Abstract: Post-processing is the key of the transformation from CL-Data of CAM system to NC
program. Since the improper selection of rotation angle will leads to collision between cutter tool and
work piece and dramatic change of rotary axis in adjacent cutter-location as well as rotary angle
changes rapidly and non-linear error exceeds allowable limits in singular area. This paper proposed a
method which integrates optimization of rotation angle and singular handling in five-axis
post-processing. A post-processor was developed with C++ program language based on the method,
which inputs the CL-Data of CATIA NC manufacturing module and outputs the NC program. The
validity of the method is verified through Vericut simulation.

Key words: five-axis NC manufacturing, post-processing, optimization of rotation angle, singular area
handling