TECHNIQUE 42 Rapid Prototyping

There are three main ways to create a rapid prototype. Formative techniques use machines to make raw materials into the desired shape. Subtractive processes start with a large solid, then remove material to make the shape desired. Additive processes rely on layering material over and over until the part or product reaches its final position and shape. 

Rapid prototyping (see Technique 42) is often used as a precursor to prototyping. A rapid prototype is usually made of plastic and is not meant to be structurally sound. A prototype, on the other hand, should resemble the finished product, in materials and functionality, as much as possible. 

The competitiveness of materials is influenced to a considerable degree by how much time is required to produce prototypes rapid prototyping) and tooling techniques rapid tooling). The integration of rapid engineering with simultaneous engineering (CAD, CAE, CIM, TQM. ..) is now considered the state of the art. A further opportunity is presented by the continued intensive development of products suitable for inmold assembly techniques. 

Three-dimensional printing 3D printing or 3DP) is a rapid prototyping (RP) technique that was developed in 1992 at the Massachusetts Institute of Technology (MIT) [109]. In contrast to 3D plotting of hot polymer melts, 3DP uses CAD models that can be obtained with a personal computer [110]. 3DP is a layered fabrication process in which a layer of powder is spread onto the powder bed on which the model will be created. Then a print head ejects... 

Rapid Prototyping Model of Power Saw Cabinet Part as seen in Figures 6 and 7. Using the Stereolithography technique the part was modelled from a polymere. 

A prototype is a 3-D model suitable for use in the preliminary testing and evaluation of a product (also used for modeling a die, mold and other tool). It provides a means to evaluate the product s performances before going into production. The ideal situation is for the prototype to be the actual product made in production. However machining stock material and using rapid prototype techniques can make prototypes (Chapter 4, BOOK SHELVES). 

Harrison C, Cabral J, Stafford CM, Karim A, Amis EJ (2004) A rapid prototyping technique for the fabrication of solvent-resistant structures. J Micromech Microeng 14 153-158... 

Cyclohexyl phenyl ketone was used by Johnson et al. (3) to photocure intermediates for three-dimensional articles using rapid prototyping techniques. The product exhibited stable tensile properties over time. 

After the patterns on these polymer films are transferred into photoresist films coated on silicon substrates using photolithography, the developed photoresist patterns can serve as a master to make the required PDMS stamps. By combining this method of rapid prototyping with soft lithographic techniques, we can fabricate patterned microstructures of polymers and metals within 24 h of the time that the design is completed. Rapid prototyping makes it possible to produce substantial numbers of simple microstructures rapidly and inexpensively. 

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