From master pattern to prototype via reverse engineering and rapid prototyping

It is known that reducing the time to produce prototypes is a key to speed up the development of new products. Today Rapid Prototyping (RP) systems play an important role concerning this duty. Irrespective of the applicated Rapid Prototyping techni- que, the first step of the entire process chain always has to the creation of a 3D CAD model of the desired geometry. Funda- mentally there are different ways to do so. The most common is to design a 3D CAD model on a CAD system. Master patterns with complex geometries are often fixed by machining and experimen- tal screening - and it's often impossible to describe these geometriesmathematically. The transformation of the geometry into CAD data is usually only possible with optical or tacti- cal scanning. The Fraunhofer-Institute for Applied Materials Research (IFAM) uses a non-contact scanning machine for this purpose, based on laser stripe triangulation technology. The direct link between the digitising and the Rapid Prototyping system ma kes it Possible to duplicate teh master pattern within hours. At the IFAM an application centre for the whole RP process chain has been established, consisting of a laser digitiser for data generation, FEM analysis, powerful CAD sys- tems for data modification and different RP systems like Stereolithography, Fused Deposition Modelling, Laser Sintering and Multiphase Jet Solidification for the production of proto- types. These RP techniques are described briefly in this article. Additionally an application of the interaction of Reverse Engineering and Rapid Prototyping for industry is given