Abstract: A rotary machine tool that includes first and second slides mounted on a bed for opposed movement transverse to the axis of rotation of a workpiece. Each of the first and second slides includes facility for mounting a cutting tool for engaging diametrically opposite sides of the workpiece from directions transverse to the workpiece axis of rotation. A control mechanism is coupled to the first slide for moving the first slide relative to the bed for controlled engagement of the cutting tool on the first slide with the workpiece. A hydraulic actuator is coupled to the second slide for moving the second slide relative to the bed in a direction transverse to the workpiece axis. A synchronizing valve is operatively coupled to the first slide for operating the actuator responsive to movement of the first slide so as to move the second slide by means of the actuator in a manner equal and opposite to movement of the first slide by the controller.