Involute Gear Generator

Module is the size of each tooth: pitch diameter divided by the number of teeth, in millimetres. A bigger module means bigger, stronger teeth. The only hard rule is that two gears must share the same module (and pressure angle) to mesh. Common laser and 3D-print modules are 1 to 3mm. Pick the module first, then the teeth set the diameter.

Give both gears the same module and the same pressure angle. The gear ratio is just teeth1 to teeth2. The distance between their centers is (teeth1 + teeth2) times the module, divided by two. So a 24-tooth and a 12-tooth gear at module 2 sit (24+12) x 2 / 2 = 36mm apart, center to center, and turn at a 2 to 1 ratio.

It is the angle of the tooth flank, and it controls how the teeth roll against each other. 20 degrees is the modern standard and works for almost everything. 14.5 degrees is an older standard, still used in some legacy gear trains and good for very small pinions because it undercuts less. As long as both gears match, either works.

With a 20 degree pressure angle, gears below about 17 teeth start to undercut at the root, which weakens the tooth slightly. They still cut and mesh fine for hobby use. For tiny pinions, either switch to 14.5 degrees or accept the small undercut. The tool warns you when this happens.

Yes. The SVG and DXF are written in real millimetres with the correct extents, so they import at the exact size in LightBurn, the Glowforge app, xTool, Fusion 360, or your slicer. The blue dashed pitch circle in the preview is a guide only and is removed from the exported file, so you only cut the gear and the bore.

It is completely free with no login. The gear is generated in your browser with JavaScript and nothing is uploaded. Download the SVG or DXF and load it straight into your software. Always cut a test gear on scrap to check the fit before committing.