MK4 / MK3.5 / MK3.9 / MMU3 Announced!  

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

Posted by: @4xs

The purge block is too small for the Buzz print in promo. Is that optimization or just the way the model is?

Purge blocks can be freely defined in the Slicer. I don't think the MMU3 will be very different in that regard to the MMu2s. The amount of flushing you need for a colour change, depends on the specific filaments used and their colour. You basically have to try that out and see how much you need. It also depends on the precise internal geometry of your nozzle. Rule of thumb: if you go to some bright colour or even to white, flush 2 or better 3 times as much as for other colour changes. Standard settings in the slicer are often a bit optimistic and maybe you want to flush 50% more for all change right from the start. 

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

Add me to the "curious as to how hard it'll be to install the MMU3" crowd.  I'm also interested to know if the MMU2s is compatible with the MK3.9.  Assuming the MK3.9 upgrade ships before the MMU3 upgrade (based off of the fact that you can at least buy the MK3.9 while you can't yet order the MMU3 upgrade), I'm wondering if I can/should move the MMU2s over to the MK3.9 during the interim, wait to do both upgrades at the same time (assuming there won't be much of a gap between the two), or just do without a MMU for a bit.

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

@mikicab

MMU3 for Mk3 Is slightly different as for mk4. They differ in printer/ mmu connection cable and the FS upgrade parts.

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

Posted by: @thejiral

 

Posted by: @grant-stein

I think I can speak on behalf of a majority of MMU2S owners that it is a huge disappointment and an extremely poor product. Even after dozens of hours of tinkering, upgrades, and changes it can still barely function. What assurance do we have that the MMU3 is any better? The MMU2S went through "months of testing" and "over 600,000 tool changes". What truly differentiates the MMU3 from the disaster that was the MMU2S? I see there's "improved parts and electronics", but what does that even mean?

If the MMU2 barely functions, you haven't dialed it in correctly or identified your issues sufficiently. Very few if any upgrades are strictly necessary to get an MMU up and running reliably. The only mod I would wholeheartedly recommend is changing the bowden tubing from MMU to Extruder to a slightly wider inner diameter. I haven't seen any disadvantage to that and it makes "fat filament tips" a complete non-issue.

I think the main issue with the MMU is wrong expectations and that Prusa Marketing did not set the expectations right. The MMU2s is a tool that needs to be properly dialed in and people need to be ready to do some trouble shooting, and getting to understand the tool well enough. Once that is done, it actually works flawlessly and reliably. Contrary to rumors if you are lucky the MMU2s can also work like that right from the start, but you can not take that for granted. Some dialing in might be required. 

The massive change for the MMU3 is that the MMU can no communicate two ways with the printer. That means the extremely crytpic error messages (with light signals) can now be now made non-cryptic via clear error message on the screen. Also because of the two communication, certain issues can be resolved by some printer routines, previously not possible due to the lack of communication. There seem to be also some hardware changes but I don't know in how far they will matter. 

The MMU2 is jacked, let me count the ways…

-The spindle turning mechanism is completely inadequate for the job.

-You can’t take the spindle out without tearing apart the base

-The motor mount screws need a special wrench to tighten down

-The sensors fail intermittently 

-The filament guides are not really spaced right

-I spent 10s of hours getting it to physically work.  I understand how it is supposed to work.

Mine is simply possessed.  It just doesn’t work on the electronics side.   Doesn’t know where it is, even after banging on the ends.  I’d replace the board on it, but that I don’t want to rebuild the thing again.

I agree, it SHOULD work.  The concept is sound, but it is just not fault tolerant, easy to get ‘lost’, and not reliable.

I really wish they had just used direct drive motors for each filament- even if that restricted it to less than five filaments.   4 would be nice, 3 would work, even just two that worked well would be better.

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

The MMU2S most definitely requires more effort of the user than the MK3* printer kits!

It requires a LOT of patience, ability and willingness to read between the lines of TFM, mechanical and electrical/electronic aptitude, attention to detail, etc.

It has a much steeper learning curve than the printers do, by far.

To get one that's easy to use, some tweaks and mods are almost imperative.  (Thumb screws, Bowden fittings, power cut-off, etc.)

Once it's working, it will do its job, within its limitations, very well.  Yes, you do give up real estate for the wipe tower and the process does waste filament.

Having said that, I seldom use the MMU anymore, since I got a second printer with dual extruders.  I use the MMU when I need to do a print with three colors.

When I do use it I'll take it out of the enclosure, place it on the floor of the spare bedroom, and use the space behind the printer as a filament buffer.  9 times out of 10 it will do a multi-color print successfully on the first attempt.

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

I may have missed it ( know it's early and not all info is available yet), but does anyone know if the MMU2S upgrade to the MMU3 results in an identical version to buying a new MMU3?

My current MMU2S runs perfectly on my MK3S+, but my MK4 is arriving this week and I'm trying to decide if I should leave the MMU2S on my MK3 and simply put a new one on the MK4, or upgrade the one on the MK3 and move it over to the MK4.  Cost is not a concern but due to space concerns, just one MMU setup would be best for me.

Teamwork,

Steve

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

I have spent many hours and upgraded parts on my MMU2S and the MK3S+ to get the MMU2S reliable.   Mainly opening channel sizes or adding tapered guides to the various parts.   The problem of identifying and clearing errors in the MMU2S is still a problem.  The MMU3 notes look like the upgrade will help clearing errors.  I will be interested to see what parts changed. 

The main problem I still have is the filament break in the MK3S+.  An end jams because it is still hot when going thru the rollers and jams being pulled out.   Reliability of the pull out varies by color in my experience.  With the right color combinations, it can be reliable.   I hope break/pullout has been improved in the MK4.    It needs to be 100 percent reliable for the MMU to work for multi color prints.    

 My MK3S+ and MMU2S notes.

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

I cannot disagree with your personal experience, however for my experience the MMU itself works exactly as it should.  It is the filament unload process that creates almost all the issues.  So, if you did not have an MMU attached but manually unloaded the filament as many times as an MMU project would take, you would run into the same type of issues.  Getting the best unload for your setup is the key.

I found for myself that I try to use PLA filaments from the same company (or different companies that rate the temp range the same) and ensure they are dry.  

My MK3S+/MMU2S is a stock machine with no hardware of PrusaSlicer user changes other than using festos instead of screws for PTFE connections and setting the print temp at the lower end of the range for my filaments.  I'm also using the Lack enclosure with the filaments on top that Prusa posted.

Again, I'm just relating my experience and not trying to imply you are doing anything wrong.

Teamwork,

Steve

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

I strongly disagree with those saying that enough tinkering with the MMU2 can make it print reliably. There are so many people having issues with and so few claiming success that I suspect the people having success are just incredibly lucky.  We are not all bad at tinkering and figuring out why stuff doesn't work.  I've replaced various parts and tubing and tried a different model extruder and pretty much every single suggestion on these forums and have had no consistent success.   I think I've printed three tiny two-filament models successfully without operator intervention in some form, a couple dozen with moderate operator intervention, and many, many hundreds of failed attempts.  I was lucky to be able to reliably print single filament models through the MMU2!  I *finally* gave up and uninstalled the MMU2 entirely to get back my super-reliable printer and that is of course the day before I saw the MMU3 announcement.

So I've pulled the MMU2 out of my trash barrel (literally, I didn't even want the cursed spare parts off of it!) and I'll be trying the MMU2-> MMU3 kit since it's cheap enough but if it doesn't work with a reasonable amount of tinkering it's going back in the trash.

I do look forward to a five-head XL when they're shipping and my name comes up on their list.

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

it works ok if you stick within it's limitations.   I would not say it's reliable however.   I never ever count on it to work.   I'm probably just going to rely on the 5 extruder xl when it arrives for my multi material/color prints.  MMU is a kludge at best and if you stick with PLA and PVA/BVOH it kind of works ok.  again it's very filament dependent though,  Relying on the tips to be shaped perfectly when they get pulled from the extruder is really IMHO what makes it a kludge.

Posted by: @tori-berger

I strongly disagree with those saying that enough tinkering with the MMU2 can make it print reliably. There are so many people having issues with and so few claiming success that I suspect the people having success are just incredibly lucky.  We are not all bad at tinkering and figuring out why stuff doesn't work.  I've replaced various parts and tubing and tried a different model extruder and pretty much every single suggestion on these forums and have had no consistent success.   I think I've printed three tiny two-filament models successfully without operator intervention in some form, a couple dozen with moderate operator intervention, and many, many hundreds of failed attempts.  I was lucky to be able to reliably print single filament models through the MMU2!  I *finally* gave up and uninstalled the MMU2 entirely to get back my super-reliable printer and that is of course the day before I saw the MMU3 announcement.

So I've pulled the MMU2 out of my trash barrel (literally, I didn't even want the cursed spare parts off of it!) and I'll be trying the MMU2-> MMU3 kit since it's cheap enough but if it doesn't work with a reasonable amount of tinkering it's going back in the trash.

I do look forward to a five-head XL when they're shipping and my name comes up on their list.

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

What's the update on MMU3 Release???  As per your webpage dated back in March "In two weeks"  But yet its now 4 weeks on and nothing.

All we ask is to be kept up to date.

RE:

@ra-2-storm

When I can get it?

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

Hi Rene,

That does not help,  We have seen this page and has not changed since March. It only states shipping in June, but one still needs to be able to order it and download the parts.

RISPONDI: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

Troubleshooting ... composition ... I am buying equipment that is supposed execute a job, not a puzzle game!

I can be OK with troubleshooting and compositing if I want to modify it, but if I'm just going to use it the way it's supposed to work, it MUST do its job, without tens of hours of studying.

We are buying an MMU, not a Rubik's cube.

Already the MK4 is only a vague promise of (little) approaching what the competition has been doing for a year, if this version of the MMU also fails, IMO, they will lose the very limited credibility they have left ... and another customer!

Let me add that the promised two weeks that we have been waiting for for 8 weeks does not play in Prusa's favor.

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

Maybe I was the lucky one but I have been running the MMU2S for over a year and apart from a few issues when reloading new filament spools it runs and prints perfectly - can be a bit wasteful of filament on prints but thats not its fault.  I dont use the supplied buffer but a printed tower version I found and that + printer all fit nicely inside the Prusa Enclosure. 

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

Hello everyone!

I have a now broken mmu2s with which I was able to print multicoloured pla objects for a while, but I've never printed petg.Is it also possible to print multicoloured petg objects or is it more difficult?

Have a nice day!

F. (from France)

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

Posted by: @myf

Hello everyone!

I have a now broken mmu2s with which I was able to print multicoloured pla objects for a while, but I've never printed petg.Is it also possible to print multicoloured petg objects or is it more difficult?

Have a nice day!

 

F. (from France)

With MMU3 you can.

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

Using PETG is even easier that PLA.  I pretty much never use PLA unless I have some scrap filament laying around.

As for the MMU2/3  They are both compatible with PLA and PETG.  I am hoping the MMU3 will be even better at handling flexible TPU.

RE:

I can confirm. Printin with PETG on the MMU works at least as fine as with PLA (on the MMU2s certainly as well). Just make sure you use a well dialed in profile and get clean tips without stringing. 

I doubt the MMU3 will be any good with TPU though. That is a more fundamental challenge, than what the upgrade can resolve. But what do I know, maybe tweaking the firmware for TPU could make it at least somewhat usable. 

RE: MK4 / MK3.5 / MK3.9 / MMU3 Announced!

I can't emphasize enough the importance of "clean tips without stringing". I probably spent a weekend (or two) dialing in my settings so that I can reliably manage multiple color changes with PETG. Even with that, prints with frequent tool changes can and will get obstruction faults due to thin string filaments ghost triggering the PINDA sensor.

If you decide to go down this route, I advise:

1) Set your PINDA high enough so that it does trigger when the bulk of the filament is in the selector but does NOT trigger on a narrow string.

2) Make sure that the razor blade filament slicer is new and sharp

3) Experiment with settings for extra loading distance, temperature, and cooling parameters (filament properties). These threads do a pretty good job of explaining why ( https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-assembly-and-first-prints-troubleshooting/mmu2s-petg-success/, https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-general-discussion-announcements-and-releases/mmu2s-petg-pva-does-not-work/, https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-general-discussion-announcements-and-releases/mmu2-real-multi-material/paged/2/)

What worked for me (with prusament PETG) was:

* Nozzle temp: 245

* Extra loading distance (-18)

* Delay after unloading (8s)

* Number of cooling moves (3)

* Speed of the first cooling move (1)

* Speed of the last cooling move (20)

(as a bonus, and a favor: if you can get the good folks at Prusa to tell you the equivalent settings that they use by default on unload, use those and please post here. My own settings work alright, but don't produce anything like the neat snub tips I see from that simple operation)