Abstract: Reaction force transfer system includes a frame and a machine base supported by the frame through passive isolation structure. A carriage is supported for motion with respect to the machine base and a motor is provided having a stator coupled to the frame and a forcer coupled to the carriage to move the carriage with respect to the machine base.

Abstract: Spin stand platform having split axes. The platform includes an air bearing spindle stage supporting a test disk and constrained for motion in a plane on a surface along a first axis. A micropositioning stage air bearing is provided which is constrained for motion in the plane on the surface along a second axis orthogonal to the first axis and the micropositioning stage is adapted to support a read head element under test. First and second acuators move the stages to desired locations. At the desired location, apparatus removes air from the air bearings to lock-down the stages to the surface at the desired locations. It is preferred that the air bearings be vacuum preloaded and that linear motors be used to move the stages.