There are two popular types of robot welding systems. The two are articulating and rectilinear. Articulating robot welding units employ arms and rotating joints. They move like a human arm with a rotating wrist at the end. This creates an irregularly shaped working zone. Rectilinear units move in line in any of three axes (X, Y, Z). In addition to linear movement of the unit along axes there is a wrist attached to allow rotational movement. This creates a working zone that is box shaped. There are many factors that need to be considered when setting up a robot welding facility. Provided appropriate maintenance procedures are adhered to, robot welding systems are able to operate continuously.