Investigation for the Affecting Factors on the Straightness Measurements for large CNC Machine Tools

Abstract The machine tools has main role in high production quality level of industrial products. Inorder to save and increase this high quality of production level, the geometric errors of machine tools have to measured, determined and controlled. Straightness errors are one of the most important type of geometric errors of machine tools. The measurements of straightness errors i.e. horizontal and vertical straightness errors are affected by various factors. The straightness errors are measured versus three important factors. These factors are different location positions, different moving steps and different analysis methods. Among the sex latches of machine tool in this paper, the straightness errors in X axis at latch 3 has minimum values. The straightness errors in Z axis at right position about 2000 Ømm (1000 mm) from the machine center has also mimimum values. Straightness errors are measured at moving steps, 50, 100, 150 and 200 mm. Such errors have minimum values at moving step 50 mm. Regression, end-point fitting and ISO1101 are three mathematical tools that used in determination of straightness errors.