modelSpiralizer

Small Python CLI tool to bend a strip-like STL into a flat Archimedean spiral around the Z axis.

This repository now also includes a static web app in web/ that runs fully in the browser and can be deployed on GitHub Pages.

Behavior

• Input strip is assumed to start near x=0 and extend in negative X.
• Spiral axis is Z.
• z values are preserved exactly (z_out = z_in for all vertices).
• inner-radius is the start radius at angle 0 (on +X).
• pitch is radial spacing per full turn (not helical rise).

Spiral law:

r(theta) = inner_radius + (pitch / (2*pi)) * theta

Install

python -m pip install -e .

Web app (local)

cd web
npm install
npm run dev

Then open the local URL shown by Vite, select one or more STL files, set inner radius (mm) and pitch per turn (mm), and click Spiralize.

• Supports ASCII and binary STL input.
• Auto-normalizes each mesh from its XY bounding box (aligns long side to X, moves the start to x=0, and centers the thin side at y=0).
• Choose winding direction: clockwise or counterclockwise.
• Concatenates selected STL files in order along X before spiralizing.
• Multiply repeats that concatenated part N times along X before spiralizing.
• Max edge length (mm) optionally subdivides faces before spiralizing so triangle edges are not longer than the chosen value (0 disables subdivision).
• Outputs a downloadable binary STL.

Run (your test case)

python -m spiralizer.cli --input lippe.stl --output lippe_spiral.stl --inner-radius 50 --pitch 5

Concatenate multiple strips first

Use --concat to append one or more additional STL strips after --input (joined in X so the next strip starts where the previous one ends).

python -m spiralizer.cli --input lippe_2m40.stl --concat lippe_2m40.stl lippe_2m40.stl --output lippe_2m40_x3_spiral.stl --inner-radius 100 --pitch 5

Notes

• STL has no guaranteed unit metadata; values are treated as millimeters by convention.
• If any part of the strip would cross the spiral axis, increase inner-radius.
• Best results assume each strip uses the same orientation (starts near max X and extends toward min X).

GitHub Pages deployment

1. Push this repository to GitHub and ensure the default branch is main.
2. In repository settings, enable GitHub Pages with source GitHub Actions.
3. The workflow at .github/workflows/pages.yml will build web/ and publish web/dist.