CORRECTING METHOD FOR BALL SCREW PITCH ERROR

PROBLEM TO BE SOLVED: To provide a pitch error correcting method is capable of reducing which the labor for shortening the measuring time or calculating and inputting the correcting amount by reducing the number of positions to measure a pitch error and preventing the accuracy from being lower on the other hand by making the number of correct positions almost equal to or more than conventional one at least. SOLUTION: Concerning all the moving strokes of a ball screw, the error amount is measured for every distance interval of one lead and successively inputted to the storage part of measuring data of measuring interval positions, the error amount is measured for every position dividing the distance for one lead into a prescribed number for the desired fine unit length and successively inputted to the storage part of measuring data of divided measuring positions, these divided position error correcting amount data for one lead and respectively added to the respective error correcting amounts of measuring interval positions of all the moving strokes and stored and each time the moving amount reaches the said fine unit length at the time of numerical control moving of a moving object, the added and stored correcting amount is read out so that a command signal can be corrected.