Performance Analysis of the Vision Measuring Machine for Spindle Motor

The runout measuring machine for spindle motor in hard disk drive (HDD) using vision technology has been developed. The runout measuring machine performance analysis is necessary to prove the confidence of the measurement data. The measuring machine performance analysis is based on the measurement system specification measurement data and international measurement standards. This paper briefly describes the vision measuring machine and some system specifications definition, such as total indicated runout (TIR), the repeatable runout (RRO) and the non-repeatable runout (NRRO) and system resolution. This paper also describes the measurement system performance evaluation factors, for example, resolution, accuracy, repeatability and uncertainty. Further more, we analyze influence system measurement performance elements during measurement and system development procedure. This paper also introduces an effective measurement method to avoid worst accuracy component. The traceable calibration is set up to decrease measurement uncertainty which improves the system performance