A COMPREHENSIVE TECHNIQUE FOR MEASURING THE 3-DIMENSIONAL POSITIONINGACCURACY OF A ROTATING OBJECT

A method for measuring the accuracy of rotating objects was studied. R otating axis errors are significant; such as the spindle error of a ma chine tool which results in increased surface roughness of machined wo rk pieces. Three capacitance-type displacement sensors were used to me asure the position of a rotating master ball. The sensors were mounted nr rite three orthogonal points on the spindle axis. The measurement data were analysed for rotating spindle accuracy, not only for the ave rage roundness error but also for the spindle volumetric positional er ror during rotation. This method is simple and economical for industri al field use for regular inspection of spindles using portable equipme nt. Tile time taken for measurement and analysis using this method is only about two hours. This method can also measure microscopic amplitu des in 3-D directions of vibrating objects.