Multi-axis CNC milling of a sculptured surface and post-processing for NC data

A new approach for multi-axis NC tool-path generation of sculptured surfaces is proposed. The new tool paths are a series of lines inclined at an angle to u-axis of a parametrical surface. From the Bezier surface model, the desired cutter position and orientation are derived by using modified Denavit-Hartenberg notation. A post-processor is developed in this paper to convert cutter location data to actual NC data. A simulation of the NC data for machining the Bezier surface is presented. For a given surface finish requirement, the magnitudes of rotational angle change of the two rotational axes are found to be small, and the number of cutter contact points is reduced for a sculptured surface machined with a ball-end cutter.