The use of existing machinery with in-built volumetric accuracy compensation software to deliver huge improvements in achievable accuracy is discussed. Volumetric accuracy is a measure of the ability of a machine to position accurately within a defined working envelope. It is a combination of the individual geometric errors inherent in any machine axis. Simulation software (ESP) written at the University of Huddersfield can be used to predict the machining performance of any 3-axis machine based upon calibration data. The work on the university machine has shown that a good one can be made better by implementing compensation.