Questions for MMU3 Users
After a few months of happily printing with a new MK4S I am thinking of buying/assembling a MMU, but I have a few questions for existing users that haven't been answered looking at web pages and YouTube videos.
- All the pictures / videos show a small unit hanging from the top bar but there are no shots of where the spools of filament go. Does the kit include some standalone spools that sit somewhere near the printer? Do you have to buy addition pieces to hold the spools?
- I currently have the MK4S printer sitting in a repurposed Creality tent where it is pretty comfortable. There is a lot more room vertically than at the base (x-y). What is the footprint of a printer/mmu setup with 3-4 spools feeding it?
- I currently feed the filament from a SunLu dryer mounted on top of the printer. Is there any drying option for an MMU with multiple spools?
I guess my main concern is that if the combo takes up a lot of room I am going to have basically build a new home for the beast(?)
Thanks for your help
I got some of the answers from this video...
But I still would like to hear from actual users.
To be honest it sounds like a bit of a pain to set-up unless you leave the same 5 spools in place all the time.
RE: Questions for MMU3 Users
The MMU very much increases the footprint of the printer in its standard form. The MMU comes with 5 roller dispensers that the filament rolls sit on. The filament is run through PTFE tubes to a buffer which accounts for the slack when the MMU unloads a filament to load another. PTFE tubes then run from that buffer to the MMU itself and a further PTFE tube connects the MMU to the Nextruder. It's very simple and works well, or it did for me anyway, however, like I say it takes up a lot of space and the rollers are designed to be mounted next to the printer rather than above it.
Getting rid of the buffer saves a fair bit of space but you need to deal with the excess retracted filament which is where auto rewind dispensers come in. There are plenty of variations of the same theme which adds a counterweight to a centre hole mount dispenser. Personally, I had limited reliable success with the ones I tried which led me to go down the Filamentalist route which is a very well designed, practical and reliable system. Check out the thread Filamentalist autorewinder
As for using a dryer, if you're happy with the buffer you simply feed it from the dryer rather than using a roller mount.
RE: Questions for MMU3 Users
A further thought, one of the great side effects of the MMU is it doesn't load filament until it starts to print, meaning bed levelling is carried out with a clean nozzle so far less possibility of stray blobs or build plate dents.
RE: Questions for MMU3 Users
More details on MK4S and MMU3 than you probably want. The main problem I had is the spools and buffer are not in a dry environment. With all the hoopla about keeping spools dry, this could be a problem if you want to print filaments beyond PLA. The notes show a metal dry box that holds the spools and buffer. I am also converting to the Filamentalist no-buffer spool feeder/rewinder to help minimize drag in the filament feeding. Prusa provides a bare bones, reliable system. Then we all want to improve it.
Or... you can wait for the MMU4 . Is it days or a year away, no target date has been given. Just the note in the blog that Prusa is working on it and it will NOT be an upgrade, but a new purchase.
RE: Questions for MMU3 Users
Guess I don't have the real estate or the patience for MMU3 at the moment. We'll see what MMU4 brings I guess.
RE:
So if you get MMU3, use this buffer replacement and I use the Sunlu S4 right behind the printer, it is not a terrible footprint to be honest. Been working solid for me for quite a bit of printing. Also, the MMU3 has been pretty rock solid for me. I know others have had some issues but all my issues have been user error. I am only about a year into printing and have a very busy job so only lately have I been really cranking stuff out and it still has pretty much worked out of the box for me. I tried a lot of the rewinders and stuff and that is a road to frustration and fine tuning hell, but the buffer replacement with the dryer behind is simple and efficient and the footprint is only extended by the S4 which I would use anyway.
I also had a setup where I was feeding it from spools on hangars from a shelf above for a while and then the S4 on a shelf above for a while and both worked just fine. I added this since you mentioned you have more vertical space than horizontal
RE: Questions for MMU3 Users
For completeness, I ran across this Youtube describing a system for reducing the MMU footprint
Prusa MMU3 Upgrade - How to get a smaller footprint!!!
RE: Questions for MMU3 Users
Seems like a lot of work to do what the link I sent did in several hours printing. Not watched all of it yet but the buffer I linked with the S4 is working amazing and it also gives filament drying. Great vid and thanks for the link!