“Error-budgetting” for high performance positioning in ultra-precision manufacture

In many manufacturing processes, surfaces are generated as a time record of the locus of the position of a localised ablation (or accretion) mechanism and errors in travel or position will be manifest as imperfections in manufactured form. Deterministic machining processes, based on tool/workpiece traverse loci, developed progressively to a level of repeatability of about 5-10μm. In order to achieve an improved machine design specification, it is necessary to assign appropriately improved error specifications for each parameter, according to the magnitude of the nominal error and judgement of the degree to which it and other errors may be reduced. This must address the likely scale of errors and balance the effort in attenuating each