How to make 3D-printable gears that mesh
- Choose a gear type. Spur for simple parallel shafts, helical or herringbone for quieter running, bevel for a 90° turn, worm for a big reduction, rack for linear motion, planetary for a compact coaxial reduction.
- Set teeth and module. Pitch diameter = module × teeth. Gears only mesh with gears of the same module and pressure angle.
- Pick the shaft. Choose your motor or shaft under “Fits”, add a hub, and keep the M3 set screw so the gear can’t slip.
- Enter the mating gear’s teeth. The generator shows the centre distance for your shafts; for a bevel pair it also sets the cone angle.
- Make the mate. Swap the numbers (and the helix hand for helical gears) and generate the second gear.
- Download the STL and test the mesh with a quick print before building a loaded mechanism.
Recommended print settings
| Setting | Value |
|---|---|
| Material | PLA for prototypes, PETG or nylon for tougher parts |
| Layer height | 0.12–0.2 mm |
| Walls | 4 |
| Infill | 40% |
| Orientation | Flat on the gear face (worm: standing up) |
| Supports | None |
Frequently asked questions
What gear types can I generate?
Spur, helical, double-helical (herringbone), straight bevel, worm, rack, internal ring gears, complete planetary sets and GT2 2 mm timing pulleys.
Will two gears from this generator mesh?
Yes, if they share the same module and pressure angle. The teeth are true involutes, so place the shafts at the centre distance shown under the settings: module × (teeth 1 + teeth 2) ÷ 2. Helical and herringbone mates need the opposite helix hand; bevel mates need each other’s tooth count in “Mating gear teeth”.
What does module mean?
Module is the pitch diameter divided by the tooth count. Bigger module means bigger, stronger teeth. Gears only mesh with gears of the same module; 1–2 mm suits most printed mechanisms.
How do I make a worm and its wheel?
Generate the worm, then make a helical gear with the same module, the helix angle equal to the worm’s lead angle and the same hand. The lead angle and centre distance are shown under the settings.
Can the gear fit a stepper motor or a D-shaft?
Yes. Pick your motor under “Fits” (NEMA 17, NEMA 23, 28BYJ-48, TT and N20 gear motors are built in) or set the shaft type yourself: round, D, double-D, keyed, hex or spline. The fit clearance is added to the hole, and the set screw goes through the hub onto the flat, with a slot to drop the nut into.
How much backlash should I use?
The default 0.12 mm per gear suits a well-tuned printer. Increase it to 0.2–0.3 mm if the gears bind, and use at least 0.2 mm for a planetary set printed assembled.
Are these engineering-grade gears?
They are printable parametric models for prototypes, mechanisms and hobby projects. Bevel teeth use the standard back-cone approximation and worm wheels are helical gears. Check fit, material strength and load for any functional use.
What print settings should I use?
PLA for prototypes, PETG or nylon for tougher parts. Print flat on the gear face at 0.12–0.2 mm layers with 4 walls and 40% infill. The worm prints standing up.