MMU3 CompactCore

I present to you the MMU3 CompactCore, my MMU3 solution that is economical in both space and material for the PRUSA CORE ONE

Design requirements :

• Economical

  • Less than 2 kg of material is required to print all components.

  • No bearings to purchase (only reuse the 5 bearings from the official MMU3 Lite kit and a few other parts).

  • A basic assortment of M3 screws and square M3 nuts is sufficient for assembly, nothing else
    (reuse of PTFE tubes and miscellaneous parts from the official MMU3 Lite kit).

• Keep the printer enclosure closed

  • Unlike the Lite kit, my solution retains the original enclosure.

  • Unlike the « blob » kit, there is no additional heated volume inside the enclosure for materials that require a temperature-controlled environment.

  • The MMU3 tube passes through a small gap at the rear right corner of the printer frame
    (slightly bending a corner of the metal panel is required to route the tube).

• Retains the ability to use the original side spooler without removing PTFE tubes

  • A Y split (tested through thousands of filament changes without any snagging on PLA, PETG, ABS (not tested with flexible TPU)) ensures both operating modes can be used without swapping PTFE tubes (do not forget to change the operating mode in the printer menu)

• Minimal space required behind the printer

  • Only 100 mm is required between the printer and the wall

• 100% printable on the Core One

  • No need for a larger printer to print the parts

• No modification of the MMU3

  • Only the original support and the MMU3 front plate need to be removed to adapt it to my solution

• Compact

  • Spools are placed directly on top of the printer on smooth, 100% printable rollers
    (based on the same principle as my custom spooler: https://www.printables.com/model/1377073-spool-holder-core-one-100-printable)

  • No more bulky buffers — they are mounted directly next to the spools

• MMU3 accessibility

  • The MMU3 remains accessible at the rear of the printer, as with official Prusa solutions.

• No autorewinder

  • I spent a long time considering this point… Auto-rewinders are attractive, but their reliability over long filament lengths led me to keep a buffer-based solution.

  • No friction adjustment, no spring issues, …

• Drilling as few holes as possible in the printer plexiglass

  • Only 2 additional Ø 3 mm holes are required.

  • Changed your mind later? No problem — these holes can easily be hidden using the original nylon rivets.

PLEASE :

• Carefully read the instructions (french or english) before starting the print and assembly

• Noticed something abnormal ? Leave me a message on Printables !

• Like my work? Feel free to like and comment !

Enjoy !