Enclosure Filament Y Junction V2

Original Prusa Enclosure Twin Spool Support

Filament guides and Y junction to support 2 spools in the Original Prusa Enclosure with custom side guides.

This is NOT an MMU mod, just a way to restore the double spool capability for easier color changes and to keep filament ready when necessary.

There should be a spare filament holder arm left after assembling the enclosure, now you'll need it (and now it has a place to live)

You'll need some PTFE tubing (ID 2.5 mm, OD 4mm is used in the enclosure and this is the suggested one for this mod too) and a quick connector to install this alongside with some M3 nuts and bolts (10 (or 12) and 6 (or 8) mm long ones).

You'll also need to move the humidity sensor, since the left side filament guide will go to it's place, however you can mount it pretty much in any corner later.

(!) The originally supplied PTFE tube from the right side filament guide is too long when the Y junction is installed. You can cut it to length (make sure, the extruder can freely move anywhere where it is supposed to), however this cannot be undone, please make sure you have replacement parts at hand in case you might want to revert to the original configuration.

I printed the parts following the Prusa part printing guide, but honestly, that might be a bit overkill for this. Use PETG or other material which can withstand the environment in your enclosure.

Assembly

Materials

(on top of the ones coming out from the disassembled filament guide).

• 4x M3x12 (or M3x10) bolt (6x total)
• 5x M3x8 (or M3x6) bolt (8x total)
• 9x M3 hex nut (14x total)
• 1x PTFE connector
• ~600-650mm OD 4mm, ID 2.5mm PTFE tube for the enclosure assembly
• ~500mm OD 4mm, ID 2.5mm PTFE tube for the link between the Y junction and the printer (might differ, depends on your setup and printer position, mine is on squash balls and the front posts were removed)
• 1-2 hygrometer(s) (optional)
• Optional Daybreak Neo Mini LED bar (+2 bolts to secure it + cables and controller)

Instructions

For V2.0 you can now use the alignment jig to help to determine the length of the PTFE tubes.

1. Remove the filament guide and the hygrometer from the enclosure (keep the screws and nuts, you'll need them for the new parts)
2. Print the parts you need (choose the left and right filament guide variety)
3. Screw in a PTFE connector into the nose of the Y Junction. Be sure that it is aligned correctly. (It is screwed in into the plastic for now, there is no heat insert version ATM)
4. Insert 2 nuts into the Y junction's main body for the assembly screws.
5. Assemble the Y junction's 2 sides, but leave the screws loose
6. Insert a piece of PTFE tube into one of the side holes and push it all the way in
7. Tighten the assembly screw on the side you are working with. (you can tighten both for extra assurance)
8. Place the Y junction onto the alignment jig using the the remaining screw holes (middle one and the one on the side of the PTFE tube). Please note that the version engraving is on the top side, that will face upwards
9. Place the “A” part (this is the front facing one) of the side guide onto the alignment jig next to the Y Junction
10. Route the PTFE tube through the groove and mark the length with a permanent marker (or be brave and cut it to length there, but this is not advised). Please note that there is an end stop in the “A” part, the tube should reach it when inserted into the part.
11. Cut the tube to length using your favorite PTFE cutting jig.
12. Repeat the PTFE sizing with the other side. The length of the tube is the same, regardless of the type of part you use on the side.
13. Assemble both side components and insert the PTFE tube
14. If everything went well, the whole assembly should fit on the top of the enclosure (above the door) and all the holes should be aligned (except the most center one, that is offset from the rest on the enclosure and it is not used in this component).
15. Validate the alignment by temporarily installing the Y Junction and checking the side guides for alignment.
16. Adjust as necessary
17. Once everything is aligned install the hygrometer (if you choose to have it) and install all components
18. Another piece of PTFE tube goes from the Y junction to extruder. It should be cut to a length which allows free movement of the extruder and does not stress the extruder or the Y junction during prints
19. Install it using the connectors on the extruder and Y junction
20. Install the second spool holder
21. Think a lot where did you put the second spool arm when you assembled the enclosure and removed it from the printer (or print a replacement), then install it
22. Insert filament on both sides until it reaches the Y junction
23. Push one of the filaments forward, it should enter the last tube and eventually the extruder
24. To change filament, unload the current one, pull it back onto the spool until it clears the nose of the Y junction and load the other one by advancing it manually until it reaches the extruder