In this paper we present a new method for tool-path generation and adaptive interpolation for a three-axis CNC milling machine. This method satisfied the force and / or the error conditions by using a variable-direction variable-feedrate strategy based on Maximum Feedrate Map. The proposed adaptive interpolator modifies the cutting path and the moving direction according to the actual instantaneous position error in real time. It also adaptively slows down the speed of the cutting tool if the position error exceeds a permissible threshold so as to decrease the error. As the cutting points on the spline at each cycle are not calculated beforehand, memory requirement for the interpolator drastically reduces. The significance of the proposed method on the reduction of the cutting error in the presence of disturbance is demonstrated via computer simulations.