Filament buffer
Hi, I've got my MMU2s and mounted it today and it works fine, but I have problems with the filament buffer, the filament doesn't stop in the buffer but goes through
I have set it up almost identical to the print manual,
the only filament I have been given to "buffer" is prusament galaxy black, but the other more smooth filaments go through
I have only tried with prusament pla and prusa pla
Anyone else with the same problem?
Re: Filament buffer
I've just finally got around to assembling my MMU2S and upgrading the MK3 to a MK3S. I'm finding the buffer isn't collecting the filament on a filament change, it just pushes it back out to the filament drum. I think a custom buffer arrangement is going to be needed to suit my desk and shelf layout.
RE: Filament buffer
Hi, I've just finished my MK3 > MK3s and MMU2 > MMU2s upgrade and I have the same issue.
The filament buffer doesn't store the pushed back filament, instead it is pushed back straight to the rol of
filament, causing problems. I am testing it with Prusament PLA. I also think I need some kind of a custom buffer arrangement.
RE: Filament buffer
I haven't finished my assembly yet, but I've seen similar complaints. It appears to be related to how things are positioned from what I've seen.
Over in the User Mods sub-section I started a thread about using auto-rewind spools rather than the buffer since I have limited space for the spools and buffer.
RE: Filament buffer
mine works.. but my printer is on a cart with filament rolls under the printer. maybe add abit of tension on the "input" ptfe tubes with the screw?
I have a Prusa,therefore I research.
RE: Filament buffer
Yes, adding a bit of tension on the input ptfe tubes with the screw indeed solves the problem.
I made my first setup with as little friction as possible and with Prusament filament.....
Just too good, other less quality filaments worked perfect.....:) They just bent very easy...:):)
RE: Filament buffer
never do like 0 fiction...good fun to watch...but the rolls.. the poor rolls... that was before the buffer...I just have 5 rolls on a stainless steel shaft. but I did start off with mylar tubes on the stainless steel shaft.. bad idea... (memories....)
I have a Prusa,therefore I research.
RE: Filament buffer
Ahojte .
PTFE hadičky sa musia dotýkať zásobníka filamentu .
Buffer treba zložiť podľa návodu https://manual.prusa3d.com/Guide/7.+Spool+holder+and+buffer+assembly/1042
skrutky na PTFE hadičky dotiahnúť aby filament chodil volne !
Filament sa potom stočí v buffer .
🙂
RE: Filament buffer
Ahojte .
Je dôležité používať !
SAME PROBLEM: Filament buffer
Hi, I have the same problem,
but it is not solveable by thightening the screws. The filament most times goes straight through. Sometimes it is buffered. Is there an other solution?
thx for help - Carsten
RE: Filament buffer
So I did end up switching to the buffer, but I have not had the issue expressed here. Quite the opposite actually in that the entry and exit had far too much friction and caused problems.
I added this mod to the buffer and have been very happy with the result. Not only did it solve my friction issues, it also made the buffer much easier to load (both in moving all 5 to the same side and adding more space for your fingers).
The entry and exit paths are angled to direct the filament into the buffer, I don't know if it is more or less of an angle than the factory holes though. Might be worth a shot though.
RE: Filament buffer
I took my filament buffer out. Run directly into MMU from the spool because the drag caused by the buffer caused a lot of failed to load. Also the buffer made it difficult to remove and insert filaments. I don't even have PTFE tubes in the MMU. We see a lot of comment about making sure the filament slides through the whole printer path with little resistance and than we throw in a buffer and add a lot of resistance. We need a better solution.
RE: Filament buffer
Do you guys think that not using the buffer would actually cause the MMU to load and unload incorrectly? it just took me 24 hours to print an 8 hour print because i had to babysit it and take care of just about all the errors that are outlined in the MMU Handbook. i do not currently have the buffer installed. just didn't think it would actually cause lights to go off. thoughts?
RE: Filament buffer
I made some modified brackets to mount the buffer vertically, but I've also had good luck, at least with test multi-color prints, using loose coils of filament. Just be careful to avoid tangles.
RE: Filament buffer
@legacy3dprinting
Why do you not use the buffer? Do you enjoy babysitting your printer?
The stock PRUSA buffer works just fine for me no issues after hundreds of hours and filament changes.
With no buffer, depending on your spool locations several issues could happen. A filament can push back to the spool and "slip knot" under itself which can lock up the filament and cause the print to fail. It could also unwind outside of the spool side and then jam. Or it could tangle with an adjacent spool. The buffer was designed for a reason - to prevent these things from happening.
You can also investigate auto-rewind spool holders but they tend to be clunky, unreliable or increase the filament path friction, which can overheat the extruder motor, cause under-extrude or simply fail. Definitely stay away from any with a plastic spring - they generally fail to perform properly after a short amount of time.
You can also search for other buffer designs in case you are not using one because of filament path, shape or location issues.
RE: Filament buffer
@legacy3dprinting
You can also investigate auto-rewind spool holders but they tend to be clunky, unreliable or increase the filament path friction, which can overheat the extruder motor, cause under-extrude or simply fail. Definitely stay away from any with a plastic spring - they generally fail to perform properly after a short amount of time.
You can also search for other buffer designs in case you are not using one because of filament path, shape or location issues.
I concur with the above statements !
The problem with the current buffer is the difficulty of getting things loaded. Therefor I'm looking into solutions like
- https://www.thingiverse.com/thing:3895861
- https://www.prusaprinters.org/prints/32480-mmu2-slim-buffer
These will be much easier to load filament through.
I will have to make myself a version which will accept the bearings I already have though.
Having problems with bed adhesion every morning...
RE: Filament buffer
I printed a remixed buffer side piece (can't find the source right now) which allows it to 'swing' out conveniently. I then use two plastic pins to replace the screws and when I load the filament it's much easier to get it all the way through.
As you see, I also have the buffer mounted vertically behind the printer.
RE: Filament buffer
So I never did use the filament buffer. I went with the gravity auto-rewind spool. This kind of works, however sometimes it pulls the filament too far back out so it can't be picked up on the next turn.