# Teardown

Build an interactive 3D simulator of a real machine or mechanism (an engine, a landing...

- Repository: https://github.com/elvarofficial/teardown (886 stars)
- Category: Media
- License: MIT
- Last updated: 2026-10-31
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add elvarofficial/teardown --skill teardown -g -a claude-code -y`
Codex: `npx skills add elvarofficial/teardown --skill teardown -g -a codex -y`
Cursor: `npx skills add elvarofficial/teardown --skill teardown -g -a cursor -y`
Gemini CLI: `npx skills add elvarofficial/teardown --skill teardown -g -a gemini-cli -y`

## Description

Build an interactive 3D simulator of a real machine or mechanism (an engine, a landing gear, a walking linkage, a pump, a gearbox) as one offline HTML page people can take apart, with live panels driven by the same model that moves the parts, a button for every subsystem, cutaways, camera views and an auto tour that hands control to the visitor; then record it frame by frame to a 60 fps video with a synced procedural score. Use when someone asks how a machine works, wants a "visual explainer", a "simulator", a "cutaway", an "exploded view" or an "interactive 3D lesson", or wants a 3D object shown working rather than described.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Teardown

One machine, one page. The visitor sees the thing run, presses a button, and the part doing the work opens up while the gauges around it read the real numbers. Left alone, the page tours itself with a cursor. The same code records a film of the tour, frame by frame, with a score built on the same timeline.

`SKILL_DIR` below is the folder this file lives in. Builds and renders go to `./teardown-out` of the folder you run from.

## First run

```
cd "$SKILL_DIR" && npm install && npx playwright install chromium
```

The pages need nothing else. The video needs `ffmpeg` on PATH and the score needs Python 3 (standard library only). Set `FFMPEG`, `PYTHON` or `CHROMIUM` to point at other binaries.

## The 3 examples

Build one, open the HTML, press buttons. Copy the closest one when you start a new machine.

| | The machine | What drives it | Worth stealing |
|---|---|---|---|
| `v8-*` | A cross-plane V8 with glass liners: the charge burns inside the cylinder you track, valves lift on their cams, 8 pistons move from the exact slider-crank. | Crank angle. Firing order 1-8-4-3-6-5-7-2, a chamber pressure model for the indicator diagram. | Cutaway modes (glass, section, solid), the firing order as a cylinder picker, live charts synced to the crank. |
| `cessna-*` | The Cessna 337 main landing gear folding into the airframe on takeoff and dropping on landing. | Stroke 0..1: a 201 mm rack turns a 32-tooth pinion (module 4 mm) through exactly 180°. | One degree of freedom posing a whole mechanism, flight phases as functions of time, a runway that rolls under the model. |
| `strandbeest-*` | Theo Jansen's Strandbeest, 20 legs on one crankshaft, walking broadside over sand. | Wind. The crank speed is integrated from it; every joint follows by circle intersection from Jansen's 11 link lengths. | An exact linkage solver in 67 lines, instanced tubes, foot traces, a contact chart of all 20 feet. |

The rest: https://github.com/elvarofficial/teardown/blob/HEAD//SKILL.md