Direct Digital Manufacturing - New Product Development and Production Technology

Abstract

Direct Digital Manufacturing (DDM) also known as Rapid Prototyping or Rapid Manufacturing is a technology that converts three-dimensional computer models into physical parts typically by building layers upon layer of material. Although this technology has been serving designers for almost 20 years in support of demonstrating, testing, and confirming their designs early and frequently in the product development process, it is the future way for producing parts. Increasing interest of designers in DDM in the last decade has led to development of new technologies and advancements in DDM materials. Building a functional part or assembly directly from its CAD (Computer Aided Design) model gave ma- nufacturers the opportunity of rapid and custom production capability of parts such as molds, inserts, tools, sub-assemblies and even final products. It is unlikely that DDM will replace mass-manufacturing techniques in the near future due to some constraints. However, for small lot productions, highly complex parts and increased customization demands by customers - Direct Digital Manufacturing may be the answer. Today, more than thirty companies around the world manufacture DDM systems with different capacities and features. This paper is aimed to present background on DDM technologies, current ap- plication fields of DDM and comparison of DDM with CNC (Computer Numerical Control) technology . Background Direct Digital Manufacturing (DDM) is a fabrication technology that eliminates use of interme- diary processes. DDM parts are created directly from computer-aided design (CAD) models. Rapid manufacturing systems create parts from bottom-up, typically by building layers upon layer of material. The part is build by addition of layer-by-layer deposition (FDM), selective solidification of resin (SLA), selective sintering of metal, ceramic, or composites (SLS), and selective powder binding (3-dimensional printing). This layer-based manufacturing technique allows realization of complex geometries with high accuracy. The Rapid Prototyping (RP) technology has been serving manufacturers for almost 20 years in support of demonstrating, testing, and confirming their designs early and frequently in the product development process. Most likely, at the end of design iteration, a prototype is needed to provide feedback to design engineers. Using a prototype, a product can be better analyzed to identify errors and improve features. Feedback can also be received from prospective clients to aid the decision-making process. Increasing competition among manufacturers in global markets forced manufacturers to introduce new products more often and faster. Without a doubt, CNC based, handcrafted, or molded prototyping is not helpful enough in such business environment. Hence, interest of designers in RP has been increased during the last decade. CAD models can be realized within hours through RP systems. Large aviation and automotive