The Initial Graphic Exchange Specification (IGES) for design data and the EIA standard M and G Codes for Numerically Controlled machines (N/C) is used to develop an automated interface between existing computer aided design systems and N/C manufacturing systems. The Flexible Manufacturing Protocol, developed at the University of Maryland, outlines such an interface to control automated manufacturing cells used for prototyping quick design changes. This paper demonstrates one application of the protocol, developing an automated IGES to CNC interface to control a 3 axis CNC machining center given the geometric representation of the part in IGES format. Wireframe representations of 2-1/2 dimensional parts, composed of linear elements, are the primary tools used for design representation. The automated production of the sample part, presented in this paper, demonstrates that rapid prototyping is possible using an IGES design data file as input to the protocol.