Laser triangulation-based thermal characterization of machine tool spindles according to ISO 230-3

To characterize the spindle displacement of a machine tool over time due to the heat generated by the spindle motor during operation, a measurement setup was developed consisting of five laser triangulation sensors arranged according to ISO 230-3. It is based on a modular, lightweight frame with features for quick disassembly for easier transportation and re-assembly with high repositioning accuracy enabling to run the test at different locations on different machines. To localize the laser spot on a rotating tungsten carbide bar, an on-machine laser beam origin and direction detection strategy for laser triangulation sensors was developed. The position of the bar was mapped in the three-dimensional space by a best-fit algorithm. The characterization of the thermal deformation of a machine tool at 15000 rpm over 1.7 hours showed robustness to the underlying laser origin and direction measurements and was demonstrated as suitable tool to analyze machine tool’s thermal compensation strategies. The most influential error contributors were identified and discussed.