(Un)original Prusa Dry Box and MMU3 Buffer  

RE: (Un)original Prusa Dry Box and MMU3 Buffer

Hai Woody
That's nearly the same setup in my basement.

I replaced the big buffer with the auto spool rewinder:
https://www.printables.com/de/model/702217-mmu3-2s-5-spool-auto-rewinder-adapter-for-unorigin

You'll find also a coupler for the PTFE tubes (it's placed in the middle of the box - see picture on link). So you can use shorter tubes. But i'm not happy with that plastic PTFE connector. I'm waiting for metal PTFE connectors (see that small black piece on the Enclosure). I used that wall mount, doubled it so i can screw 5 PTFE connectors on each side.

I think no spool rewinder is a bad idea. On a color change, the MMU3 push the filament back to the spool (a little bit more than the length of the PTFE tube from the MMU3 <> Nextruder). So it's possible, that those filament fall down left or right from the spool. And on the next change to that color, you get a jam...

I also replaced the axis holder on top right (orange) with that one:
https://www.printables.com/de/model/575514-prusa-mk4-filament-guide-right-side-for-ptfe-m10-c

So i can use the spool holder (front/right) for special filaments. Just change the PTFE tube from the MMU3 to the connector on the right side.

Hope that helps 🙂

Greetings from switzerland
Mike

RE:

Thanks for your reply

Wow your set up is super elegant ! 

My plan would be to put the DryBox under the bench where my machine is locate. So do you think if i go with longer PTFE tubes plus the auto spool rewinder it should work ? I see that there is a hole inside the Drybox, under the spools, my plan would be to get out by there, going behind the Box all the way up direction the MMU3 

EDIT : Forgot to ask, with thoose auto rewinders. Are the spools easily changeable ? 

Greeting from France

Woody

RE: (Un)original Prusa Dry Box and MMU3 Buffer

Thanks 🙂

You can check that with your existing setup. Just replace the tube with a long tube (as long as you plan to use). If it works - it works :-). Take a good quality to reduce the friction as much as possible.

And yes, it's easy to change a spool with the rewinder. It has a long rod which points upwards. This can be used to conveniently pull everything upwards and then forwards (helps also when inserting it into the grooves). Definitly faster to change than with the original buffer.

Mike

RE: (Un)original Prusa Dry Box and MMU3 Buffer

Hi there,

I am in the process of building the heated version of the (un)original drybox, also to be used with MK4(soon to be S) and MMU3.

@Grisu How is your experience with the auto rewinder mod in general? What worries me with the design is that the slip, when the springs are fully loaded, is happening "uncontrolled" between the barrel and the spool. Isn't this prone to be affected by many things? For example

• roughness of the barrel
• material of the spool
• weight of the spool (full vs. close to empty)

The original rewinder design has a fixed connection between the barrel and the spool and an adjustable clutch allowing to control the slip.

Therefore, while still in the process of printing the frame, I am thinking about designing "classic" filament buffers to be added below the metal tubes on the bottom of the drybox. I think it might work space wise, but don't have any design yet. Anyone else tinkering with such an idea?

RE: (Un)original Prusa Dry Box and MMU3 Buffer

Sorry for my late answer...

The spool rewinder actually works without any problems.Only when I completely reload a filament (take the spool in my hand for this purpose and only then hang it in the box), I wind the spring by hand so that it has a certain basic tension.

I have not noticed any problems in connection with full or almost empty spools

Since it works for me so far, I haven't given it any further thought (and probably won't - too many other things I should/want to do 😀 )

RE: (Un)original Prusa Dry Box and MMU3 Buffer

@maximweb

Found today an interesting model:

https://www.printables.com/model/923474-anti-slip-sock-for-mmu3-2s-spool-auto-rewinder-ada

think that could be a good solution against slippering spools

RE: (Un)original Prusa Dry Box and MMU3 Buffer

Also tempted by this solution - seems to be the best one out there.

Although I'm sure I read with the Core One announcement that Prusa were looking at a filament storage solution to be used with the MMU3 and the Core One? I can't find where I got this information from though - and I'm second guessing myself as to whether I actually read it or not now!! lol