On the base of analyzing the kinematics equations of non-circular machine tool, a new control algorithm is created by lathe tool kinematics principle, which based on the time-base method, in the non-circular machine tool have been verified on the experimental results show that the machining accuracy can be improved effectively. In order to obtain non-circular turning function relative to traditional CNC system, a new Open CNC systems was designed based on PMAC (programmable multi-axes controller) and linear motor. The research focused on the time-base following control between the CNC system and the linear servo systems used for the non-circular section turning. The advantages of the linear motor system directly driven by simple structure, quick transient response, high velocity and acceleration, high accuracy, little vibration and noise etc, which meets the requirements of manufacturing parts with non-circular section, and has been widely applied in the CNC forming and machining. To fit the crank non-circular contour, uses the high frequency linear servo motor to drive the tool move to-and-fro with high frequency, so the tool will track the crank non-circular contour with real time. With the results of several experiments for time-base following control with displacement feedback, the feasibility and efficiency of Open CNC system are verified.