Parametric 3D modeling from the terminal that produces print-ready .3mf files for Bambu Studio and any 3MF slicer.

A .3mf is just a ZIP of plain-text geometry: a list of (x, y, z) vertices in millimeters and a list of triangles indexing them, plus the slicer's print settings riding along. This is a small, dependency-light Python library (b3d) for generating good triangles, validating that the result will actually print, and packing it into a .3mf you open directly in your slicer.

No CAD GUI, no STEP kernel, no cloud. Just code in, printable solid out.

All generated in code with b3d — organic hands via the signed-distance-field sculptor, the plaque via parametric solids + booleans.

• Primitives: box, rounded box, cylinder, cone, pyramid, tube, sphere, prism, torus
• 2D → 3D: extrude and revolve arbitrary profiles for custom cross-sections
• Boolean ops: union / difference / intersection (manifold-exact when manifold3d is installed, with a pure-Python BSP fallback)
• Text: emboss/deboss real font outlines onto a part, or generate standalone signs
• Validation: watertight / manifold / print-ready checks before you ever slice
• 3MF I/O: write from scratch, or swap new geometry into an existing .3mf while keeping its dialed-in print profile byte-for-byte
• Convert & inspect: .3mf ↔ .stl, unpack/repack for hand-editing, PNG previews

Requires Python 3.9+.

git clone https://github.com/wickdninja/bambu-labs.git
cd bambu-labs
pip3 install -r requirements.txt

numpy and Pillow are needed for rendering previews. manifold3d (robust booleans) and fontTools (text) are optional but recommended. Everything still works without the optionals, just with a slower boolean fallback and no text.

Write a short script — you're writing CAD, so write code:

import sys; sys.path.insert(0, "scripts")
from b3d import primitives as P, csg, threemf as T
body = P.box(60, 40, 12) # mm
holes = [P.cylinder(radius=2.5, height=20, segments=48) # M5 clearance
 .translated(x, y, -1) for x, y in [(-22,-13),(22,-13),(22,13),(-22,13)]]
plate = csg.difference(body, *holes) # drill 4 corners
assert plate.validate()["print_ready"] # gate before writing
T.write_simple(plate, "plate.3mf", printer="x1c", title="Mounting Plate")

Or use the CLI for one-shot operations:

python3 scripts/bambu3d.py make cylinder radius=10 height=25 -o cup.3mf --printer x1c
python3 scripts/bambu3d.py make rounded_box x=60 y=40 z=10 radius=5 -o case.3mf
python3 scripts/bambu3d.py text "HELLO" --size 15 --height 4 -o sign.3mf
python3 scripts/bambu3d.py inspect model.3mf # stats + health
python3 scripts/bambu3d.py render model.3mf out.png # preview without a slicer
python3 scripts/bambu3d.py validate model.stl # exit 0 if print-ready
python3 scripts/bambu3d.py swap template.3mf new.stl -o out.3mf --name Widget
python3 scripts/bambu3d.py stl model.3mf model.stl
python3 scripts/bambu3d.py unpack model.3mf ./dir # hand-edit, then `pack`

Pass printer= to center the model on the right bed. Known sizes:

mesh.validate() returns a report. The two fields that matter:

• ok — strictly manifold: watertight, consistent winding, outward normals, no degenerate faces. Primitives, extrudes, revolves, and manifold3d booleans hit this.
• print_ready — a closed solid with positive volume and no genuine gaps. Tolerates T-junctions that slicers auto-repair on import. This is the real bar for "will it slice." Never ship a file that fails this.

scripts/
 b3d/ the library: mesh, primitives, extrude, csg, text, threemf
 bambu3d.py CLI for routine one-shot operations
 selftest.py regression suite — run after editing the toolkit
references/
 3mf-format.md the 3MF/OPC format in depth
 bambu-container.md Bambu's specific files + the template-swap recipe
 toolkit-api.md full b3d API + a cookbook of real parametric parts
SKILL.md Claude Code skill manifest (see below)

Run the regression suite any time you change the library:

python3 scripts/selftest.py

This repo doubles as a Claude Code skill. Clone it into your skills directory (or symlink it) so Claude can drive the toolkit for you:

git clone https://github.com/wickdninja/bambu-labs.git ~/.claude/skills/bambu-labs

Then just ask Claude things like "model a ×ばつ40 mounting plate with four M5 holes and make it printable." SKILL.md is the manifest that tells Claude how to use the library.

• No exact curved-surface kernel (NURBS/STEP). Curves are tessellated; raise segments for smoother round parts at the cost of triangle count.
• 3D fillets (rounding top/bottom edges) aren't supported. Rounded vertical edges are (primitives.rounded_box).
• swap_into replaces the first mesh in a multi-object .3mf. For multi-body files, unpack and edit the specific object, or rebuild from scratch.
• Color/paint, supports, and multi-plate layouts are preserved on a template swap but not generated from scratch.

MIT. See LICENSE.

Not affiliated with or endorsed by Bambu Lab. "Bambu" and "Bambu Studio" are trademarks of their respective owner; this project just writes the open .3mf format their slicer reads.