Moiré fringes-based measurement of radial error motion of high-speed spindle

High-speed spindles (HSS) are widely employed in the fabrication of ultra-precision microstructures. However, the error motion of an HSS could seriously damage the produced microstructure. Therefore, measurement of radial error motion of HSS is vital. However, the measurement of the dynamic error motion of the spindle requires the utilization of a displacement sensor with a high sampling frequency. The sampling frequency of the applied displacement sensors cannot satisfy the requirement of measuring the dynamic error motion of an HSS. To overcome these limitations, the moiré fringes technology (MFT) is proposed to detect the dynamic radial error motion of an HSS. For that reason, an indicator grating and a ruler grating were used to measure the radial error motion of a spindle at speed of 6000 r/min. Our experimental results indicate that the improved MFT can successfully capture the radial error motion. The fluctuation of measurement results is less than 2% when the spindle speed increases from 600 to 6000 r/min, which corroborates the capability of the improved MFT to measure the dynamic radial error motion of the spindle at a higher speed.