Set the module and the number of teeth and the model rebuilds instantly. A pair is shown in mesh, with backlash for printing. The file is processed in your browser.

STL gear generator for 3D printing

A gear broke in a meat grinder, a printer or a toy, or you need a drive for your own mechanism — set the module and the number of teeth and the generator builds a single gear or a pair. The model rebuilds instantly and is processed in your browser. You get STL and 3MF.

Spur, helical and herringbone gears

• Straight (spur) — the simplest option.
• Helical — angled teeth (5–45°, 20° by default) for quieter running.
• Herringbone — two helical rings facing each other.

Pressure angle: 14.5°, 20° (standard) or 25°.

Module and number of teeth

Module from 0.3 to 10 mm, 6 to 200 teeth (up to 300 on the second gear of a pair). The pitch diameter (module × teeth), outside diameter and root diameter are shown under the settings. For a pair you also see the center distance and gear ratio: 20 and 40 teeth at module 1.5 give 45 mm between axes and a ratio of 2.

Matching an old gear

If you do not know the module, open “Match an old gear”, measure the outside diameter with a caliper and count the teeth. The generator calculates the module and offers the nearest standard one (ISO 54) with a single button. If the result is far from any standard, it warns you: the gear may have a profile shift or be imperial.

Few teeth — undercut

With few teeth the tooth root gets undercut and weaker. The generator warns you and suggests the profile shift to use; each gear of a pair has its own.

Shaft bore and hub

The bore can be round, D-shaped or hex, with a fit allowance (0.2 mm by default). The hub is set by diameter and height and gets an M3 set screw that presses on the shaft (on the flat, if there is one) and a nut slot from the top.

Printing

Backlash between teeth is 0.15 mm by default, with a 0.4 mm chamfer along the tooth edges. A pair can be viewed in mesh and spinning, so you see how the drive works.