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Original Prusa MMU3

Original Prusa MMU3 support

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Original Prusa MMU3 support

Firmware & Downloads

PrusaSlicer 2.9.4

November 26, 2025

Handbook 1.03

June 05, 2025

Useful links

Firmware & Downloads
MMU3 Community Forum
MMU3 Printable Parts
Sample G-codes

Assemble the Original Prusa MMU3

Upgrade your MMU3 setup

Upgrade MMU3

Get started with MMU3

Multi-material slicing

Multi-material slicing

MMU3 regular maintenance

MMU3 regular maintenance

Regular maintenance is recommended for your Original Prusa MMU3 upgrade. Refer to the images below to familiarize yourself with the names of each part of the MMU3 unit. Idler…

Shipping information

Shipping information

Current lead time estimates for new orders Updated: December 10th, 2025 --> The dates are only an estimation at the date of update, specified above, and rely on…

Fix common issues

FINDA: Filament Stuck #04102 (MMU)

FINDA: Filament Stuck #04102 (MMU)

What happened? While the MMU unit was unloading a filament, the SuperFINDA sensor inside the selector stayed triggered/detecting a filament, while it shouldn’t. The superFINDA…

FINDA: Filament Stuck #04102 (MMU)

FINDA: Filament Stuck #04102 (MMU)

What happened? While the MMU unit was unloading a filament, the SuperFINDA sensor inside the selector stayed triggered/detecting a filament, while it shouldn’t. The superFINDA…

Community posts

MK4S/MMU3 How can I get into the Tool Mapping manually

1/12/2026, 9:20:18 AM
1 reply

MK4S/MMU3: false filament sensor triggers caused by PTFE routing / buffer geometry (repro + fix)

1/10/2026, 1:37:41 PM
1 reply

1/9/2026, 12:22:17 AM
7 replies

First thoughts on Filamentalist auto-rewinder

1/7/2026, 9:24:57 PM
40 replies

MMU3 on MK4S - Trouble Extruding

1/7/2026, 2:05:11 PM
12 replies

1. Introduction

2. MMU2S Disassembly (UPG)

3. MMU2S Buffer Disassembly (UPG)

4. Idler Body Assembly

5. Selector Assembly

6. Pulley Body Assembly

7. Spool holder Assembly

8A. Cassette Buffer Assembly

8B. CORE One Buffer Assembly

9A. MK4/S, MK3.9/S Nextruder mod

9B. MK3S+ / MK3.5 Extruder mod (KIT)

9C. MK3S+ Extruder (UPG)

9D. CORE One Nextruder mod

10A. MK4/S, MK3.9/S Setup and Calibration

10B. MK3S+ Setup and Calibration

10C. MK3.5 Setup and Calibration

10D. CORE One Setup and Calibration

11. First Flight

MMU3 Assembly (MK3S+, MK3.5, MK3.9/S, MK4/S, CORE)

18 chapters

Difficult

1. Introduction

2. Cassete Buffer Assembly

3. Spool Holder Assembly

4. Preparing the assembly

5. Preflight check

Original Prusa MK4S with MMU3 (assembled bundle) (1.0)

5 chapters

Moderate

1. MMU3 Assembled Core One Introduction

7. Spool holder Assembly

8B. CORE One Buffer Assembly

9D. CORE One Nextruder mod

10D. CORE One Setup and Calibration

11. First Flight

MMU3 for CORE One (Assembled)

6 chapters

Moderate

1. MMU3 Kit Core One Introduction

4. Idler Body Assembly

5. Selector Assembly

6. Pulley Body Assembly

7. Spool holder Assembly

8B. CORE One Buffer Assembly

9D. CORE One Nextruder mod

10D. CORE One Setup and Calibration

11. First Flight

MMU3 for CORE One (Kit) (1.0)

9 chapters

Moderate

1. Preparation

2. MMU3 Unit upgrade

3. Buffer upgrade

Original Prusa MK3S+ MMU3 to MK4/MK3.9 MMU3 upgrade (1.0)

3 chapters

Moderate

1. Conversion

10D. CORE One Setup and Calibration

11. First Flight

Original Prusa MK4S MMU3 to CORE One MMU3 Conversion (1.00)

3 chapters

Moderate

1. MMU Upgrade Intro

2. MMU2S Disassembly (UPG)

3. MMU2S Buffer Disassembly (UPG)

MMU2S to MMU3 Upgrade (MK3S+, MK3.5, MK3.9/S, MK4/S)

3 chapters

Moderate