The sixth DOF is constrained by two hydrostatic slide bearings.
Motion is produced by servocontrolled electrohydraulic actuators.
At less than full load, the maximum accelerations are considerably greater. At low frequencies, the system is limited by displacements of 6 in. This unique feedback arrangement leads to excellent tracking between the table and the command signal. The frequency limit of the system is determined by the natural frequency of the table and of the supporting oil columns both of which have a natural frequency of approximately 60 Hz. This allows operations over a wide band of frequencies with small error.