Development of high-precision micro-roundness measuring machine using a high-sensitivity and compact multi-beam angle sensor

• A high accuracy micro roundness measuring machine (micro-RMM) for accurately measurement the roundness profiles has been proposed.
• The multi-beam angle sensor (MBAS) has been incorporated in order to improve the motion accuracy of the micro-RMM.
• The MBAS is less susceptible to instrumental errors for angle detection, can maintain high sensitivity with a miniaturized size.
• A measurement system for roundness measurement using the MBAS has been constructed. Experimental results confirm feasibility of the MBAS for roundness measurement are also presented.

With recent development in advanced manufacturing, demand for nanometric accuracy in dimensional metrology has increased dramatically. To satisfy these requirements, we propose a high-accuracy micro-roundness measuring machine (micro-RMM) using a multi-beam angle sensor (MBAS). The micro-RMM includes three main parts: the MBAS, a rotary unit, and a bearing system. The MBAS has been designed and established in order to improve motion accuracy of the micro-RMM. The dimensions of the MBAS are 125(L) mm × 130(W) mm × 90(H) mm. Compared with other methods, an MBAS is less susceptible to spindle error (stage-independence) when detecting angles, can maintain high sensitivity with miniaturized size, and can be used conveniently at the factory level. The optical probe, reported in this paper, is based on the principle of an autocollimator, and the stability is improved when using the MBAS. Unlike multi-probe methods, the micro-RMM is constructed to realize roundness measurement by using only one probe, which is less susceptible to instrumental errors. Experimental results confirming the feasibility of the multi-beam angle sensor for roundness measurement are also presented.