Thermal analysis of a novel five-axis machine tool using measuring probe and R-test procedure

Thermal errors have a significant impact on machine tool accuracy. Industrial experience shows that the thermal load on machine tools causes large displacements of the tool center point (TCP). In this paper, two methods are used with a 3D measurement probe to analyse thermal errors of a novel five-axis machining centre with rotary-swivel table and carbon-fibre reinforced Z-carriage: 1) Direct measurement of 3D TCP deviation at 4 defined ball positions. 2) Indirect measurement using R-test at a ball position with simultaneous 5-axis movement for the identification of geometric errors. For the thermal load on the machine, different heating strategies are used with defined movement of the axes and spindle. Four hours of heating and eight hours of cooling time are defined for each experiment. The results and the context of two measurement methods are presented and analysed for each heating and cooling strategy