Computer-aided design prototyping

CAD (computer-aided design) prototyping uses kinematic and dynamic analytical methods to perform many of the same tests on a model. The inherent advantage of CAD prototyping is that it allows the engineer to fine-tune the design before a physical prototype is created. When the prototype is eventually fabricated, the designer is likely to have better information with which to actually create and test the prototype model. 

Figure 12.8-8. Using computer-aided design software and rapid prototyper to create product from a design blueprint.

Gaining from this technique requires skill with computer aided design (CAD) software, as well as the availability of a rapid prototyping machine (Exhibit 42.1). Therefore, you may need the help of someone who is versed and knowledgeable in this arena and its associated technologies. 

Stereolithography is a technique widely adopted in industry in conjunction with computer-aided design, CAD, and computer-aided manufacturing, CAM, i.e. micromachining [32, 37, 38]. Stereolithography allows the fabrication of solid, plastic, three-dimensional (3-D) prototypes or models of products and devices from CAD drawings in a matter of hours. Rapid prototyping by means of stereo-... 

Rapid prototyping (RP) or solid freeform fabrication (SFF) is a relatively recent approach to forming ceramic components. There are various forms of RP techniques, but they are based on a common principle a computer directly controls the shaping process by accessing computer-aided design (CAD) files. We can thus use RP to form a 3D component without the use of a die or a mold. RP techniques are used commercially for fabrication of parts from polymers for design verification and form-and-fit applications these techniques have more recently been applied to forming parts out of ceramics. 

Reverse Engineering (RE) is used to acquire the model geometry and shape when product drawings are not available and/or component details have been modified, typically for prototyping purposes. This approach is divided into an acquisition phase to obtain a measured point cloud, through the direct 3D digitizing of the object, and an elaboration phase to rebuild the Computer-Aided Design (CAD) and/or a Solid-to-Layer (STL) model. 

Fig. 7.5 Staircase effect left) Reprinted from International Journal of Machine Tools and Manufacture, Vol. 44, K. Thrimurthulu, Pulak M. Pandey, N. Venkata Reddy, Optimum part deposition orientation in fused deposition modelling, 585-594, Copyright (2004) with permission from Elsevier, and micrograph of 3D printed part with layer thickness of 0.25 mm (right) Reprinted from Computer-Aided Design, Vol. 34, R. I. Campbell, M. Martorelli, H.S. Lee, Siuface roughness visualisation for rapid prototyping models, 717-725, Copyright (2002) with permission from Elsevier...

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