Machining tests for identification of location errors on five-axis machine tools with a tilting head

Location errors are considered as one of the fundamental errors of five-axis machine tools. For the improvement of machine accuracy, it is important to propose an efficient and accurate identification method of location errors. This paper proposes an identification method of location errors on a five-axis machine tool with a tilting head by a set of machining patterns. The machining patterns are proposed under the assumption that the influence of motion errors of each axis on the measuring results is sufficiently small. Location errors of both linear and rotary axes can be decoupled and identified. During the measuring of linear axes squareness errors, a new machining method that significantly increases the moving distances of linear axes without additional removal of material or enlarged volume of the workpiece is proposed. Also, a decoupling method of linear and rotary axes squareness errors relevant to this new machining method is introduced. The measuring accuracy of linear axes squareness errors is greatly improved based on these measuring schemes. The machining tests are performed on a commercial five-axis machine tool with a tilting head. The measurement results are acquired on a coordinate measuring machine, and the identification results are validated by comparing the geometric characteristics of workpieces before and after compensation.