@code3d/gears

Build complete nominal spur, helical and internal cylindrical gear solids from tooth dimensions and mounting parameters. Results are regular Code3D solids with named gear-axis and face references. assembleGears() positions compatible gear pairs and simple trains at their nominal shaft distances.

Installation

npm install @code3d/core @code3d/gears

The App includes Gears with its built-in Core. Install both packages when using Node or a project with its own Core installation.

Example

Build a spur gear with a keyed bore and a projecting hub.

import {spurGear} from '@code3d/gears';

export const wheel = spurGear({
  module: 2,
  teeth: 22,
  faceWidth: 10,
  mounting: {
    kind: 'bore',
    diameter: 8,
    keyway: {width: 2.4, depth: 1.2},
    hub: {diameter: 22, length: 6, side: 'up'},
  },
}).material('#d3b46c');

The gold wheel in the back row matches this example: 22 teeth, an 8 mm bore, a 2.4 mm keyway and a 22 mm hub. The gallery also includes a plain bore, an integral shaft, a helical gear and an internal ring.

Complete example: gears and mounting options.

Usage notes

• Dimensions are in millimetres and angles are in degrees.
• Results are solids with named axis and face references for placement.
• Geometry is intended for nominal layout and visualization. Flanks use sampled involute chords and simplified root transitions, not production tooth surfaces.
• A pair of generated gears is not a validated gear pair. Tolerances, load capacity and interference-free meshing require separate checks.
• assembleGears([first, second], {centerDistanceDelta: 0.2}) returns related gear values and chooses their tooth angle automatically. Use group(gears) to make one placeable assembly. Rotation follows the tooth-count ratio, including complete revolutions, and parts aligned to a gear frame follow that gear. The signed delta changes shaft distance; it does not specify backlash.
• Use assembleGears([input, [large, small], output]) for a compound shaft. The tuple's first gear receives the previous mesh; its second drives the next. The helper aligns their frames. Set layer spacing through the gears' origins, for example small.originOffset(0, -12, 0). Origin edits and uniform scaling preserve the gear metadata used by assembly.
• pairs[i].angle turns from the preceding center-line direction, in degrees. The default 0° continues straight. The first pair starts from +X; two 60° turns give center-line directions of 60° and 120° from +X. Negative angles turn the other way. The assembly example turns 60° at the middle gear, leaving a 120° included angle, then positions the whole train with a group(...).relate(...) constraint.

Complete examples: a three-gear train and a live two-stage transmission with coaxial large and small gears.

Documentation

• Gear API: constructors, dimensions, mounting and named references.
• Gear assembly: shaft distance, axial offset, array-order engagement, per-pair angles and fixed-axis transmission.
• Compound shafts: tuple entries, frame alignment and origin-defined layers.
• Standards and scope: nominal profiles, validation and modeling limits.

Source and development

• Public API: gear constructors and options.
• Tooth geometry: nominal tooth construction.
• Geometry tests: tooth dimensions, mounting and validation.
• Development guide: repository setup and test commands.