CAD model slicing and surface smoothing for building rapid prototyping parts

Development in computer aided design (CAD), finite element analysis (FEA), finite boundary methods (FBM) and geometric modelling have allowed for complex designs to be realized, minimizing redesign and analysis at early stages of product development life cycle. However, having a 3D prototype "part-in-hand" at the early stages of product development bridges the gap between design and manufacturing. This helps to realize abstract design features easily. Rapid prototyping has emerged as one of the forefront accepted means for producing "show-and-tell" and "touch-and-feel" models, that has gained the term desktop manufacturing, free form manufacturing etc. This paper looks into an important area of slicing CAD models, where a true representation of curves, surfaces can be generated from the approximated polygon representation in CAD models. Current rapid prototyping techniques have drawbacks due to "stair-case" effect. The technique described in this paper has drastically improved the quality of surface. A brief introduction to rapid prototyping principles, the concept of 'layer-by-layer' manufacturing, effect of curvature, algorithms for true curve representation, implementation and rapid prototype part finishing are discussed in this paper.