conversor3mf

Print MakerWorld multicolor models on an Anycubic Kobra X without recoloring anything. Português · Español

Most multicolor 3MF files on MakerWorld are made for Bambu Lab printers. When you open one in Anycubic Slicer Next, the colors come in the file's filament order, not the order of the spools in your ACE. After syncing the ACE they end up swapped. Painted models are the worst case: the per-object color menu only shows one color, so you end up repainting by hand.

conversor3mf rewrites the project so that each color of the model goes to the ACE slot where that spool already is. It also includes an MCP server, so you can ask Claude to do it for you.

Not affiliated with Anycubic or Bambu Lab. All trademarks belong to their owners. Respect each model's license: the tool converts files you downloaded for your own use and never redistributes anything.

What it does

• Remaps colors. Rewrites per-triangle paint, the filament of each part and per-layer filament changes to your ACE slot order. It picks the closest color (CIEDE2000) and merges identical colors.

• Opens as a native Kobra X project. No "Printer parameter switching" dialog and no geometry-only import.

• Keeps the designer's choices. Layer height, walls, infill, supports, brim, ironing and fuzzy skin carry over. Speeds and temperatures come from the Kobra X system profile.

• Recenters plates. Objects on every plate are centered on the 260 mm Kobra X bed.

• Warns you. It flags colors with no similar spool, more colors than ACE slots, and PLA/PETG mixes.

• Recolors whole regions ("islands"). Turns all holly leaves green or all stars red, including the side walls of raised details, without touching the paint brush.

• Never overwrites anything. It writes <name>_KobraX.3mf next to the original.

Related MCP server: 3DP MCP Server

Requirements

• Windows with Anycubic Slicer Next installed. It is detected automatically; if not, set CONVERSOR3MF_SLICER to its folder.

• Python 3.10+.

• An Anycubic Kobra X with ACE. Other Anycubic printers may work but are untested; see Limitations.

Install

pip install conversor3mf

Use with Claude (MCP)

claude mcp add conversor3mf --scope user -- conversor3mf-mcp

If you use uv, you can skip the pip install step: claude mcp add conversor3mf --scope user -- uvx --from conversor3mf conversor3mf-mcp

Claude Desktop (chat app): open Settings → Developer → Edit Config and add the server to claude_desktop_config.json, then restart the app:

{
  "mcpServers": {
    "conversor3mf": { "command": "python", "args": ["-m", "conversor3mf.servidor_mcp"] }
  }
}

Then just ask, in any language:

"Convert C:\Downloads\coaster.3mf for my Kobra X"

"I swapped slot 4 for a yellow PLA"

"In the coaster, make the holly leaves green and the stars red"

Claude shows where each color will go before converting. When recoloring, it looks at a numbered map of the model.

First-time setup: tell it what is in your ACE

1. In Anycubic Slicer Next, select the Kobra X, sync the ACE and save any project.

2. Run this command, or ask Claude to "set up my ACE from that project":

   conversor3mf ace setup "C:\path\to\saved_project.3mf"

This saves the printer profile and your slot colors and materials. When you only change a spool's color, update it like this:

conversor3mf ace slot 4 --color "#FFD700" --type PLA

For a material that is not in any slot yet (ABS, TPU…), save a new project with it and run ace setup again.

Your data lives in %APPDATA%\conversor3mf. Change it with CONVERSOR3MF_DADOS.

Step by step: talking to Claude

Write in your own language, the way you'd ask a friend. These are the prompts that work best, in the order you'll usually need them.

1. First time: show Claude your ACE

Sync the ACE in Anycubic Slicer Next, save any project, then:

"Set up my ACE using the project C:\Users\me\Documents\any_project.3mf"

Claude reads the slots and lists them back. Check that colors and materials match the spools you actually have loaded.

2. Whenever you swap a spool

"I swapped slot 4 for a yellow PLA"

"What's in my ACE right now?"

For a material that isn't in any slot yet (ABS, TPU…), repeat step 1 with a project that uses it.

3. Converting a file

Always give the full path of the file, or the folder plus the file name:

"Convert C:\Downloads\coaster.3mf for my Kobra X"

Claude first shows which slot each color goes to and warns about problems. Then:

• If everything looks right: "go ahead".

• If a color has no similar spool, you can swap the spool and tell Claude ("I loaded a green PLA in slot 4"), or force a slot: "put the orange (filament 3) in slot 3".

• If the model has more colors than slots, tell it which ones to merge: "use the black slot for both the black and the dark gray".

4. Several files at once

"List the 3MF files in C:\Downloads and convert the ones made for Bambu printers"

5. Recoloring parts of a model ("islands")

Use the converted file (..._KobraX.3mf) and describe what and which color:

"In C:\Downloads\coaster_KobraX.3mf, make the holly leaves green and the stars red"

Claude draws a numbered map of every same-color region, picks the numbers and shows a preview of the result. Tips:

• Describe the part by shape, position or current color: "the small white stars", "the leaves around the border", "the red dots on the hat".

• For 3D figures, ask for another view: "look from the front" (or back, left, right, bottom).

• If numbers are crowded, ask it to zoom: "zoom into the top-left corner".

• Correct it with the numbers from the map: "not island 42, I meant 32".

• Nothing is overwritten: each repaint creates a new ..._repintado.3mf file.

6. Checking before you print

"Check C:\Downloads\coaster_KobraX.3mf in the slicer"

For projects with more than one plate, also open the file in Anycubic Slicer Next and take a look (see Limitations).

What Claude can't do: start a print, change settings inside the slicer, or download models from MakerWorld. Download the 3MF yourself, then ask.

Command line

conversor3mf plan    model.3mf                    # show which slot each color goes to
conversor3mf convert model.3mf --map 1=3          # convert; force filament 1 into slot 3
conversor3mf islands model_KobraX.3mf --view top  # numbered map of color regions
conversor3mf repaint model_KobraX.3mf 32=4,3=3    # recolor islands 32 and 3
conversor3mf verify  model_KobraX.3mf             # reopen in Anycubic Slicer Next and compare

Every command and option also works in Portuguese and Spanish, so use whichever feels natural. Help and error messages follow the language you type in, or your system language:

Force a language with --language en (or pt, es) or the CONVERSOR3MF_IDIOMA variable. Run conversor3mf --help for the full list.

How it works

• Color format. A Bambu/Orca 3MF stores filament numbers, not colors. The paint of each triangle is a hex-encoded subdivision tree with a filament number on every leaf. The converter decodes that tree, swaps the numbers and encodes it back. Every other part of the file is left untouched.

• Printer settings. They come from a project saved by your own Anycubic Slicer Next, so no Anycubic profiles are shipped with this package.

• Islands. Connected triangles of the same color, after welding duplicate vertices. When a triangle has several colors, recoloring only changes the leaves of that island's color, including on the island's border.

Limitations

• Verification of multi-plate projects. Anycubic Slicer Next 2.0.0.3 crashes from the command line on any project with more than one plate. Those projects are only checked internally, so open them in the slicer before slicing.

• Distance between plates in the slicer. Multi-plate projects are laid out side by side in the slicer, with a gap between plates. The bed itself is 260 × 260 mm; the distance from one plate to the next (314.4 mm sideways, 328.8 mm down) was measured from projects saved by Anycubic Slicer Next 2.0.0.3 for the Kobra X. Other printers fall back to 1.2 × the bed size, which is what Bambu Studio uses.

• More colors than slots. Similar colors get merged. For multi-plate projects you can print plate by plate and use --map.

• Mesh-only 3MF files. Files without a slicer project inside have no colors to convert.

Development

python -m venv .venv
.venv\Scripts\pip install -e .
.venv\Scripts\python -m unittest discover -s tests

The tests use synthetic 3MF files built in tests/fixtures.py and do not need the slicer. ferramentas/testar_na_interface.ps1 opens a file in the slicer GUI, takes a screenshot and closes it.

License

MIT