Tool path design for cube-machining test to minimize influence of Z-axis reversal error motion

Abstract

Cube-machining test is a possible method for evaluating the accuracy of five-axis machining centers. Although the geometric errors of rotary axes can be evaluated by measuring the height and inclination errors of the machined surfaces, other error sources, such as tool length and profile errors, influence the machining accuracy. Clarifying the factors that influence the machined result is necessary to correctly evaluate the machine tool accuracy based on the cube-machining test results. In this study, the effect of tool path and Z-axis reversal error motion on the cube-machining test accuracy was investigated. Actual machining tests were conducted with three types of the reversal error conditions of Z-axis. The Z-axis reversal error directly affected the results owing to different Z-axis motions for each surface of the workpiece. Based on the investigation, for the machining, a tool path pattern, which can reduce the influence of the Z-axis reversal errors by restricting the motion direction changes of Z-axis for all surfaces, was proposed. According to the Z-axis reversal error test results, the surfaces machined using the proposed tool path were not affected by the reversal error.