Inspection of components manufactured on a machining centre, by on- and off-line techniques

Modern machining centres have the potential to be utilised as accurate measuring instruments in a production environment. This work reports an an investigation into analysing their capability to perform co-ordinate measuring machine (CMM) style inspection procedures. Research was undertaken to analyze the current capabilities of such a machine utilising the in-site touch-trigger probing system. A comparison was made between measurements taken on the machine tool, to those obtained using a CMM - this technique has been termed "foot-printing". The machine tool's probe and that on the CMM were manufactured by the same company - although it was anticipated that the unit fitted to the CMM: would out-perform that utilised by the machining centre. Specific features were inspected on the specially designed components manufactured from aluminium and steel, these being machined at varying feedrates. The errors arising as a result of such variations in the machining processes, were analyzed to find the conditions where both maximum and minimum errors occurred. The reasons why and where such errors occurred in the final parts are discussed and mention will be made of how these errors can be minimised and as such, establishing the factors to improve component accuracy.