International Journal of Precision Engineering and Manufacturing
In this paper, an optical-based method and system for measuring web thickness of microdrills considering runout compensation is introduced. The presented measuring method is a nondestructive and noncontact means based on the use of an optical micrometer (OM) and a surface scanning laser confocal displacement meter (LCDM). The OM is used to determine the runout amount and the cross-sectional outer diameter of the microdrill, and the surface scanning LCDM is used to scan the cross-sectional profile of the microdrill to further determine its dual cross-sectional flute depths with runout-related deviation amounts being excluded. Then, the cross-sectional web thickness of the microdrill is calculated through the difference between the determined cross-sectional outer diameter and dual cross-sectional flute depths. An optical-based measuring system, for implementing the presented method, was constructed. Experiments meant to measure web thickness of microdrill samples were conducted. It showed that the presented measuring method, combined with the constructed measuring system, was feasible for the runout compensation of the web thickness measurement for certain microdrills.