Abstract In this study, the accuracy of a machine tool was evaluated by modeling the spherical deviation based on double ball-bar measurements under unloaded conditions. Circular measurement paths on the XY -, YZ -, and ZX- planes were planned, and three linear axis drives were commanded to follow the paths describing a nominal sphere. The spherical deviation, defined as the maximum radial range of deviations around a least-squares sphere, is affected by the accuracies of the three linear axes together. Therefore, the spherical deviation represents the accuracy of machine tools by quantifying the effect of the accuracies of three linear axes, whereas the circular deviation only quantifies the accuracies of two linear axes among the three linear axes. In this experimental study, spherical deviations of vertical/horizontal machine tools were measured and analyzed under various nominal lengths of a double ball-bar for various feed rates. The measurement uncertainty of the measured spherical deviation was investigated to determine the confidence interval.
[1]
J. B. Bryan,et al.
A simple method for testing measuring machines and machine tools Part 1: Principles and applications
,
1982
.
[2]
J.R.R. Mayer,et al.
A model based method for centering double ball bar test results preventing fictitious ovalization effects
,
2005
.
[3]
Seung-Han Yang,et al.
Analysis of eccentricity in the ball bar measurement
,
2010
.
[4]
Seung-Han Yang,et al.
Measurement and verification of position-independent geometric errors of a five-axis machine tool using a double ball-bar
,
2013
.
[5]
Robert Schmitt,et al.
Geometric error measurement and compensation of machines : an update
,
2008
.
[6]
Yoshiaki Kakino,et al.
The Measurement of Motion Errors of NC Machine Tools and Diagnosis of their Origins by Using Telescoping Magnetic Ball Bar Method
,
1987
.