|The present invention relates to a calibration method for calibrating the shafts of a machine tool, comprising the steps of: |
A. arranging a measuring gauge (6) with three linear displacement sensors (1) that are orthogonal to one another,
B. arranging at least one precision sphere (7),
C. establishing an estimated reference position of the center of the precision sphere (7) according to an estimated position of the shafts,
D. positioning the measuring gauge (6) over the precision sphere (7) according to the previously estimated reference position,
E. controlling the shafts based on the information of the linear displacement sensors (6.1) until they are located at the same distance from the center of the precision sphere (7),
F. recording the actual position of the shafts by means of the encoders (8),
G. comparing the actual position of the shafts with respect to their estimated position in order to determine the positioning error of the shafts.