Analysis of the Effect of Open and Close Angle of Workpiece Surface on Contour Error

The machining of complicated surface is a hot spot in manufacturing industry in nowadays. The complicated surfaces should be machined with five-axis machine tools because of its geometric characteristics. In this paper, the characteristic of workpiece surface called open and close angle of surface is defined. The transition area from open angle to close angle will cause the twist and singularity of the surface. The twist mainly affects the principle errors of surface. And the singularity will cause the mutation of rotation axis movement and make an influence on the contour errors. To test the influence of the open and close angle on the contour error, a workpiece with special surface characteristics is designed. With the theoretical, simulational and experimental analyses, the influence law from the open and close angle is found out. The conclusion can be helpful for the tool trajectory planning.