Optical measurement of micro cutting tools

Abstract

We present an optical measurement device for the complete 3D measurement of very small micro cutting tools with diameters down to 100μm and below. Such micro tools can be hardly measured by conventional devices such as tactile systems due to their complex geometry and small dimensions. The used optical device is based on the Focus-Variation principle which combines the small depth of focus of an optical system with vertical scanning to provide topographical and color information from the variation of focus. Full 360° measurements of the tools are automatically measured in a two step procedure. First, single measurements are performed from different directions all around the specimen with the aid of a motorized rotation unit. Then all single datasets are automatically aligned and merged to a full 360° dataset. Various measurement results are presented for milling cutters and drills including tools with diameters in the range of about 50μm. From the measured tools various parameters can be obtained including the major diameter, the core diameter or various angles. Additionally roughness measurements are provided on small cutting tools showing the versatility of the system for both form and roughness measurements. © Published under licence by IOP Publishing Ltd.