A motion control system comprising: a base; a stage supported by the base and movable with respect to the base; a motor (25;220) coupled to the base and operable to move the stage, the motor including: a mounting base arranged to connect the motor to the base; a friction pad engageable with the stage; a coupling portion (230;235) including a first end connected to the mounting base and a second end, the friction pad connected to the coupling portion between the first end and the second end; and a piezoelectric element disposed between the mounting base and the second end and operable in response to an electrical signal to move the friction pad and the stage; characterized in that the motion control system further comprises: a mounting screw accessible from an exterior of the base, the mounting screw engaging the coupling portion and being the sole attachment mechanism between the motor and the base, and a preload member including a motor end and an adjustment end, the motor end in contact with the motor and movable to apply a variable preload force to the motor, the adjustment end positioned to be accessible from the exterior of the base; and in that the motor has a star-shaped configuration with a first arm being connected to the mounting base at a fixed end, a second arm having a moving end attached to the piezoelectric element, and a third arm having a floating end where the preload is applied and which is used for preload adjustment. a base; a stage supported by the base and movable with respect to the base; a motor (25;220) coupled to the base and operable to move the stage, the motor including: a mounting base arranged to connect the motor to the base; a friction pad engageable with the stage; a coupling portion (230;235) including a first end connected to the mounting base and a second end, the friction pad connected to the coupling portion between the first end and the second end; and a piezoelectric element disposed between the mounting base and the second end and operable in response to an electrical signal to move the friction pad and the stage; characterized in that the motion control system further comprises: a mounting screw accessible from an exterior of the base, the mounting screw engaging the coupling portion and being the sole attachment mechanism between the motor and the base, and a preload member including a motor end and an adjustment end, the motor end in contact with the motor and movable to apply a variable preload force to the motor, the adjustment end positioned to be accessible from the exterior of the base; and in that the motor has a star-shaped configuration with a first arm being connected to the mounting base at a fixed end, a second arm having a moving end attached to the piezoelectric element, and a third arm having a floating end where the preload is applied and which is used for preload adjustment. a mounting base arranged to connect the motor to the base; a friction pad engageable with the stage; a coupling portion (230;235) including a first end connected to the mounting base and a second end, the friction pad connected to the coupling portion between the first end and the second end; and a piezoelectric element disposed between the mounting base and the second end and operable in response to an electrical signal to move the friction pad and the stage; characterized in that the motion control system further comprises: a mounting screw accessible from an exterior of the base, the mounting screw engaging the coupling portion and being the sole attachment mechanism between the motor and the base, and a preload member including a motor end and an adjustment end, the motor end in contact with the motor and movable to apply a variable preload force to the motor, the adjustment end positioned to be accessible from the exterior of the base; and in that the motor has a star-shaped configuration with a first arm being connected to the mounting base at a fixed end, a second arm having a moving end attached to the piezoelectric element, and a third arm having a floating end where the preload is applied and which is used for preload adjustment. a mounting screw accessible from an exterior of the base, the mounting screw engaging the coupling portion and being the sole attachment mechanism between the motor and the base, and a preload member including a motor end and an adjustment end, the motor end in contact with the motor and movable to apply a variable preload force to the motor, the adjustment end positioned to be accessible from the exterior of the base; and in that the motor has a star-shaped configuration with a first arm being connected to the mounting base at a fixed end, a second arm having a moving end attached to the piezoelectric element, and a third arm having a floating end where the preload is applied and which is used for preload adjustment.