One line in, a physics-true machine out

What it does

You type one line — “a turbofan jet engine, the kind that pushes a widebody off the runway” — and Claude researches the real machine, writes down its dimensions and physics, and emits a single self-contained HTML file: a three.js scene you can drag, explode, cut open, x-ray, and deliberately break. A bundled recorder script then turns the page into a 28-second film with a music bed, ready for your feed.

The interesting bit

The numbers on screen come from actual solvers — a Brayton cycle for the turbofan (~340 kN of thrust), chamber and nozzle equations for the rocket (2,462 kN, Isp 321 s), pump curves with affinity laws and NPSH for the process pump. Throw a fan blade and the solver computes the imbalance load the case must hold. The cutaway is also genuinely clever: no cap geometry, just shader-side plane clipping that draws section faces as freshly machined metal, so the cut can sweep live.

Key highlights

• One HTML file per machine, no build step, runs straight from disk in any browser
• Real proportions in metres with a scale bar; 15–40 named parts, thousands of solid pieces (twisted airfoils, involute gears, lathe-turned solids)
• Physically based materials — titanium, Inconel, copper — with heat glow driven by the solver’s computed temperatures
• Deterministic film clock (?film=1): time only moves when the recorder steps it, so takes are identical every run; the recorder even guards against the magenta frames a stalled headless GPU can produce
• Solver recipes for gas turbines, rockets, piston engines, watches, pumps, machine tools and more live in references/solvers.md

Caveats

• It’s a Claude Code skill, so an agent subscription is the intended path; the README does offer a no-agent fallback (fill the template by hand), but that’s clearly the long way round
• Recording films needs Node and ffmpeg on your machine
• Output quality depends on Claude’s research and four critic rounds — the skill sets a bar, but the agent still has to clear it

Verdict

Great for engineers, educators, and anyone who wants to actually see how a machine works — or wants scroll-stopping technical content. If you need validated engineering numbers rather than plausible, well-computed ones, treat it as a stunning visualization aid, not a certification tool.