RhinoAssembly

RhinoAssembly, the first Driving Dimensions plug-in for Rhinoceros, is a powerful tool for assembly design and kinematic simulation with capabilities of mainstream mechanical CAD packages. With RhinoAssembly you can easily position your rigid 3D parts with respect to each other by specifying assembly constraints (fixation, concentricity, coincidence, parallelism, perpendicularity, tangency, rigid sets) and driving dimensions (distance and angle) between their faces and edges. 


http://drivingdimensions.com/Rhino/