Process for qualifying accuracy of a numerically controlled machining system

摘要

Positioning errors of a numerically controlled machine and a fixture are related through a mathematical model to the statistical total error in the position of the machine tool, and maximum allowable amounts are assigned for each of the individual contributing factors to the total error. The relationship between the machine and fixture is checked by a probe mounted in the machine spindle. Functioning and alignment of the probe are checked with the probe. Global positioning accuracy of the machine is checked throughout a working envelope of the machine using a laser measuring instrument. A master coordinate system relative to the ways of the machine is created within the laser instrument by calculating a linear fit of machine position coordinates acquired as the machine is moved along each of two perpendicular axes of the machine, and the master coordinate system is used for the global accuracy and fixture accuracy checks.