The automatically reciprocating Model RG linear drive eliminates complex controls and programming from simple spraying assemblies. Spray head travel speed and direction are mechanically controlled. No adjustments to the motor's speed or rotational direction are needed in order to change the travel direction or linear speed of the spray head. This means the system may be driven by an inexpensive, unidirectional motor. Fewer interruptions to adjust controls results in longer periods of continuous production which improves throughput rates. Spray guns, including extension arms and other tools, may be attached directly to the load-bearing drive head - a separate load carrier is usually not needed. Dirt and debris will not collect on the smooth, threadless shaft.