From FreeCAD Documentation
- Select the gear profile in the Tree view.
- Press the PartDesign AdditiveHelix button.
- Choose as Axis the normal of the gear profile, that is Normal sketch axis introduced in version 0.20. (In earlier versions the Base Z axis can be used as long as the profile's plane has not been altered.)
- Choose a Height-Turns mode.
- Set the DataHeight to the desired face width of the gear.
- To set the desired helical angle an Expression for the DataTurns is required.
- Click the blue icon at the right of the input field.
- Enter the following formula:
Height * tan(25°) / (InvoluteGear.NumberOfTeeth * InvoluteGear.Modules * pi)
, where 25°
is an example for the desired helical angle (also known as beta-value) and InvoluteGear
is the DataName of the profile.
- Click OK to close the formula editor.
- Click OK to close the task panel.