Computer-controlled sinusoidal drive mechanism

We describe an inexpensive computer-controlled sinusoidal drive mechanism for dynamics carts (and other applications) with applications for resonance, normal-modes, and chaos experiments. The driver arm moves in a non-sinusoidal motion such that the cosine error inherent to its design corrects the motion, making the output a more nearly single-frequency wave than the output of commercially available drivers. In addition, the design facilitates easy access to the drive position at any point in time, allowing for the collection of phase information and synchronization of data to drive position.