FreeCAD: How to make gear with Involute Gear tool

Update: May 22, 2021
FreeCAD 0.19
  1. Switch workbench to Part Design workbenchWorkbench_PartDesign.

  2. Select [Part Design]-[Involute gear...] menu.

    [Part Design]-[Involute gear...]
  3. Control panel for Involute gear will be displayed in Tasks tab. And a gear with the center (0, 0, 0) and the Z axis as the rotation axis is displayed on the 3D view.

    Editing an involute gear

    You can set following parameters in the control panel. After parameter settings, click OK to finish editing.

    ParameterMeaning of the parameter
    Number of teethNumber of gear's teeth
    ModuleThe value obtained by dividing the pitch circle diameter by the number of teeth. For example, if a gear has 30mm diameter and 20 teeth, you should set 1.5 (= 30/20) into this parameter. In general, the gears must have same module value to mesh each other.
    Pressure anglePressure angle. The angle between the radial line passing through the pitch point and the tangent line of the tooth profile.
    Heigh precisionIf True, heigh precision. Other, low precision.
    External gearIf True, external gear. Other, internal gear.
    Pitch circle
    Pressure angle

    Example of number of teeth

    Number of teeth: 26
    Number of teeth: 52

    Example of pressure angle

    Pressure angle: 10°
    Pressure angle: 20°
    Pressure angle: 30°

    Example of enable/disable heigh precision

    Heigh precision: True
    Heigh precision: False

    Example of enable/disable external gear

    External gear: True
    External gear: False
  4. Gear angle can be changed on Data tab. Select the created gear on model tree and edit rotational angle and axis on Data tab at bottom of Combo view.

    Direction parameters for gear
  5. Also gear position can be changed on the Data tab. Select the created gear on model tree and edit center position on Data tab at bottom of Combo view.

    Gear center position
  6. To make the gear 3D in Part Design workbench, the gear should be at inside of body. Create new bodyPartDesign_Body_Create_New, then Drag the gear on the model tree and place it under the body.

    Place the gear under created body
  7. Select the gear on model tree and extrudePartDesign_Pad it. If you want to create internal gear, do boolean operationPartDesign_Boolean with the extruded gear and another cylinder.

    External gear
    Internal gear