Abstract: A spray machine comprising a track and a carriage movably supported on the track carrying a cam actuator and a fluid spray gun. An air cylinder is mounted above the track having a piston slidably disposed therein with opposite piston ends coupled with the carriage. A pair of air lines are connected to opposite ends of the cylinder and to a source of compressed air through a valve controlling the flow of air delivered to the air cylinder. A valve actuator is mounted adjacent opposite ends of the track for activating the valve upon engagement with the cam actuator as the carriage approaches the track ends.