Abstract
When machining curved surfaces by an NC machine tool, there are two problems. One is that the feed rate cannot reach the specified value. The other is that the quality of machined surfaces is decreased by big acceleration and deceleration due to machine control. These problems are caused by that the method to generate cutter location data does not consider the sampling time of the NC controller of a machine tool. To solve these problems, approximation to cutter locations with series of circular arcs is proposed. Circular arc interpolation algorism is complicated and not rational. In this paper, two methods to generate NC programs are proposed. The first one is to make approximation paths of the cutter locations with circular arcs based on the locations of the center of curvature. The second one is to make the length between the start point and the end point of a circular arc equal to an integral multiple of the "specified feed rate F × sampling time T". The effectiveness of the proposed methods is confirmed by simulations and experiments.
