Design and manufacture of free-form surfaces by cross-sectional approach

Conventional methods for manual design and analysis are not necessarily the best methods for computer implementation, lofting techniques, or computer aided design to produce a satisfactory result for the design of a wide range of shapes and the general form of the B-spline curve with the defining polygon adequately fulfils most essential requirements. Fourth-order curves seemed to be best suited for most cases, as they provide a compromise between smoothness and ‘localness’, yet curve orders of varying degrees still have some merit in certain circumstances.The most attractive feature realized with this method is the simplicity of design and the determination of the main input elements. Surface interpolation curves are shown and the production of a mould for a plastic handle indicated.