Abstract: The angular linear interpolation method is still applied as the default interpolation method for two rotation axes in the 5-axis milling, which causes an angle of deviation between the actual vector and the theoretical one. The circumference milling brings on an over/under cutting error, whose actual form of machining error lies on the type of machine. After analyzing, it’s found that the nonlinear error is completely made by angular linear interpolation method. Based on the study of the coordinate transforming method of 5-axis machines, and the angular linear interpolation method of the rotation axis & its non-linear error, is the plane interpolation algorithm of tool orientation developed, while the algorithm is reported and tested with the object of a machine with CA-axis swivel head. The result proved that it can resolve the problem of non-linear error.

Key words: 5-axis, Degree linear interpolation of rotary axis, Plane interpolation of tool orientation, Rotation tool centre point