MMU3 firmware compatibility

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The Original Prusa MMU3 is a direct successor to the Original Prusa MMU2S. The MMU3 unit brings significant hardware changes and includes brand-new firmware (version 3.0.0 or newer). This firmware is reverse-compatible, enabling its use with the MMU2S as well. Please review the provided information attentively, and if you have any doubts or questions, do not hesitate to reach out to our support team for assistance.

MMU firmware

The MMU3 utilizes new firmware for both the printer and the MMU unit. It's crucial to understand that beginning with MMU firmware 3.0.0, each release aligns with a specific printer firmware version. To prevent compatibility problems, when updating your printer, make sure to use the most recent firmware combination for both the printer and the MMU unit.

Supported MMU - Printer combinations

The list below describes a combination of a printer with either MMU3 or MMU2S unit running the firmware 3.0.0 or newer:

• Original Prusa MK3.9 / MK4
  • MMU3 unit - Fully compatible*. All the required parts are included in the MMU3 package.
  • MMU2S unit - Can be upgraded to MMU3 to be used with the printer.
• Original Prusa MK3S+
  • MMU3 unit - Fully compatible*. All the required parts are included in the MMU3 package.
  • MMU2S unit with firmware 3.0.0 and up - Compatible.
• Original Prusa MK3.5
  • MMU3 unit - TBA
  • MMU2S unit - TBA

• Original Prusa MK3S
  • MMU3 unit - This combination is possible, but the MMU3 package contains improved extruder parts designed for the MK3S+ extruder only, as there is a different adapter-printer-mmu part for MK3S and MK3S+. MK3S&MMU2S had a similarly-looking but different filament sensor assembly than MK3S+&MMU2S. When upgrading to the MMU3 chimney, a new extruder-idler-mmu part has to be printed.
    Additionally, note that the PTFE hotend tube supplied in the MMU3 package is only compatible with MK3S+ extruder.
    We recommend upgrading the printer to MK3S+ before attaching the MMU3 to it.
  • MMU2S unit with firmware 3.0.0 and up - Compatible.
• Original Prusa MK3
  • MMU3 unit -  Outdated extruder hardware (filament sensor and printed parts). The firmware is not optimized for this configuration. We recommend upgrading the printer to MK3S+ before attaching the MMU3 to it. 
  • MMU2S unit with firmware 3.0.0 and up - The firmware is not optimized for this configuration. We recommend upgrading the printer to MK3S+ before attaching the MMU2S to it.

• Original Prusa MK2.5S
  • MMU3 unit - This setup is under investigation by our developers. The main concern is different system voltage compared to the MK3S+ (12 vs. 24 V). The new MMU3 wiring harness is not compatible. The firmware is not optimized for this configuration.
  • MMU2S unit with firmware 3.0.0 and up - The main concern is different system voltage compared to the MK3S+ (12 vs. 24 V). The firmware is not optimized for this configuration.
• Original Prusa MK2.5
  • MMU3 unit - The new MMU3 wiring harness is not compatible. Also, the firmware is not optimized for this configuration.
  • MMU2S unit with firmware 3.0.0 and up - The firmware is not optimized for this configuration.

*This hardware setup was thoroughly tested and verified by our testing teams.

Share your custom setup

If you intend to create a custom setup or have optimized the firmware for any of the unsupported configurations, we encourage you to share your knowledge with our community.