stephensmitchell-forks / rhino-gears

RhinoGears is a plugin for Rhino3D that can be used to generate custom gears.

RhinoGears

RhinoGears is a plugin for Rhinoceros that can be used to generate custom gears. This script is partially based on GearGen by Thomas Anagnostou. However, the original GearGen is incompatible with Rhino for Mac. RhinoGears is written in Python and is compatible with both Windows and Mac versions of Rhino 5.

Installation

Download the appropriate installer file from the Releases page, RhinoGears.rhi for Windows users or RhinoGears.macrhi for Mac users. Double-click to install the plugin automatically. Restart Rhinoceros to make sure the plugin is loaded.

Usage

After installation, the following commands will be available:

• InvoluteGear — Generate a gear curve with an involute gear tooth profile. Optionally also outputs the gear's pitch circle.

• Rack — Generate a rack curve for a rack and pinion system.

• BevelGearSrf — Generate a bevel (conical) gear surface with a specific cone angle. Optionally outputs the gear's pitch cone surface.

• HelicalGearSrf — Generate a helical gear surface with a specific helix angle. Optionally outputs the gear's pitch cylinder surface.

Important: There is a bug in Rhino (Win) where Python plugin commands don't get recognized immediately in some cases. If this happens, simply run the command EditPythonScript first to fix the issue. The bug is described here.

General hints

1. Gears that mesh correctly have the same module and the same pressure angle. In addition, their pitch circles should be tangential to one another.

2. The module of a gear determines its overall size. The diameter of a gear's pitch circle is equal to the module times the number of teeth.

3. The pressure angle determines the shape of the gear tooth. A higher pressure angle leads to stronger, noisier gear teeth. Standard values are 14.5, 20 and 25 degrees.