Abstract: The prediction of machining quality is an important sign, which can make virtual manufacturing actual utility. Having researched the formation mechanism of diameter dimension for turning, and simplified the dimension chain of process system, “three instantaneous centers” method is presented for predicting the precision of parts. After measuring and identifying the errors caused by kinematics and forced deformation of the actual process system, the visual predicting model is setup for virtual NC turning. The result of experiment is also given to show the effectiveness of the model. The research method can be applied to the predicting precision of other NC machine tools.

Key words: NC turning, Precision predicting, Virtual manufacturing, Virtual measuring