Living Hinge Generator

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Read the writeup

Parametric lattice-hinge ("living hinge") SVG generator for laser cutting. Output is millimetre-true — 1 user unit = 1mm with a physical width/height — so it prints and cuts at real size.

All eight patterns at 50 × 200 mm. Click one to download the cut file. The pictures are display renderings — gold is the panel that stays, cream the slits the laser removes — with the stroke thickened and painted onto the panel. A real cut file draws a hairline on nothing at all, which a browser shows almost invisibly against a transparency checkerboard.

Built for LaserMadeMusic, so an instrument cut from flat sheet can have curved surfaces; the cutting and bending are shown there.

The rest of the build files — every instrument, generator and tool, indexed.

The operating guide — every option, the library API, and what each pattern is for.

Repository — the code, if you want to change a pattern or read how it works.

Download everything as a ZIP — the source, the guide, all eight examples and the coupons.

Quick start

cargo build --release                             # once; puts the programs in target/release/
target/release/living-hinge --list                          # patterns and their defaults
target/release/living-hinge -p wave -w 80 -l 300            # 80 × 300mm wave hinge
target/release/living-hinge -p chevron -w 80 -l 300 --margin 10   # with a 10mm margin
target/release/living-hinge --help                          # every option

Every pattern is committed cut-ready in examples/ at 50 × 200 mm, so you can cut one without running anything. Those are the files the guide's per-pattern figures describe.

Requires Rust (rustup). No dependencies beyond the standard library. The tools were JavaScript until 2026-11-02; the Rust port redraws every shipped file byte for byte.

Eight patterns

Pattern	Defaults (mm)
straight	pitch 3, bridge 2
dogbone	pitch 3, bridge 3, hole 0.5
wave	pitch 3, bridge 2, wavelength 13, amplitude 1, step 0.5
chevron	pitch 3, bridge 2, wavelength 13, amplitude 1
torsional	pitch 3.5, bridge 2, cap 1
honeycomb	side 5, gap 1.2
auxetic	cell 6.25, gap 1.5
crosshatch	cell 6.25, slit 4.5

Before you cut

Slits must reach the panel edges, or the hinge does not flex. That constraint wins over your other numbers: --side and --cell are fitted to the panel width, so they are targets rather than guarantees, and the report tells you what they became.

The stock is 3 mm Baltic birch plywood, and the defaults are aimed at it. The tuning numbers are still reasoned rather than tested, though: bridge width decides whether a hinge flexes or snaps, and the right value depends on your kerf as well as your stock. The coupons/ directory holds a bridge sweep for exactly that purpose — six otherwise identical 40 × 120 mm coupons varying only --bridge, so you can cut one sheet and find out.

Files

living-hinge.rs	the command-line program, built as target/release/living-hinge
src/generator.rs	the geometry library it calls
src/jsfmt.rs	writes numbers exactly as JavaScript did, so the files stay byte-identical
src/lib.rs · Cargo.toml · Cargo.lock	the Rust crate around them
living-hinge-guide.md · .html	operating guide; the markdown is the source
NOTES.md	how to reach this generator from a later session
preview.rs	draws previews/ from the cut files: the hairline thickened onto a gold panel
panel-convention.rs	draws the guide's panel-convention.svg from real generator output
examples/	one cut-ready file per pattern, all eight, at 50 × 200 mm
coupons/	bridge-sweep test coupons and cut instructions
index.html	this page, generated from README.md; GitHub Pages serves it
previews/	display renderings of every pattern — not cut files

Released under CC0 1.0.

Credits

Made by Michael Gernreich with Claude (Anthropic), working in Claude Code, which co-wrote the code and the documentation. Commits Claude made carry a Co-Authored-By: Claude line.