With state-of-the-art 3D measurement systems, short-wave structures such as tool marks cannot be resolved directly inside a machine tool chamber. Up to now, measurements had to be performed outside the machine tool. We present an interferometric sensor that carries out such measurements inside the machine tool, which saves time-consuming and expensive setup procedures. Our sensor HoloCut uses digital holography as measurement principle. By the use of multiple wavelengths, we get a large unambiguous axial measurement range of up to 2 mm and achieve micron repeatability, even in the presence of laser speckles. With a lateral resolution of 7 μm across the entire 20 x 20 mm2 field of view, both macro- and microstructures (such as tool marks) are measured with an axial resolution of 1 μm. Consequently, this qualifies HoloCut for in-situ measurements and integration in a machine tool. In this paper, the boundary conditions of integrating interferometers inside a machine tool are evaluated. Occurring vibrations and limited available space are particularly challenging constraints: The optical and mechanical design of HoloCut is introduced along with numerical correction algorithms: A piezo-stage setup is used to induce known displacements. Using these algorithms, measurements even with a closed-loop control of the machine tool head activated are demonstrated on a coin measurement. The use of HoloCut is motivated on the base of the daily operation of a 5-axis machine tool: We present an evaluation of an exemplary ISO 25178 parameter Sq using HoloCut measurements and compare those with reference, yet not inline-capable systems.
Fluid Jet Polishing (FJP) is a novel polishing technology, which experienced growing interest for niche applications over the recent years. This publication suggests FJP for processing of steel moulds for plastic injection moulding. These moulds are typically finished manually by skilled experts to date. FJP is capable of complementing the manual procedure or even replacing it. Fundamental knowledge about the process and its special tool function is provided. An experimental setup is demonstrated along with a polishing strategy and first results on different materials. It is shown, that it is possible to smoothen residual features from grinding, milling and turning below 0.12 mm. Furthermore an extract of current research is illustrated. Lastly a recently designed and built robot cell is presented, which is developed towards automation of the Fluid Jet Polishing process in the near future.