Abstract: Focusing on the complexity of the relative motion between cutter and workpiece in five-axis milling, a 3D trochoid mechanism is adopted to describe the actual tooth trajectory of the ball-end cutting edge. A kind of two-buffer mechanism is proposed to calculate residual height. One is established to determine each spatial buffer point which is discretized by a constant interval on workpiece surface, the other is built in cutter centre to simulate system dynamic response for each time interval. Thus, the nominal machined surface topography and system vibration trajectory can be calculated respectively. According to the exact time when cutting edge passing by the discretized point of the residual surface, the corresponding instantaneous vibration response can be interpolated and used to update the nominal residual height so that the prediction model of surface topography can be established with the consideration of milling system dynamic response. Validation tests are carried out with the varying cutting depth, increasing spindle speed, constant lead angle and fixed feed rate. It indicates that the proposed method can be used to predict surface topography accurately and distinguish stable milling status from chatter effectively.

Key words: 5-axis milling, Ball-end cutter, Dynamical response, Surface topography simulation