The identification of non-rigid errors in a vertical machining centre

Errors in machine tools can be categorized into three broad areas: (a) geom etric errors, (b) thermally induced errors and (c) non-rigid errors. The ca tegories cover imperfections in the machine tool structure, deviations caus ed by both internal and external heat sources and deflections due to loadin g of the structure respectively. This paper describes research into measure ment strategies for the separation of the geometric and non-rigid errors in to a suitable form to be utilized in a correction algorithm. The developed strategy was validated against machines of a similar configuration but vary ing in size.