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

Errors in machine tools can be categorized into three broad areas: (a) geometric errors, (b) thermally induced errors and (c) non-rigid errors. The categories cover imperfections in the machine tool structure, deviations caused by both internal and external heat sources and deflections due to loading of the structure respectively. This paper describes research into measurement strategies for the separation of the geometric and non-rigid errors into a suitable form to be utilized in a correction algorithm. The developed strategy was validated against machines of a similar configuration but varying in size.