Machining, Measurement, and Control Laboratory

Prediction of Machining Accuracy of 5-Axis Machine Tools with Kinematic Errors
M. Sharif Uddin, S. Ibaraki, A. Matsubara, T. Matsushita

Kinematic errors due to geometric inaccuracies in 5-axis machine tools cause deviations in tool positions and orientation from commanded values, which consequently affect geometric accuracy of the machined surface. The present research work studies the prediction of machining accuracy of a 5-axis machine tool with its kinematic errors. First, kinematic errors associated with linear and rotary axes of a 5-axis machine tool with tilting rotary table type, are identified by a DBB method. By using an error model of the machine tool, erroneous tool position and orientations are computed. Then, machining error with respect to the nomial geometry is predicted and evaluated. In an aim to improve geometric accuracy of the machined surface, an error compensation for tool position and orientation is also presented. As an example, the machining of a tilted taper cone by using a straight end mill, as described in the standard NAS979, is considered in case studies to experimentally verify the prediction and the compensation of machining errors in 5-axis machining.