MMU3: How well is it working for you?  

RE:

There is an alpha firmware that was released recently to fix this. So far its been resolved for me after getting the alpha off their github

RE: MMU3: How well is it working for you?

Not well, on filament 1, it does not retract sufficiently, all others are OK, so, the cutter cuts about 1/8 of the filament every time it changes filaments, eventually it winds up jamming the selector. I've heard there is a 'filament retraction' procedure, but that seems only to be relevant to the the extruder extraction procedure.

RE: MMU3: How well is it working for you?

I had bought an MMU2S together with my MK3S in 2020, but I had never assembled it so far. When I got the MK4S upgrade for my MK4 I added the MMU3 upgrade kit for the MMU2S without printed parts. After the MK4S upgrade was finished I printed the MMU3 parts and started assembling the unit. Yesterday I had everything completed and was astonished how well the system setup worked without any fiddling with the settings or even having to take apart again something to get it to work. Instead of the buffer I use these auto rewind spool holders. They are easy to print and I have been using them without MMU for years. 5 of them fit on top of the enclosure. Those are the ptfe tubes that come out of the MMU3 in the enclosure below. I also have found a variant of these spool holders for hanging on the wall. Those would take up even less space. This setup seems okay for PLA, for PTFE I would have to find a solution with a drybox to put them in. I am still tuning the necessary weight on the retract mechanisms, but I am getting there. 🙂

RE:

Posted by: @walter-layher

Instead of the buffer I use these auto rewind spool holders. They are easy to print and I have been using them without MMU for years.  …  I am still tuning the necessary weight on the retract mechanisms, but I am getting there.

I tried a few rewinders but gave up on the constant re-tuning.  The Prusa Buffer works fine for me.  MK4S/MMU3

RE: MMU3: How well is it working for you?

I use them too and like them. I've design a small modification so they are much quieter:

https://www.printables.com/model/414807-quieter-rewinder-track

RE: MMU3: How well is it working for you?

I have used them so far for their tangle-free functionality and only with one-way-operation. Now I have to find out how much more weight is needed for reliable retraction. I don't expect that this will need much re-tuning after that. I am a bit sceptical about the rewinders that use 3d-printed spring mechanisms. I expect they will not last forever and degrade over time.

RE: MMU3: How well is it working for you?

You designed those? Thanks! I have already discovered them and have been using them for some time. 🙂

RE: MMU3: How well is it working for you?

Ah nice, glad you like it!

RE: MMU3: How well is it working for you?

Never used MMU before. I changed my mind when I refused to buy a BambuLabs printer with AMS. 

I decided to give Prusa a chance with a MK4S and MMU3. I received the unit today, fully assembled, very nice. You still have to do some assembly (like modify the Nextruder) but nothing hard. 

Pre-loading the MMU3 is a pain. It is not hard, in fact it is pretty simple when you understand what needs to happen. Not for the average Joe. All working now.

Is it the best experience ? NO

Does it work? Yes, pretty good when all is loaded and ready

Does it waste less filament? If you are suing a HF nozzle not sure, but on a standard nozzle YES for sure!

Prusa should invest some R&D on something more user friendly such as AMS or AMS2  from BambuLabs 

This is my first day using MMU3, not sure how reliable this is, how to fix any potential issues, but it is definitely not something for large scale deployment.  

RE: MMU3: How well is it working for you?

MK4S + MMU3 + Enclosure

PAIN IN A ASS: Always something get bad during printing: filament coil around the idler and not loading, Pinda not detecting filament, ... many many problem !!!

At the point, most of my printing are without the MMU !

Now I suspect Prusa do let the MMU go out to force customers to turn to the XL.

RE: MMU3: How well is it working for you?

3rd day with MMU3. 

That crap works! It is not fool proof, it requires skill, understand how everything works, and a lot of patience to load and unload filaments.

Think of it as a 89 Volkswagen! 

I have some picture of my setup:

RE: MMU3: How well is it working for you?

Posted by: @zfrenchy

MK4S + MMU3 + Enclosure

PAIN IN A ASS: Always something get bad during printing: filament coil around the idler and not loading, Pinda not detecting filament, ... many many problem !!!

At the point, most of my printing are without the MMU !

Now I suspect Prusa do let the MMU go out to force customers to turn to the XL.

 

Check for updated MMU3 parts on Printables.com. After updating mine, all of the old issues were resolved. Works consistently now without problems.

If I have a rare issue it's not caused by MMU3, but by some other component. What spool buffer/rewinder mechanism are you using? 

RE: MMU3: How well is it working for you?

That crap works!

Yeah, it's amazing. After that POS called MMU2 I had given up home for any multi-material solution from Prusa that just works without endless hours of tuning. 

Having said that, so far I've only used it for multi-color prints, same materials. For true multi-material printing I go to my XL.

RE: MMU3: How well is it working for you?

The XL is really out of 90% of people' s budget. 

I agree with you, MMU3 is for multi-color same material. For multi material XL. 

RE: MMU3: How well is it working for you?

I did, and it is where all get fu...-up !

I checked and printed all parts with the latest revision

https://forum.prusa3d.com/forum/original-prusa-i3-mmu3-general-discussion-announcements-and-releases/new-and-updated-parts-f1-r4/

RE: MMU3: How well is it working for you?

here is the list of parts I did re-print:

- pulley body

- selector Finda

- blade holder

- front PTFE

- idler

- ele cover

- pd board cover

RE: MMU3: How well is it working for you?

Posted by: @zfrenchy

here is the list of parts I did re-print:

- pulley body

- selector Finda

- blade holder

- front PTFE

- idler

- ele cover

- pd board cover

It's possible you have an assembly/calibration issue with the newly printed parts. Once I printed the newer R4 selector Finda components and calibrated, it has been rock solid.

https://help.prusa3d.com/guide/5-selector-assembly_357317#357475

I'm also running a Mk3.5s which of course has a different extruder from your Mk4. There could be some different nuances with calibration. 

RE: MMU3: How well is it working for you?

Were you getting the error: IDLER CANNOT HOME?

RE: MMU3: How well is it working for you?

On the whole, pretty well. No mods required, fits nicely into my negative pressure, home print chamber. I did encounter the overcurrent issue occasionally in the beginning - since upgrading the firmware, haven't seen it since. 

I started with the MMU2, which took a lot of patience to get tuned and running. This one just works. While feed errors / mechanical errors are possible , I find they are rare, and haven't lost more than 2-3 prints this way since I built and installed it almost a year ago.

RE: MMU3: How well is it working for you?

[touch wood] its always worked fine for me. A few snagging issues when loading sometimes, but considering thats not something I do very often, otherwise I'm confident in starting a print and leaving it, knowing I'll come back to a completed model.....