Influence of Fixtures on Dimensional Accuracy in Machining Processes

The main function of fixturing devices in machining processes consists of locating a workpiece on a work table in a machine tool. As well as having a locating function, fixtures must also ensure that the dimensional quality of the manufactured workpiece can be achieved. In this paper, a methodology is described for calculating the real value of critical dimensions and the intrinsic inaccuracy involved in the manufacture of parts, as a function of the dimensional variables of fixtures. The methodology is based on the accuracy of fixtures and workpiece, the positioning of locating points and the error transmission chain.