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High precision manufacturers continuously seek out disruptive technologies to improve the quality, cost, and delivery of their products. With the advancement of machine tool and measurement technology many companies are ready to capitalise on the opportunity of on-machine measurement (OMM). Coupled with business case, manufacturing engineers are now questioning whether OMM can soon eliminate the need for post-process inspection systems. Metrologists will however argue that the machining environment is too hostile and that there are numerous process variables which need consideration before traceable measurement on-the-machine can be achieved. In this paper we test the measurement capability of five new multi-axis machine tools enabled as OMM systems via on-machine probing. All systems are tested under various operating conditions in order to better understand the effects of potentially significant variables. This investigation has found that key process variables such as machine tool warm-up and tool-change cycles can have an effect on machine tool measurement repeatability. New data presented here is important to many manufacturers whom are considering utilising their high precision multi-axis machine tools for both the creation and verification of their products.

Holography has been developed by Rolls-Royce as a technique for routine use in the evaluation of fan designs for aeroengines. It is used to investigate both aerodynamic and mechanical behavior of the rotating fan. Holographic flow visualization provides clear, three-dimensional images of the transonic flow region between the fan blades. Flow features such as shocks, shock/boundary layer interaction, and over-tip leakage vortices can be observed and measured. Holograms taken through an optical derotator allow vibration modes of the rotating fan to be mapped during resonance or flutter. Examples are given of the use of both techniques at rotational speeds up to and in excess of 10,000 rpm. Holography has provided valuable information used to verify and improve numerical modeling of the fan behavior and has been successful in evaluating the achievement of design intent.