gitwtfhub

wtf is prusa-mmu-t-remap?

menelaus-it/prusa-mmu-t-remap — explained in plain English

Analysis updated 2026-05-18

0PythonAudience · generalComplexity · 2/5

TL;DR

A Python tool with a simple window that fixes Prusa 3D printer files so each filament color loads from the correct physical slot in the MMU unit.

Mindmap

mindmap
  root((repo))
    What it does
      Remaps T commands
      Fixes color order
      Edits gcode files
    Tech stack
      Python
      Tkinter
    Use cases
      Multi color prints
      Fix stalled color change
      Slicer automation
    Audience
      3D printing hobbyists
      Prusa MMU owners
    Limitations
      No bgcode support
      No INDX or XL multitool

Code map

Detail Auto

An interactive map of this repo's files and how they connect — its source is parsed live in your browser. Click Visualize to build it.

filefunction / class

Why would anyone build with this?

REASON 1

Print multi color models where the filament colors must load in a specific order but the physical MMU slots are arranged differently.

REASON 2

Fix a print that stalls or changes to the wrong color because an unused MMU slot confuses the printer firmware.

REASON 3

Set up an automatic post processing step in PrusaSlicer so every exported print is corrected without extra manual steps.

What's in the stack?

PythonTkinter

How it stacks up

menelaus-it/prusa-mmu-t-remap0xallam/my-recipe0xhassaan/nn-from-scratch
Stars00
LanguagePythonPythonPython
Last pushed2022-11-22
MaintenanceDormant
Setup difficultymoderatemoderate
Complexity2/52/54/5
Audiencegeneralgeneraldeveloper

Figures from each repo's GitHub metadata at analysis time.

Wtf does this do

Prusa MMU T-Remap is a tool for people who use Prusa 3D printers with a Multi Material Unit (MMU2 or MMU3), the accessory that lets a printer swap between several spools of filament during a single print. Normally the order you set up filament colors in PrusaSlicer has to match the physical order the spools are loaded into the MMU cassettes, and if they do not match, the printer ends up loading the wrong color. This project rewrites the gcode file after slicing so that each color you picked in the slicer gets sent to the correct physical slot, without changing anything else in the file. The tool has a graphical interface built with Python's tkinter library. You load a gcode file, and for each color used in the print you tell the tool which physical slot it is actually loaded in. It then produces a corrected gcode file ready to send to the printer. It can also be set up as a post processing script inside PrusaSlicer, so the interface opens automatically each time you export a print. Beyond simple remapping, the tool fixes a few quirks in how the Prusa firmware handles the MMU. It can activate slots that are not actually used in a print so the firmware does not get confused, it can move the color used for the printed brim, and it will detect and warn if you try to reprocess a file that has already been remapped, since doing that twice would corrupt the color assignments. It works with plain gcode files exported from PrusaSlicer, but not yet with the newer compressed bgcode format, so users on recent PrusaSlicer versions may need to turn that option off first. The project was built by someone without a programming background, using Claude AI for the coding, in response to a feature that competing printer brands already offer. It has been tested on a Prusa MK4S with the standard 3 slot MMU3 and a modified 12 slot version, and the developer welcomes reports from people testing it on other Prusa printer models with an MMU.

Yoink these prompts

Prompt 1
Walk me through installing Python and the optional packages needed to run remap_gui.py on my computer.
Prompt 2
Help me set up this script as a PrusaSlicer post processing script on Windows.
Prompt 3
Explain how to fill in remap_physical.json for my specific MMU cassette color layout.
Prompt 4
I keep getting a disabled tool error on my Prusa printer, help me understand what filament used remapping does and why it fixes that.

Frequently asked questions

wtf is prusa-mmu-t-remap?

A Python tool with a simple window that fixes Prusa 3D printer files so each filament color loads from the correct physical slot in the MMU unit.

What language is prusa-mmu-t-remap written in?

Mainly Python. The stack also includes Python, Tkinter.

Who is prusa-mmu-t-remap for?

Mainly general.

View the repo → Decode another repo

This repo across BitVibe Labs

Don't trust strangers blindly. Verify against the repo.