New machining test for identifying geometric and thermal errors of rotary axes for five-axis machine tools

Abstract

This paper presents a new machining test for identifying the geometric and thermal errors of rotary axes for a five-axis machine tool. A disc-shaped test piece containing 12 rectangular grooves is designed and processed. A coordinate-measuring machine is used to measure the rectangular grooves to identify four position-independent geometric errors (PIGEs) and six position-dependent geometric errors (PDGEs) of the rotary axis. On-machine measurements are performed under heating and cooling conditions to identify the six thermal errors. The identification principle and analytical solution of each geometric and thermal error are provided, and an uncertainty analysis is performed. Compared with two classical machining tests, the results of the proposed method are in good agreement; the agreement degrees of the PIGE, PDGE, and thermal error are 90.9%, 91.3%, and 85.1%, respectively. The identification principle and analytical solution of each error are simple and not affected by linear axes, thereby improving accuracy.