Advanced ultra-high precision system (NanoCyl) for accurate cylindricity measurements

Achieving ultra-high precision in manufacturing relies on accurate measurement systems, especially for geometries like cylindricity, which are fundamental components for precision engineering. However, current commercial cylindricity measuring machines struggle to provide the required ultra-high precision or comprehensive error analysis. This work develops an ultra-high precision cylindricity measuring machine (NanoCyl) for cylindricity profile extraction and accurate defect assessment with nanometre uncertainty. The NanoCyl incorporate the dissociated metrology structure and strict adherence to the Abbe principle, ensuring unparalleled accuracy by minimising external and internal disturbances. With in-situ calibration of capacitive probes and advanced data processing, the NanoCyl maintains traceability to the SI metre to ensure the high-precision performance. Error separation techniques (EST) are integrated into the NanoCyl to further eliminate the machine axis errors and optimise the measurement uncertainty. The NanoCyl can evaluate the three main components of cylindricity, as defined by ISO 12180–1: cross-section deviations through EST, median line deviations from harmonic signal analysis, and radial deviations using synchronised measurements from opposite probes. Experimental validation demonstrates the NanoCyl’s capability to achieve a standard measurement uncertainty within a few tens of nanometres. These findings highlight its potential for significantly improving the accuracy of cylindricity measurements, ensuring better quality control in high-precision manufacturing.