The shape of the machining surface of milling machine is generally composed of straight lines, arcs or other curves. Ordinary milling machine operators according to the requirements of drawings. Constantly change the relative position between the tool and the workpiece, and then cooperate with the selected milling cutter speed, so that the tool can cut the workpiece to process a variety of different shapes of workpieces.
CNC machine tool machining is to divide the movement coordinates of the tool and the workpiece into the smallest unit amount, that is, the minimum displacement amount. According to the requirements of the workpiece program, the numerical control system moves each coordinate by several minimum displacements, so as to realize the relative movement of the tool and the workpiece to complete the machining of the part.