Conventional Coordinate Measuring Machines (CMMs) restrict the possibilities for measuring micro mechanical products and noncontact optical measuring methods are not suitable for true three-dimensional measurements. The integrated combination of optical sensors and mechanical transducers employed in this research makes an ideal low cost and high precision touch trigger probe possible to measure miniature components. This touch probe is composed of a stylus with a fiber sphere (310μm in diameter) and a sensor integrated floating plate. The ball tip is fabricated using optical fiber with melting and solidification processes. The stylus is attached to a floating plate, which is connected to the probe housing via four micro wires. The shape and dimension of the floating plate, as well as the length and diameter of the micro wire, are determined according to the selected contact forces. When the probe tip is displaced the wires will perform elastic deformation and four mirrors mounted onto the four-legged plate will amplify the up/down displacement at each mirror position. These displacements can be detected by four corresponding laser focus probes. Experiments were carried out to test the unidirectional touch trigger repeatability. The standard deviation is less than 10nm. The probe structure and the experimental results were also analyzed and validated with finite element AnSYS software.

Date Published: 31 December 2008
PDF: 6 pages
Proc. SPIE 7130, Fourth International Symposium on Precision Mechanical Measurements, 71300K (31 December 2008); doi: 10.1117/12.819556

Published in SPIE Proceedings Vol. 7130:
Fourth International Symposium on Precision Mechanical Measurements
Yetai Fei; Kuang-Chao Fan; Rongsheng Lu, Editor(s)