Abstract
This paper describes the measuring methods for positioning accuracy of tilting axis in five-axis controlled machining centers with a tilting rotary table. The top surface of the tilting rotary table is generally in higher position than the tilting axis. In this case, there is no measuring method except a manually operated clinometer. Thus, a clinometer consisting of a precision rotary encoder and a precision bubble level was firstly developed. In the method, operators have to read visually the scale of the level and the reading accuracy is dependent on their ability. Instead of the bubble level, an electronic inclinometer with high resolution was also developed. In addition, a ball-bar equipment was applied to the measurement of the angular positioning accuracy of a tilting rotary table. Since the ball bar equipment can measure the angular displacement continuously, the pitch error compensation will be accomplished precisely.
