Marbles · a Marbleworks run builder

Parts

Tap a socket in the scene, then Place.

Presets

Run

Marbles 6

Release interval 0.8 s

Speed 1.0×

Show the track centreline Shadows

Full accreditation The concept, the piece vocabulary and the dimensional reconstruction of the Discovery Toys Marbleworks parts are Codetaur's (@vibe-coded.com). They rebuilt the parts from reference photos with a parametric modeller and published the fitted numbers under MIT — the 47 mm rise, the 15 mm insertion, the 140.07 mm port span and the port table below all come from that work, used with attribution and unchanged. the post ngwnos/marbles the original notice + MIT text

What this bench adds, and what it gives up

Adds: it runs on a phone. The original is React + WebGPU/TSL, with Manifold generating the solids and a Box3D WebAssembly rigid-body solve. This is one static page: plain three.js from a CDN, no build step, procedural swept troughs, and a curvilinear solver — one arclength coordinate per marble, with the textbook rolling-sphere acceleration a = (5/7)·g·sinθ minus rolling resistance, free-falling 34 mm down each post between pieces.

Gives up: marble-on-marble contact, pieces that the marble can rattle sideways in, the storage tub, the cat's-eye refraction and the video export. A constrained marble cannot jam, cannot pass another, and cannot fly out of a trough it is going too fast for. Go to the original for those.

The grid everything is built on

Two pieces connect when a male post enters a female socket, which puts the upper piece exactly one rise higher. A marble leaves a trough 13 mm below where it entered, then drops 34 mm down the 21 mm bore into the piece below.

Touch: one finger orbits · two pinch and pan · tap a marker to aim, tap it again to place · long-press a piece to remove it, and everything it holds up. Mouse: drag to orbit · wheel to zoom · right-drag to pan · Q/E turn · Tab cycles markers · Enter places · right-click removes.
Teal rings hang a piece one rise below; violet rings stack one above — an outlet post feeds the piece under it, an inlet post feeds its trough.