Thus, in practice, the points at which lift begins and ends mean that a tangent to the base circle appears on the profile.
A face cam that implements three outputs for a single rotational input is the stereo phonograph, where a relatively constant lead groove guides the stylus and tone arm unit, acting as either a rocker-type (tone arm) or linear (linear tracking turntable) follower, and the stylus alone acting as the follower for two orthogonal outputs to representing the audio signals.
In some applications, a single element, such as a gear, a barrel cam, or other rotating element with a flat face, may do duty as a face cam in addition to other purposes.
Face cams may provide repetitive motion with a groove that forms a closed curve, or may provide function generation with a stopped groove.
A once common, but now outdated, application of this type of cam was automatic machine tool programming cams.
Each tool movement or operation was controlled directly by one or more cams.