Determination of the radial width of cut and cutting modes in milling

Abstract This paper describes a method to calculate the variation in the radial width of cut which occurs when the centre of a milling cutter follows the toolpath segments generated by a postprocessor. This variation is approximated by a stepped curve, thus enabling the toolpath segment to be divided into subsections, the radial width remaining constant over each subsection. The method also enables the cutting modes to be determined. The variation in the width of cut is obtained by performing a 2-D Boolean union between the area swept by the cutter when traversing the current segment and the area already machined. As an example, the actual widths of cut are calculated for the toolpaths for machining a pocket. The example clearly demonstrates that the actual widths of cut vary over a wide range and are very different from the value used to calculate the toolpaths. In fact, for the example considered, slotting occurs over 40% of the distance travelled, and only 10% of the actual widths of cut are approximately equal to the original value used for toolpath generation.