Abstract: A jackscrew apparatus for converting reciprocal rotational motion into reciprocal linear motion includes a nut threaded on a screw for reciprocal translational motion and against rotational motion. A motor is connected to the screw and reversibly rotates the screw about a longitudinal screw axis to drive the nut through its reciprocal translational motion. A lost motion drive linkage is connected between the motor and the nut and allows lost rotational motion between the motor and the nut. The lost rotational motion allows the motor to accelerate before bearing the load of rotating the screw and driving the translational motion of the nut.