Filament change on MK4 + MMU3

[@tomhorsley6566]

I just got mine built and setup a few days ago. I find it somewhat mesmerizing to watch the loops of filament grow and shrink in the buffer in sync with the filament going up and down the PTFE tube. I've even walked away from prints for a long time and it kept working without me watching it :-).

[@oleurgast730]

The reason the Prusa mk4 with MMU3 produces much less filament (and do the swap faster) is the nozzle. Bambulab (and Anycubic on the Kobra 3 combo) use higher flow nozzles. On standard-flow nozzles you can get a nice filament tip on unloading using ramping. Prusa did a good job developing theese. If using nozzles with higher flow, the filament-tip is not as good. You can not load it reliable again. So the "poo-makers" have to cut the filament inside the hotend, and poo out the filament left when loading the next. Imho the best way for filament changers would be using an hotend with changable nozzle. If you want multicolour - use a standard-nozzle with integrated heatbreak (Revo, Nextruder, TUN), to get fast filament change and low waste. If you want fast single colour prints - use high-flow nozzle. Cut&poo is o.k. if you only have a few filament swaps. Or maybe only print multicolour once a time. While toolchangers are the best way to do multicolour (and multimaterial), it cost quite a lot. Actually imho an IDEX plus filament changer would be the best balance between price and usefullness. For full multicolour use the filament changer (f.e. ERCF 2.0) on a hotend with standard flow. The second tool you could use with high-flow nozzle, to print the main colour fast. Or print TPU or soluble support.

[@PerMejdal]

I would love to have a well supported IDEX with MMU.

[@oleurgast730]

​@@PerMejdalThe big problem with IDEX is most manufacturers want to support duplex and mirror mode. But you can not compensate for bend or tilted bed by adjusting z (ABL) for two x/y coordinates at the same time. You also have to adjust the z-hight of the second extruder to be exactly the same as the first one, limiting the extruder design (and often increases the weight). Thats the main reason IDEX are a bit of a niche product - they are a hell to calibrate. However, the moment you say goodbye to duplex and mirror mode, most of the problems are gone. You can use ABL if only one extruder is active at a time. You can use different z-offsets on left and right extruder. You can use totaly different hotends left and right. However, marketingwise getting rid of duplex and mirror mode would be a problem. So I doubt we will see good, big Idex printers "ready2use" soon. The only IDEX as a kit wich might have more potential is RatRigs VCore 4 IDEX. Mechanical it could even compensate 2 z-offsets at the same time, as the bed can be tilted (I do not know if Klipper supports this or might support this in future). Also there are some interesting projects with magnetic IDEX. Magnetic IDEX uses only one kinematic for x/y to move. It ataches to the left or right tool, wich normaly docks on the left or right end of the x-axis. A quite interesting solution, its basicly a 2-tool automatic toolchanger. The best concept if you want to klipperize an old bedslinger and make it IDEX on the way... I actually think about converting my Anycubic Chiron to klipper. Extending the x-axis (a simple 2020 extrusion) on the way does not seem very complicated - and with theese nice CAN/USB toolbords using two instead of one also might be easy. However, I have too much projects going on to find the time... It's the "well suppoted" part being the problem... Imho at the moment Anycubic's ACE pro seems one of the most interesting solutions for filament changers. They have the "filament buffer" on the ACE, one for each filament, so the Kobra 3 has much less comunication going on between the printer and the ACE. Quite unlike the AMS. There are rumors the plan to make the ACE available for other printers. The moment they release the communication protocoll, it would be revolutionary...

[@AirtagAlex]

Thanks for sharing. How satisfied are you so far? Has it proven to be reliable?

[@PerMejdal]

100% reliable for now.

[@hanslain9729]

If your idle are bearings rattle check out the rattlefree idler on printables.

[@baddan]

Thanks for sharing I’m a owner of Prusa mk4 and curious about the new mmu3

[@PerMejdal]

It is very good. It even makes single color prints more reliable. Because there is not filament in the nozzle, while it is probing the bed.

[@1206549]

Hi. I really want an MK4 + MMU3 but almost pulled the trigger on a poop machine mainly because of cost but also because of another factor: Have you tried actual multi material? Like PETG with PLA support interfaces? I see people seem to be doing that on poop machines but I haven't seen someone do it with the MMU3. I've seen on the subreddit saying it can't actually do it. But I can't justify the waste on the poop machine if MMU3 can do it

[@PerMejdal]

Hi. I have not tried print with mixed martials on the MMU3. I don't see any reason for the MMU to be better or whose than the AMS for this task. If you really want to do mixed materials, you should get an IDEX or the Prusa XL. What I can say for sure, is that I am very satisfied with my MK4+MMU3 purchase. See more here: kzbin.info/www/bejne/kGOlpn-VbNmUnJY

[@jamesgates1074]

looks cool, I am waiting for mine to ship.

[@hanslain9729]

"poop machine" 😂

[@Dave_the_Dave]

For a 2d print like this or hue forge, the Bambulab doesn't create much waste either. The approach is not much different.

[@PerMejdal]

The filament changes on 2D is very few. So it make little difference there, that AMS spends 3 times the waste per change, compared to the MMU.

[@StereotypedFilms]

Seems very wasteful.. I like the toolhead changer much better.

[@PerMejdal]

For this model, what you see is all the waste there is. It was the last filament change. I made a comprehension of the waste on this model: makerworld.com/en/models/206936 The model is 49.07g. The table below shows the total amount of filament used, and the print time: Prusa XL: 58.08g 2h58m Prusa MK4+MMU3: 68.92g 4h54m Bambu X1C: 107.70 5h37m Bambu A1: 106.74g 6h04m