A computer aided design system with parametric dimensioning : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Industrial Technology at Massey University

Abstract

This thesis develops the concept of a parametrically dimensioned CAD system. Conventional CAD systems require the actual dimensions of all objects drawn to be defined during the drawing process. To alter any dimension requires manual modification of all affected objects in the drawing. Parametrically dimensioned CAD systems would allow drawings to be constructed containing dimensions defined using variable parameters. These parametric drawings could then be fully specified at some later stage by supplying actual values for the parameters. Such systems would allow drawings of families of components (that varied only in their dimensions) to be easily produced from a single parametric drawing, would simplify dimensional modifications to drawings, and would permit the drawing production to be part of an automated design process.

The general requirements for such a parametric CAD system are developed in the thesis and the implementation of a limited package based on these ideas is described. On the basis of this work, it has been concluded that such systems are viable, could have successful user interfaces and would be a valuable extension to conventional CAD packages.