Need Physics model for Hiller system Have been working on a model helicopter for some time and need to mathematically model a Hiller flybar. I have basic understanding of physics and have been researching gyroscopes to model the system, but still am missing a few bits and pieces. Have the Moments of Inertia figured out I think, but need to figure out the center of inertia for the system. Think that this will take the design above the principle axis. Can any one help or direct towards a detailed tutorial?