Abstract
When cutting freeform surface using NC machine tools, two problems occurred. The first arises because the actual feedrate deviates from the command feedrate. The second is the decreasing surface quality due to the large acceleration and deceleration of the control axes. The main cause is the fact that the toolpath of the NC program does not consider control characters .In this paper, an automatic identification method of a sampling time and a generation method of an NC program that considers sampling time are proposed. In addition, a system is proposed to estimate the machining time. The effectiveness of the proposed methods is confirmed by experiments.