU3 pinda down too close to the ball. This causes a slight delay in sensing the end of the filament and it retracts too far and beyond the gears. Then the gears can no longer grab the filament. I adjusted the MMU pinda up and farther from the ball, increasing the speed at which the end of the filament is detected, which fixed the problem.

The last 40+ hours or so the MMU3 worked flawlessly. I was initially a little nervous that the MMU3 was going to be a problem like the MMU2, but it appears to be a big improvement. Initial tweaks need to be made, but it seems once things are dialed in it is working better than it's predecessor. There's no doubt that the LCD screen messages are a massive help compared to the MMU2S where most of the time I had no idea why it had an error.

Happy to be printing multicolor again!

Posted : 14/12/2023 4:26 pm
Myf and JustMe3D liked
JustMe3D
(@justme3d)
Honorable Member
RE: Initial MKS3 MMU3 print results

Thanks for the report. I´m sure I´ll refer to it again when I assemble my MMU3 over the holidays.

Cheers

Chris

I try to give answers to the best of my ability, but I am not a 3D printing pro by any means, and anything you do you do at your own risk. BTW: I have no food for…

Posted : 14/12/2023 6:26 pm
mgantner liked
redalert11
(@redalert11)
Active Member
RE: Initial MKS3 MMU3 print results

I'm newb when it comes to printing. but I found that the MMU3 works pretty good. I have noticed that there have been a couple jams when their is a color change. the filament has a blob from the previous unload that prevents it from loading. the MMU3 catches this after failing to load and then cuts it off. it will then load the filament and continue to print.

the stringing in the below picture is from the filament not being dry. for me drying the filament elements all stringing.

Issues
my print files say that they are corrupted. I read that this is will be fixed in the next patch.
the cassette does not fit that well in the Prusa enclosure. I'm still looking for a good solution to this.

Posted : 30/12/2023 9:45 pm
mgantner and MikiCab liked
dave2007
(@dave2007)
New Member
RE: Initial MKS3 MMU3 print results

Cannot tell you how envious I am when I read success stories like these, I must 20hours deep and still not one uneventful print... 

Posted : 22/02/2024 10:11 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Initial MKS3 MMU3 print results

Hi Dave, What is happening?

Have you built the MMU3 to the assembly Manual?

Adjustment of the filament sensor, Finda and MMU 3 Idler housing are Critical!

did you use a prusa kit? or assemble your own parts?

Joan

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

Posted : 22/02/2024 11:22 pm
dave2007
(@dave2007)
New Member
RE: Initial MKS3 MMU3 print results

I upgraded from the mmu2s to mmu3, I printed the parts myself but printed on the mk4 .

I have "upgraded" the hot end to revo 6 which maybe a mistake, I've changed the ptfe tubes to 3mm id 4mm od, 

I just cannot seem to get the tips right, I've changed cooling moves etc and speed, sometimes it won't load a filament five times but just pressing the knob then it loads. I would say I have everything setup up correctly.

 

I've just ordered prusa fillament incase it was that .

 

Any help would be gllreatky appreciated.

Posted : 23/02/2024 7:09 am
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Initial MKS3 MMU3 print results

What are your filament tips like? 

Have you changed your Extruder internal PTFE recently? that is part of the tip forming process
Are you using the correct PTFE. it's not 2mm x 4mm, but 1.85mm x 4mm for the MMU extruder
https://help.prusa3d.com/guide/how-to-trim-ptfe-tube-multi-material_108480

If you can't find that PTFE, Capricorn XS May be an option 
https://www.en3dstudios.com/product/capricorn-pfte-bowden-tube-xs-series-100cm-id1-9mm-od4-0mm-2/

Are you getting long strings on your tips?   If so, reducing Extruder temperature a little may help

can you observe the sensor status as your filament loads?       (I have modified my Filament sensor to have an LED  that shows status) 

I added a 5Volt LED to the filament sensor, like this  (Yep, I know this is not a MMU Setup, it's the picture of my other Mk3S, for information only)

The LED Gives an instantaneous indication of filament status, ALL OF THE TIME... no messing about with LCD Menu's

You can get LED enabled Filament Sensors, Here 

https://zaribo.com/sensors/546-zaribo-smart-prusa-filament-sensor-for-3d-printers.html

using this LED I noticed two issues... 

1, if the sensor tower is 'On the edge' of adjustment, it can flicker during loading, which will cause a load failure!  Cure, re adjust filament sensor to make the change more positive
2, If you have had a  filament jam, and you have not trimmed off the damaged filament (where the bondtech hobbed gear, or the MMU Pulley has worn the filament)
the filament will load, then the filament sensor will sense the worn section of filament and cause an unload...   this can be quite frustrating, especially if also subject to issue 1, in which case very minor wear, can cause a rejection

when the MMU3 pulley motor rotates, do you get a clunking noise? 
I had this problem on a working MMU3, the Pulley motor wire failed, so I got a new Pulley motor. and the 'Flat' on the shaft, was not as deep, as the old motor, this caused the grub screws for the pulleys, to stick up a little taller, and bump  the mmu3 Idler roller as it passed... I had to move the idler assembly a little further over, on the idler motor shaft, to give clearance...  
I hope this helps. 

regards Joan

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

Posted : 23/02/2024 11:23 am
dave2007
(@dave2007)
New Member
RE: Initial MKS3 MMU3 print results

Yes I changed the hot end ptfe tube with the one that came in the mmu3 kit, it's 1.85mm I believe.  I changed the buffer ptfe tubes to 3mm internal diameter for less friction as a few yt videos suggested this would be a good idea, the tube between the filament sensor and the mmu3 was also changed to the 1 .85mm one provided by prusa.

The tips are a little stringy now with cooling moves on 5, and this really adds time to the print. My temp is down to 190 I tried lower but got a few jams so 190 is about the lowest I can go on pla.

I will observe the fil sensor and see if I get any flickering,  as for clunking on the mmu I don't think I do it all seems smooth, but I will pay attention and observe, I will also look into the led idea as that's a great visual aid for loading, thanks for all you help. 

 

 

Posted : 23/02/2024 12:05 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Initial MKS3 MMU3 print results

My Pleasure Dave

I have been using MMU  for years... 

I did my latest MMU1 print Last night...   That setup is about 6 years old, 
the Other Machine has been 

Mk3 MMU2
Mk3S MMU2S
Mk3S MMU3
Mk3.9 MMU3... 
and I have also had Mk3S Palette2S Pro

Been a bit busy!

🙂

Joan

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

Posted : 23/02/2024 12:12 pm
dave2007
(@dave2007)
New Member
RE: Initial MKS3 MMU3 print results

Can you think if there are any settings in slicer I need to change due to revo6 hotend .. cooling position etc? 

I have played with ramming settings but got jams 

Posted : 23/02/2024 12:34 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Initial MKS3 MMU3 print results

Revo, is supposed to be a drop in replacement for V6.  never tried it with MMU

I believe you have been trying all sorts of things to sort the MMU. 
could you have over complicated the issue? 
did you do ramming, before temperature?   Could it be, that undoing the ramming, will speed things up, and reduce the clogs? 
when 'Fixing' things, it's wise to review, what you have tried, in case the changes interfere with each other... 
My MMU3 is working with Standard Settings... no changes to ramming. 

Filament temperatures are always a bit of a playground. 
do you use above default retractions? I typically use below default retractions  0.4mm in most instances (PLA and PETG)

Is your left hand fan a standard Prusa Fan? Non prusa fans can cause issues, there is a hidden experimental menu, that can help sort non standard fan issues... I have never tried using the alternative settings with a standard fan. 

when you get a clog, what do the filament tips / ends look like@ do you have pictures? 

can you add pictures of your hot end / extruder from different angles as well please, this may help identify issues. 

regards Joan

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

Posted : 23/02/2024 12:52 pm
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