A methodology for error characterization and quantification in rotary joints of multi-axis machine tools.

novel methodology was developed and implemented for error characterization, evaluation, and its quantification in a rotary joint of multi-axis machine tools by using a calibrated double ball bar (DBB) system as a working standard. This methodology greatly simplified the measurement setup and accelerated the error quantification. Moreover, the methodology is observed to be highly economical by reducing the tooling and instrumentation. However, considerable time and little more efforts are required in measuring and computing the errors. The developed methodology is capable of evaluating the five degrees of freedom (DOF) errors including two radial errors, one axial error, and two tilt errors out of six DOF error components of rotary joints. A DBB system with point accessory was used for direct measurement by change of length at multi-points and various locations, whereas mathematical modeling technique was implemented, and equation solvers were exercised for error evaluation and its quantification. Validation and authentication of the methodology and results obtained were carried out by simulation process prior to implementing the methodology on rotary joints of a five-axis turbine blade grinding machine. The results obtained from 'A' and 'B' rotary joints of the turbine blade grinding machine were presented by applying cubic spline technique for error modeling and its further utilization. The methodology was found extremely pragmatic, quite simple, efficient, and easy to use for error characterization and its quantification in rotary joints of multi-axis machine tools. [ABSTRACT FROM AUTHOR]