Non-bar, an optical calibration system for five-axis CNC machine tools

Five-axis CNC machine tools comprise three linear axes and two rotary axes, enabling the fabrication of complex workpieces, such as dies, turbo blades, and cams. Improved measurement methods are continually being researched to increase the accuracy of five-axis CNC machine tools. This paper presents a novel optical calibration system, called non-bar, with no linkage bars. The system comprises a master detector module, a ball lens module, and a signal module. The proposed measurement system was implemented according to ISO/CD 10791-6 to measure A-type, B-type, and C-type five-axis CNC machine tools from three different manufacturers. The results demonstrate that the proposed non-bar measurement scheme provides high accuracy, high reproducibility, and simultaneous multi-axis measurement. ? 2012 Elsevier Ltd. All rights reserved.