The main purpose of this study is to develop a measuring test device by parallel kinematics for measuring a motion accuracy of multiaxis machining centers. The initially developed measuring test device could measure only position of the spindle with three displacement sensors. With the 3DOF device the motion accuracy of machine tools with three-axis was measured. Since the mechanism of the joint was smooth and the sensor resolution was small enough, the measured result showed that the measuring device had an enough performance for the machining centers in normal accuracy. Then the 6DOF measuring test device was developed. It had six displacement sensors and it could measure both position and posture angle of the main spindle. Despite the adoption of parallel kinematics, forward kinematics calculation was possible due to the sophisticated arrangement of sensors, thus the hi-speed data acquisition could be possible.

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