A clutch mechanism for coupling and decoupling a motor to a rack is disclosed herein. The clutch mechanism having: a clutch lever pivotally mounted to an axis for movement from a first position to a second position; a cam gear having a cam surface, wherein rotational movement of the cam gear causes the cam surface to move the clutch lever from the first position to the second position; and a gear train configured to cause linear movement of the rack in response to rotational movement of the motor, wherein movement of the clutch lever from the first position to the second position disconnects a pair of gears of the gear train.