| • Backlash Feed is applied to the nut block, and the reading on the test indicator obtained when slight movement is applied is taken to be the reference. A load is then applied on the nut block from the same direction (table feed direction) from that state independent of the feed equipment, and the subsequent error between the return and reference after movement is canceled is taken to be the measurement value. This measurement is performed at each position at the center and at almost both ends of movement, and the largest of the obtained values is taken to be the measurement value. |