Gear Generator 3D Modeling Software

Type the module, the teeth and the bore, add a mate, and download each 3D Print STL File.

Module (mm)

Tooth size. Two gears only mesh if they share a module.

Teeth

Fewer than about 17 teeth undercuts at the root on a 20 degree gear, which weakens it.

Pressure angle

Two gears only mesh if they share this too.

Thickness (mm)

How thick the gear is printed.

Bore (mm)

The hole through the middle. 0 makes a solid gear.

Backlash (mm)

Play between meshing teeth, taken off both gears equally. A starting value to try, not a tested fit.

Mate teeth

Teeth on the partner gear. 0 makes one gear; any other number makes the pair at the right centre distance.

Hub diameter (mm)

A raised collar round the bore. 0 for none.

Hub height (mm)

Nothing is uploaded. Your file is read in your browser and never leaves your computer.

What this does

A stripped gear in a toy, printer or appliance is rarely sold on its own. Count its teeth, measure the outside diameter, and divide by teeth plus two for the module. Type those in, add the mate's tooth count, and the page draws both gears at the exact centre distance, turns them, and checks the tooth outlines never cross.

How it works

Type the numbersFill in the boxes above. Every one has a sensible starting value, so you can change one and leave the rest.
Read the resultThe table under the form updates as soon as you press the button, and shows how every number was reached.
Download the 3D Print STL FilePress the download button and drop the file straight into your slicer. It is written in millimetres.

About the formats

Backlash: The play between teeth. It is taken off both gears equally; start around 0.1 to 0.2 mm and adjust after a test print.
Matching settings: The mate is made with the same module and pressure angle as the first gear, the settings two gears need to mesh. The outlines are checked for overlap on screen; the printed fit is untested, and the undercut and overlap warnings still apply.

Questions

How do I find the module of the gear I am replacing?

Outside diameter in millimetres divided by the tooth count plus two. A 44 mm gear with 20 teeth is module 2.

Has this been print-tested?

Not by us yet. The geometry is built from the numbers you type and checked on screen, but no printed part has been fitted. Print one small test piece before a big job and adjust.

Is Gear Generator 3D Modeling Software free?

Yes. Every tool on StarForge is free, with no account, no sign-in and no limit on how many files you run through it. It runs on your own computer, so it costs us nothing to give away.

Is my file uploaded anywhere?

No. Nothing is uploaded. Your file is read in your browser and never leaves your computer. There is no upload step, no server copy and nothing kept afterwards, which is also why it works with the network switched off once the page has loaded.

How large a file can I use?

Up to 250 MB. The limit is your browser's memory rather than an upload size, because the file never goes anywhere; a file larger than that is refused with a message rather than crashing the tab.