Practical experience of thermal testing with reference to ISO 230 Part 3

Abstract

Thermal errors in machine tools can represent up to 70% of the total positional accuracy of machine tools [l]. The significance of temperature-induced errors led to the introduction of an international standard method of testing for thermal effects [2]. A wide range of machme tools has been measured and assessed by the Ultra Precision Engineering Centre (UPEC) to advise on thermal error avoidance and to implement error correction where appropriate. This paper presents some results taken fiom these machines and discusses the implications for manufactured parts. Attention is also drawn to the problem of distinguishing from the various sources of thermal effects during tests that may take several hours in a variety of workshop conditions. The results suggest that some deviation from the standard can provide more process-specific information.