To buffer or not to buffer
I have ordered a MMU2S with filament buffer. Do I really need the buffer?
I have an enclosure in which the buffer does not fit in.
Re: To buffer or not to buffer
Up to you. It's meant to keep the filament from back-feeding onto the spool when it is unloaded, and then looping over the sides of it or tangling.
There are alternatives that mean you would not need it, e.g. if you were to print and use some auto-rewind spool holders from thingiverse that maintain some back tension to take up the MMU slack.
Re: To buffer or not to buffer
i would say for good prints you will need some kind of solution either as a buffer or auto rewind spool as already suggested.
The risk of tangling filament is just too big especially since anytime this happens it could ruin your print.
Re: To buffer or not to buffer
Hard decision. Without the buffer you have to handle the backfed filaments and ensure they do not tangle or jam when re-feeding. The buffer solves this effortlessly.
But is is not without its own issues, for instance feeding the filaments though a buffer and up to the MMU2 can be somewhere between tedious and downright difficult depending on your buffer design and location. I understand the Prusa buffer can be fiddly to feed the filament up to the MMU2 from itself as you can only move the filament an inch or two at a time. So a complete five spool filament change can become a major PITA and take some time.
My own design buffer is wall mounted and is a royal pain to change filament on, but I've not had a tangle since installing it.
But did you know that you cannot leave filament in the buffer for a few days if not in use? I tried it with PLA and after a few days the extended filament became brittle and was actually snapping under its own weight in the buffer. So it has to be unloaded and stored, meaning that every time you want to print with the MMU2 you have to reload again.
MMU2 is a clever concept and hopefully after the recent extruder and filament sensor update it will print more reliably. But it is by no means a switch on and forget appliance. It requires copious amounts of faffing to achieve results.
Hopefully that gives you some insights on life with a buffer! 🙂
Re: To buffer or not to buffer
You're going to need some sort of buffer. The buffer the come with it is good, but there are some real downsides to it. I find that it adds an unnecessary amount of friction to the system. The biggest issue is that it makes feeding filament in an absolute pain.
I think it is a very clever solution for making a buffer with a small footprint, but if you have the space there are better options
RE: To buffer or not to buffer
the extended filament became brittle and was actually snapping under its own weight in the buffer. So it has to be unloaded and stored, meaning that every time you want to print with the MMU2 you have to reload again.
I am having this problem and it is indeed a PITA. It means my printer is never "Ready" on Standby to print. Especially having to re-load the buffer.
With ample space and wall mounting can a buffer be avoided ?
RE: To buffer or not to buffer
Buffer is required. You can either use the PR default one or build your own version. I personally prefer the rewind solution. I don't like how the buffer is designed. Initial filament insert is just a pain.
Often linked posts:
Going small with MMU2
Real Multi Material
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RE: To buffer or not to buffer
But did you know that you cannot leave filament in the buffer for a few days if not in use? I tried it with PLA and after a few days the extended filament became brittle and was actually snapping under its own weight in the buffer. So it has to be unloaded and stored, meaning that every time you want to print with the MMU2 you have to reload again.
Have you run across any way to seal the Prusa buffer? I am thinking of using some shrink material, like the kind you use on windows and tighten up with a hair dryer.
I already added some extenders that allow for M10 passthrough Festos to be used with the buffer, so I am good there. I used these, VERY nice.