Adapting MMU3 to CORE One with Custom-Made Mount

Engelsk: Adapting MMU3 to CORE One with Custom-Made Mount

I’ve successfully integrated my Prusa MMU3 (Multi-Material Upgrade) with the PRUSA CORE One using a custom-designed, 3D-printed mount. The bracket is purpose-built: 250 mm long, with all necessary holes—including those for magnets and locknuts—ensuring a perfect fit without the need to drill into the CORE One frame.

Smart Design Detail

I discovered that there's an existing hole on the side of the CORE One frame where a PTFE tube fits perfectly—as if it was made for this exact purpose. I'm now using a 900 mm PTFE tube, and it works flawlessly without any modifications.

To ensure smooth filament movement, I used my own tool – the Tube Tools 60° In and Out Tool – to bevel both ends of the tube. This helps the filament feed and retract easily.

"PRUSA could consider making this hole round in future CORE One models and adding a rubber grommet—this would make MMU3 mounting even easier."

Mounting & Bracket Modifications

I reused the original MMU3 brackets but added two extra 3 mm holes to properly secure the MMU3 onto the mount—so it doesn't slide off. The mounting process only uses existing holes in the CORE One, so no permanent modifications are required.

The holder keeps the MMU3 stable and allows for clean, reliable filament routing via the PTFE tube. Where the frame has no mounting holes, magnets are used to hold the MMU3 in place—since it’s mounted on the right-hand side.

Important: Filament Sensor

You must NOT disable the side filament sensor in the CORE One menu.

To ensure it’s enabled:

Go to "Settings"

Select "Filament Sensors"

Make sure the Side Filament Sensor is enabled – this prevents issues with the filament FINDA in the MMU3

The slider should be pushed all the way to the right

Materials Used

1× PTFE tube, 900 mm

11× Magnets, 20×6×2 mm (from Prusa)

2× M3 screws, 10 mm

2× M3 screws, 14 mm

4× M3 locknuts

Links

MMU3 Conversion Kit with Magnets for CORE One https://www.prusa3d.com/product/original-prusa-mmu3-lite-for-core-one-conversion-kit/

MMU3 Printable Parts https://www.printables.com/model/531604-mmu3-printable-parts

Tube Tools 60° In and Out Tool https://www.printables.com/model/803340-tube-tools-60deg-in-and-out-tool

Best regards Leif Lumby Henriksen Odense3D Community: https://facebook.com/groups/2911561982402973

Dansk: Tilpasning af MMU3 til CORE One med specialdesignet holder

Jeg har integreret min Prusa MMU3 (Multi-Material Upgrade) med en PRUSA CORE One ved hjælp af en specialdesignet og 3D-printet vange til montering af MMU3-enheden. Vangen er designet fra bunden med en profil, der passer perfekt til CORE One-rammen – 250 mm lang og med alle nødvendige huller, inkl. til magneter og låsemøtrikker. Det betyder, at alt passer præcist uden behov for at bore i selve rammen.

Smart detalje

Jeg opdagede et eksisterende hul på siden af rammen, som passer perfekt til at føre PTFE-røret direkte ind – som om det var lavet til formålet. Jeg bruger nu et 900 mm langt PTFE-rør, som fungerer uden yderligere modifikationer.

For at sikre optimal filamentføring har jeg brugt mit eget værktøj – Tube Tools 60° In and Out Tool – til at skråslibe enderne på røret, så filamentet glider let igennem.

"PRUSA kunne med fordel lave det eksisterende hul i CORE One rundt og tilføje en gummibøsning – det ville gøre det endnu nemmere at installere MMU3."

Beslag og montering

De originale MMU3-beslag er genbrugt, men jeg har tilføjet to ekstra 3 mm huller i vangen, så MMU3’en kan fastgøres sikkert uden at glide af. Monteringen udnytter udelukkende de eksisterende monteringshuller i CORE One, så der er ingen permanente ændringer nødvendige.

Holderen sikrer en stabil montering af MMU3 og en ren, pålidelig filamentføring via PTFE-røret. Hvor der ikke er huller i rammen, bruges magneter til at fastholde MMU3’en – da den er monteret i højre side.

Vigtigt: Filament-sensor

Du må IKKE deaktivere side-filament-sensoren i CORE One-menuen.

Sådan kontrollerer du, at den er aktiveret:

Gå til "Settings"