A Better 5-Wheel Filament Buffer

This is an improvement on the excellent 5-Wheel Buffer for MMU2 design. The most significant improvements:

• Uses M10 PTFE tube quick fit connectors that prevent the tubes from sliding out.
• Narrower fit between wheel and arms, preventing filament from getting stuck.
• Extra screw hole for the stem that holds the ball bearing/wheel.
• Mounting holes, (like someone else did, too).
• Can be printed as single unit (i.e., one filament) or combined.

This can be used with the original wheel from the 5-Wheel Buffer for MMU2 design (which is included in the Files section) or using the improved wheel (also included in the Files section) though I did not test that.

For the full 5-filament setup, print (without supports):

• 1x Combined Base
• 5x Verticals
• 5x Wheel (either the original or the improved version)

In additional, you will need:

• 20x M3 x 10mm screws
• 10x PC4-M10 PTFE tube holders
• 5x 608 ball bearings, one for each wheel
• A good length of 3mm ID x 4mm OD PTFE tubing
• One or more PTFE tube separators

Obviously, for the single-filament setup, you need to print the 1x Individual Base and reduce the other prints accordingly.

You should use the improved MMU2S passthrough adapter, and connect the output of this buffer straight into the MMU2S. No “open” filament should exist between this buffer and the MMU2S. Phrased differently, there should only be PTFE tubing between the buffer and the MMU2S.

You need to prevent the PTFE tubes from being pulled into the MMU2S too far. One way to do it is to put some tape around the tube where it meets the MMU2S. (A photo is included.)

Finally, please take note of the following:

• You need to keep these 3 ends of PTFE tubes as short as possible:
  • The part at the top, where the filament feeds in from the spool
  • The other end of that PTFE tube, that protrudes towards the wheel
  • The PTFE tube end that hovers over the wheel
• Keeping these short prevents the filament from bending sideways and getting caught on the wrong side of the wheels.
• You may need to clear the screw holes from any filament remnants.
• If you find you cannot fully screw in the M3 10mm screw to tighten the wheel between the vertical bars, you may need to drill (!) open the screw holes in the stem that holds the ball bearing/wheel.
• Take a look at the photo: make sure to wrap the filament twice around the wheel.
• I wrote up some learnings to make the MMU2S work smoothly.
• I recommend you use this in combination with my wall-mounted filament spool holders.

Narrower fit to prevent filament from getting stuck, added M10 PTFE tube quick fit connectors, added mounting holes.