MMU2S Theory of Operation
ฝัง
- เผยแพร่เมื่อ 14 มิ.ย. 2024
- After gaining some experience tuning the MMU2S, I decided to record this video detailing the usage of the MMU2S, the logic of it's operation, and troubleshooting when issues come up.
Chapters:
00:00 Intro
00:45 MMU2S Hardware Review
03:54 Hardware: Buttons & LEDs
09:54 Hardware: MMU2S Extruder
11:00 Filament Loading & Unloading
18:56 Operational Fundamentals
22:41 Intermission
23:57 Basics of Exception Handling
25:40 Mitigating Exceptions
32:23 Exception Mitigation Review
33:55 Handling Edge Cases
37:24 Common Issues
38:16 Critical Points
38:57 MMU2S Part Updates
41:42 Final Words
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This is the best explanation of the mmu I've come across. I haven't decided to pull the trigger yet, but this is so helpful
This video is unbelievably helpful. Best video on the tube I’ve seen.
This is "THE MMU HANDBOOK", this piece of treasure should get verified by Prusa and put into the Prusa Knowledge Base.
So detailed and clear, and this guy KNOWS what specific movement I was looking for in every section of the operation.
My unit is not yet arrived, but I feel like I've been tinkering MMU2s for some time, amazing video for sure.
This video should be included in the MMU manual.
I have just guessed what the buttons do in different modes and what the blinking means and found out most of by trial and error...
Wish I had seen this video earlier, preferably before I bought the MMU to begin with.
Thanks, that was worth my 30 hours of frustration learning by experience.
Well, this video made the MMU2S a lot less scary than what most forum entries let me think about it. Thank you! I think I'll get one in the future.
Probably the best video explaining how this unit actually works. Thanks for making this! I will get this upgrade at some point for sure.
Best description of the MMU2 that I have seen anywhere. Well done. Looking forward to viewing the videos on how to actually print with this thing.
Great video! Wish I had seen this prior to struggling with my MMU2S’ first few prints. Learned a lot and will use this as a reference in the future.
Great, amazing... no words for such a video! Well done. Thank you for this huge and great explanation.
this is better than prusas documentation itself!
this needs to be a sticky on the MMU2S handbook
Fantastic video, super clear and well organized. A must for anyone interested in the MMU2S
Thank you for this clear explanation!
WOW, that was a great video taking the mystery out of the MMU. Bravo and glad I found your channel.
Prusa should have released this quality video, excellent explanations, thank you
Very good video and even better advice, thank you so much! This will go a long way into getting my MMU2s operating reliably.
Excellent video. Thanks for making such a thorough video on the MMU. If you get a Voron ERCF please do a similar video on that.
Awesome content! Can’t wait for my MMU2S to arrive this Friday.
Excellent In-Depth overview! I have had my MMU for over 6 months with little to no success as a result of non-intuitive LED status. (not to mention the Red and Green look nearly identical). After watching this, I am going to delve back into it since better understanding the status. Thanks for posting!
If you need a hand, let us know.
My MMU is about to arrive, and I’m red/green colourblind. Are you too? Or am I going to have an even worse time than you? Did you work out ways around this?
Awesome. Never understood how this mmu2 works till today!
Thanks man for this video. Exactly what I was looking for
best explanation and tips that make my life much easier. Thanks, Lee!
Outstanding information-thank you very much ✅👍
great instructional video , thank you !
Great video, thanks!
Verry helpfull and clear video! Also can't wait until mine arrive ;-)
I have a love/hate relationship with my MMU2, mainly because of the hit and miss of getting a good tip for a successful unload and reload. An explanation into the settings of the slicer mysteries would be extremely helpful.
Fantastic video - thank you. I finished building my MMU2 but wasn't really sure how it was meant to work. The Prusa assembly instructions are very good but they leave you at the end without any explanation how to get it working. Your video explains everything so clearly. I made my first print and it stopped twice with errors. By following your logical troubleshooting workflow I was able to work out what was going on and get the print finished. The problems I had were both related to the spools and I have now worked out how to prevent it happening again. Once again - thanks.
Hey thanks Peter, and for bonus points you can install the only just released MK3S+ MMU2S parts which are backwards compatible with MK3S: new idler door, sensor cover and sensor holder are all interchangeable. 💪🏻🖨👍🏻
@@LA3DPrinterRepair Thanks Lee but I have actually got the Bondtech BMG mosquito extruder so I found an alternative filament sensor for that.
My modified IR filament sensor has an LED which lights when it has triggered. It makes adjustment a breeze and helps debugging. I really dont understand why this feature isn't included in the Prusa version. It might have helped a certain person further down this thread - but I suspect they are beyond reasoning :-)
@@peterharris7682 personally I’m not a fan of 3rd party Prusa mods: I don’t understand the value in adding a BMG extruder, the stock filament drive already uses Bondtech gears and if your hotend requires geared extrusion then there’s likely a problem downstream, any properly maintained E3D v6 can manually hand extrude smoothly with no more force than pushing a spoon into peanut butter, the motor shouldn’t need to “force” the filament.
re: IR Sensor LED, you tune it once via sensor info, unless your machine is getting knocked around there’s no need to increase the BOM count to add an LED when the machine doesn’t care what the LED shows...what if the cable is frayed? Then the LED becomes misleading as an indicator...
Fantastic video! While I have been fairly successful with my MMU2S, this video really helped explain the operations, especially when things need intervention. I’m thinking of doing the MK3S -> MK3S+ upgrade, and will also upgrade the MMU2S parts your highlighted.
MK3S+ is mostly a vanity upgrade, no new functionality, however the MMU2S specific bits: the extruder idler, top-hat and sensor cover from MK3S+ do fit MK3S and are improved parts. 👍🏻
@@LA3DPrinterRepair Hi, great video. I have a MK3S with MMU2S and I'm trying to understand which parts from the MK3S+ you are referring to, I'd like to upgrade mine. Sorry for my lack of understanding. Thanks.
@@GuyH77 Idler door, sensor holder and sensor cover from MK3S+ are interchangeable with MK3S, you can reach out and purchase a printed set from us if you like.
This is a great video outlining the Prusa MMU2 operation. Some of this was fairly self-explanatory from the build process, but the review of troubleshooting and in particular the exception handling portion is exceptionally informative.
Lee, can you comment more on the filament buffer and what you're suggesting as an optimal printing setup? You mentioned the buffer for a second at the beginning, but didn't follow up.
The buffer just makes loading a chore, by using the short buffer tubes on the MMU2S you can much more easily “feed” during load, especially if you give your filament ends a “spear” cut instead of a plain angle cut.
@@LA3DPrinterRepair Do you use some kind of auto-rewind spool holder instead?
@@FrancisEsmondeWhite Negative, the filament tends to "pigtail" naturally behind the machine, I do both dual standard spool holders flanking the MMU2S or just standard "desk" holders a foot or so back from the unit itself.
Fantastic video for diagnosing issues for the MMU2s. I want to ask, why don't you use the buffer and what alternatives have you found to replace its function?
Trent Lau just run the spools above the printer or behind with enough clearance where the ejected length won’t tangle, that’s all the buffer does is contain the filament that’s backed out between swaps.
@@LA3DPrinterRepair So its just about mounting then? Awesome, thanks for the advice!
Great video! Quick question... Did anyone get a printed manual/assembly instruction book with their MMU2?
Mine didn't come with one and support said they didn't have any books left and they wouldn't print more as they didn't plan on making anymore MMU2's (they said this while they were still selling them from their website and before they made it public about discontinuing MMU2) They also said it really wasn't for anyone who wasn't very tech savvy as it had lots of issues. Direct from Prusa support!
Hi Lee, thanks for the great video on the MMU2S. At the beginning of the video, you mentioned you would discuss later in the video your thoughts on the use of the filament buffer for the MMU2S, but I didn't catch where you talked about the buffer and why you don't use it. I would be interested in your opinion of the buffer. Thanks again!
Lee, I just read your comments from other viewers asking the same question. Sorry, I should have read through the comments first. No need to reply. Thx!
@@motoreffpv9073 it's all good, in my experience the natural "pigtail" of the ejected filament between stops is plenty of slack to prevent switching problems - loading "through" the buffer is just tedious and fiddly to the point of frustration, removing it makes the whole operation much more fluid.
@@LA3DPrinterRepair thanks for the Reply Lee, I understand your point. I suppose if you don’t use the buffer you just have to make sure there is plenty of room (and spacing between adjacent pigtails) so they don’t tend to get caught or tangled on each other. Pigtail management basically. Thanks again for your help!
Great video, I'm new to Prusa stuff. I bought a used mk3s+(supposedly) and it came with an MMU2S. It's working fine for single colors and I did not know the Prusa slicing software can stop in the middle of a print so you can change colors, that's super cool. How can I tell if the MMu2s is actually a 2s? Also Your setup has an ir sensor contraption sitting on top of the extruder. Does that come with the MMu2s? mine doesn't have that. What exactly is that part called so I can try to find one, since it looks like it's needed for reliable operation. Thank you for any information.
Hi Tony, maybe reach out directly to get some clarifications; then you can send me some pics and I can figure out what specifically you've got there.
This should be included with the kit and required watching. One Question: Does this mean NOT to filament load to nozzle for multiMaterial, but only for single filament (old gcode?)
Correct, don't load filament to the nozzle unless you're running MK3S gcode.
What control board does the MMU2s use?
Great video, i would also like to add that the spring in the door for the bondtek gear is important, mine does not have the origional spring and are making a lot of trouble for me. i need a new origional spring ;)
Idler spring? Reach out, I’ll get you sorted.
@@LA3DPrinterRepair thank you, i just ordered new idler sping along with a few rolls of prusament petg ;) I Just wanted to mention it if someone else has problems with the filament goes in and out without been picked up by the extruder :-)
Thanks for this very informative video. I just did my first MMU print which went pretty smooth. Only issues I noticed was filament not being pushed through the tube at one point, so I increased the tension on the MMU2S idler a little and one time it did not want to move the selector for a filament swap and started blinking. So in a proper non-manual-reading fashion I pressed the buttons without knowing what else to do and it worked - your video explained why ;-).
Do you know if there is some kind of testing procedure that randomly loads and unloads filaments up to, but not into the extruder? This would be a nice test to make sure the idler tension is ok, sensors are working and such.
PS: The only mod I will probably add is the rear tube holder. The squeezing tube holding mechanism just feels wrong. I'm going to switch to the proper fittings holder for that.
Hey Balu, just a couple turns past where you feel spring tension is correct, loose is bad and tight is bad but the butter zone is wide. Re:testing you want “load to nozzle” and unload, that will do what you’re asking. Happy printing.
@@LA3DPrinterRepair Yeah, it was just an oversight after fixing the positioning of two pulleys. It just needed a turn or two more.
The "load to nozzle" is all manual though. For a stress test and to see if perhaps there is too much resistance in the tubes, spools, not enough tension, etc. it'd be nice if the MMU2S did just randomly load and unload filaments from every slot until I tell it to stop =)
@@ulaB that’s what we call “run a five color print”.
😉👍🏻
@LA3DPrinterRepair Any chance of an MMU3 version of this incredible video tutorial and user resource?
I'll see what I can do.
Man your a stinking genius!! 1 hour ago I was ready to burn $350 and you gave me just enough to keep moving!! I did not see where or why you removed the big black buffer but you did indicate you usually do not use it OR is there a way to show how the correct way of usage would be? Seems as if it could come in handy on the unloading as you can not reverse the spools to keep the filament tight on the roll? Consider an updated software video??
Buffer just makes loading a total pain, do make sure that the buffer tubes are completely seated on the back of the MMU whether you use the short tubes or the long tubes! There is a sort of tight flange under the retainer where they need to be pushed up and in a good 2-3mm (1/8”) to seat properly and prevent hang ups on that final inch of loading.
Nothing against the buffer, I just don’t like the additional footprint and hassle it creates, nor am I convinced by the retracting designs out there.
2.4 is going to completely change the MMU2S landscape so once that drops, it’s probably time!
Hey thanks man, hit me on Twitter or whatever and I’ll kick you some stickers. 🗿👍🏻
Hello, i just stumbled across your video and i wanted to check and see if you have noticed this issue before. My MMU2S keeps having hardware crashes. During a move of any of the axis's the control board will stop all of the lights orange and green will flash. The board will reset and then crash again. this is my second control board (i have limped along with it for a couple years at this point) and its still this issue. When i replaced the control board it seamed to help for about a month. I was thinking about biting the bullet and getting a pallet when i stumbled across this.
I sell a modified MMU2S Signal cable on eBay that has resolved the issue for our customers, pick up one, give it a shot. I'll send you some stickers too!
@@LA3DPrinterRepair I will be sure to try it!
Great video!!! Now if I can just get the filament sensor set right 😔
Thanks Damien, you can always send it out to us!
We don’t just make videos, we stand behind what we do!
Check out the show if you ever have time, by episode 10 it’ll actually be somewhat structured.
damnit... now i want one :/
Here in 2022, are the mmu2s worht the money ? After updates and etc. I consider buying but, after I see how many folks there writing they have problems all the time, are scarying me a little
It's not an abandoned add-on, it's been implied that there are still big updates updates to come on the firmware soon, it's certainly cost effective for what it is.
A big grievance is the orange opaque PTFE tube between the MMU and print head. Why on earth would they not provide a transparent tube for such a critical section to help diagnose any issues easily???????????
Yea, they switched it pretty quickly; if you need a fresh tube and you don't wanna pay shipping all the way from prague, reach out, we're not hard to find.
I don't shovel parts online, lemme know what you need and I'll pull it from stock.
Keep on printing Jake, thanks!
So What's the difference between the MMU2 and mmu2s?
MMU2 didn’t have filament detection at the extruder, and no buffer.
great video, but i had to turn the audio up to max level before I could hear it.
And that's exactly why we are switching to a weekly live format; the treatment these topics deserve cannot be packaged in "cute little videos", even forty minute long productions that took weeks to prepare for.
If you can't hear me on stream, just pop it in the chat and Chris see it and crank me up a bit.
You need help, we help, it's our job.
"It's printing right now." Thursdays 6p pst, you tell us what you want to hear, we'll chew your ears off.
I think one of the most impressive things about Prusa is they don't use any injected parts, all 3D printed, as to say that their printers are good enough to print these parts. All other printers use injected parts and it isn't because their printers don't print parts at high enough precision, it is a cost/speed reason, but still if a printer can't print parts for another printer I'm not sure how much I'd trust it.
It’s called a Reprap: Replicating Rapid Prototyper, and Prusa is by far and away the largest operation working along those principals.
@@LA3DPrinterRepair I knew that but even Chinese printers based on this and reprap designs still use injected parts. Once again for speed and cost but Prusa stays true to reprap.
@@buckettraveler8398 if it’s not printed it’s not a reprap, those are just “cheap 3D printers”, Enders are not RepRaps, they’re Prusa clones.
A 3D Printer can print a reprap but a reprap can only print a 3D printer that’s also a reprap.
Also, the standard Prusa spoolholder is actually injection molded, since ~2018.
Si se tutos pourrait être en Français je serais le plus heureux de monde car même avec le sous titrage google sa va trop trop vite pour bien comprendre.
idex is the answer to remove us from this misery
Do you consider the Prusa XL IDEX? I don't implicitly agree that IDEX is "the answer", bit it's "an option".
the mmu 2 & ercf seem over complicated ... and complication leads to poor reliability. i cant help but feel re-purposing the 4 stepper motors involved here into 4 bowden extrudes with a 4 to 1 mixer would simplify things immensely.
You just described the original MMU...
The MMU2S filament sensor has to be the worse designed sensor I have ever worked with. I literally have difficulty manually triggering it during testing. If they just used a different sensor I think my unit would actually be somewhat reliable. As it is now the MMU2S is useless.
If you can't manually trigger it, it likely needs to be aligned, alignment of the FINDA is critical.
@@LA3DPrinterRepair thanks, but I went ahead and sold my MMU2S and got a Bambu X1C with AMS. It is 10x more reliable than the MMU2S, but I still have had some issues with the poop shoot clogging on that machine.
Your pointer stick is triggered by voice… very annoying. Please use it to point to items and not move by voice…