Generate Gear Profiles Using FreeCAD Gear Workbench

This guide explains how to quickly design and generate accurate, parametric 2D and 3D gear profiles using the FreeCAD Gear workbench (FCGear). You will learn how to install the workbench through the FreeCAD Addon Manager, select from various gear types such as involute or bevel gears, configure critical mechanical parameters like module and tooth count, and prepare the generated model for 3D printing, machining, or integration into larger assemblies.

1. Install the Gear Workbench

If you do not already have the Gear workbench installed, you can add it directly through FreeCAD:

  1. Open FreeCAD and navigate to the top menu.
  2. Select Tools > Addon manager.
  3. Under the Workbenches tab, search for FCGear or Gear.
  4. Select the workbench and click Install.
  5. Once installation completes, restart FreeCAD to load the new tools.

2. Create a New Document and Select the Gear Type

  1. Create a new document by clicking File > New.
  2. In the workbench dropdown menu on the main toolbar, switch from your current workbench to Gear.
  3. The toolbar will display various gear generation tools. Click the icon for the gear type you need:
    • Involute Gear: Standard external spur or helical gear.
    • Internal Involute Gear: Ring gear used in planetary systems.
    • Bevel Gear: Conical gear for intersecting shafts.
    • Crown Gear: Cylindrical gear mating with a spur gear at a 90-degree angle.
    • Worm Gear: Helical screw profile designed to mesh with a worm wheel.

Clicking any of these icons instantly places a parametric gear object into your document with default dimensions.

3. Customize Gear Parameters

To tailor the gear to your specific mechanical requirements, adjust its values in the Property panel:

  1. In the Tree view (left sidebar), select the generated gear object.
  2. In the Property view below the tree, switch to the Data tab.
  3. Modify the primary parameters:
    • teeth (num_teeth): Set the total number of teeth.
    • module (module): Defines the size of the teeth (pitch diameter divided by the number of teeth). Both mating gears must share the same module.
    • pressure_angle: Typically set to 20 deg for modern standard gears, or 14.5 deg for older standards.
    • height: Sets the face width (extrusion thickness) of the gear. Set this to 0 if you only need a 2D profile sketch.
    • beta: Sets the helix angle. Leave at 0 deg for standard spur gears, or increase for helical gears.
    • clearance / head / dedendum: Fine-tune tooth depth and tip clearances if custom tolerances are required.

The 3D model automatically updates in the viewport as you change these parameters.

4. Integrate into a Part Design Workflow

To add center bores, keyways, or mounting holes to the generated gear:

  1. Switch to the Part Design workbench.
  2. Create a new Body.
  3. Drag and drop the gear object from the Tree view into the newly created Body (or use Part Design > Create a base feature with the gear selected).
  4. Select the flat front face of the gear, click Create sketch, and draw your center bore or shaft attachment profile.
  5. Use the Pocket tool to cut the hole through the gear thickness.

The gear is now fully modeled, parametrically linked, and ready for export to STEP or STL format.