We present a system for animating an articulate figure using a physical skeleton, or armature, connected to a workstation. The skeleton is covered with sensors that monitor the orientations of the joints and send this information to the computer via custom-built hardware. The system is precise, fast, compact, and easy to use. It lets traditional stop-motion animators produce animation on a computer without requiring them to learn complex software. The working environment is very similar to the traditional environment but without the nuisances of lights, a camera, and delicate foam-latex skin. The resulting animation lacks the artifacts of stop-motion animation, the pops and jerkiness, and yet retains the intentional subtleties and hard stops that computer animation often lacks.