Stepper motors: application and selection

A common denominator of most sophisticated manufacturing equipment is a positioning system. A part or workpiece must be brought into a predefined location envelope so that operations may be performed upon it. Since much of this type of manufacturing equipment is computer-controlled, flexible positioning systems are necessary to derive all of the advantages that the computer can provide. Flexibility can be achieved via closed-or open-loop motor-driven systems-each offering distinct advantages. But whereas stepper motors are optional in the former instance, for an open-loop system, a digital driving device such as a stepper motor must be used to maintain control.