A Machining Test to Evaluate Geometric Errors of Five-axis Machine Tools with its Application to Thermal Deformation Test

This paper proposes a machining test to calibrate position-dependent geometric errors, or “error map,” of rotary axes of a five-axis machine tool. At given sets of angular positions of rotary axes, a simple straight side-cutting using a straight end mill is performed. By measuring geometric errors of the machined test piece, position and orientation of rotary axis average lines (location errors), as well as position-dependent geometric errors of rotary axes, can be numerically identified based on the machine's kinematic model. Furthermore, by repeating the proposed machining test consequently, one can quantitatively observe how the position and the orientation of rotary axes change with respect to the tool spindle due to thermal deformation induced mainly by tool spindle rotation. Experimental demonstration is presented.