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© Dr. Des. Volker Ruhl
Commercial Applications of Rapid Prototyping
Primary commercial applications are still in prototyping non-structural (e.g., plastics) parts for solid representation of a 3-dimensional solid design; fit, form and function testing, as well as for the fabrication of mold-making and investment-casting patterns. First functional parts were produced by one US manufacturer of orthopedic devices for one-of-a-kind implants using computed topographic scanning (see chapter “Digitizing”).
Main employers of the RP technology are the consumer product, aerospace, automotive and medical device industries, but the concept points in many different directions and to various other applications. With increased computational power and lower prices for hard- and software, automated fabrication has past the initial stage of widespread utilization. Because of their limitless possibilities for application, data- driven Solid Freeform Fabrication processes have the potential to become a dominant or key manufacturing technology in the future for making flexible, one-of-a-kind parts, offering an integrated approach to design, design development and implementation.
In its current state, the entire field of SFF technologies is characterized by dynamic development in two particular directions: first, the continuous improvement of currently commercially available systems, and second, the development and practical application of a number of new principles.
The Operational Steps
Most commercial RP&M systems worldwide and every researched system known to the author follow a sophisticated sequence of operational steps which is outlined beneath. Only recently some vendors introduced new “desktop apparatus’” which allow simple “push-button-printing”.
CAD Model - The basis of each SFF-process is a conceptual 3-D geometric model of the desired object. The geometric model has to be generated either on a surface-based modeling software, or preferably with a solid-based modeling software
Tessellation - The 3-D model’s boundary surfaces are approximated through tessellation, which means the geometry is simplified to a mesh of interconnected, planar triangles. The triangulated part surface is stored in a data structure called the STL format8, which originally stands for StereoLithography the additive process this format was developed for. The STL file-format consist of an unordered list of triangular facets without any
Rapid Prototyping - fit, form and function testing
Application of SFF master models for investment casting
A geometric 3D-solid model is the basis for each SFF process
Tesselation of the parts boundary surfaces
The mesh of interconected, planar triangles is stored in a data structure called STL - format
