Gear Generator
Generate gears that actually mesh. Set the module or diametral pitch, the tooth count, the pressure angle and the profile shift, and the tool draws a true involute tooth profile with root fillets and backlash, plus a bore with an optional keyway, D-flat or hex and lightening holes. Chain gears into a train, or build a rack and pinion or a planetary set with sun, planets and ring; everything turns at the right ratios while the tool reports the pitch, outside and root diameters, centre distance and contact ratio, and warns about undercut and the planetary assembly rule. Export a single gear or the whole layout at true scale as SVG or DXF for laser cutters, CNC routers, CAD and 3D printing.
Runs 100% in your browser — simulations are computed locally on your device.
Notes
- An involute tooth is traced by unwinding a taut string from the base circle; that shape keeps the speed ratio constant as the teeth roll, and lets the centre distance vary slightly without breaking the mesh.
- With the standard 20° pressure angle, gears below about 17 teeth undercut their own roots; a positive profile shift moves the cutter out and fixes it.
- A planetary set only assembles with evenly spaced planets when ring = sun + 2 × planet teeth and (sun + ring) is divisible by the number of planets.
- Runs 100% in your browser — simulations are computed locally on your device.
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