Computer Aided Comparison of Out-of-Roundness Measures by Using Computer Generated Profiles

Authors: Can ÇOĞUN, Abdullah I. AL-NAJASHI

Abstract: Although, standard measures are defined and accepted as numerical indicator for out-of-roundness (OOR), no specific mathematical method, except for least square circle (LSC) method, is specified as how to get these measures. A software is developed to compare the OOR measures by the different techniques, namely, minimum zone circle (MZC), minimum circumscribed circle (MCC) and LSC, for the computer generated roundness profiles and to observe the effects of some variables of generated surfaces such as profile magnification and part radius on OOR readings. The software generates the roundness profile by using the user defined input parameters (i.e. harmonic order, amplitude and phase shift angle of harmonics, number of harmonics, part radius and OOR magnification) and then calculates OOR values by using LSC, MZC and MCC methods. It is observed that MZC method gives the least OOR value followed by LSC and MZC for the sample roundness profiles generated by the computer. It is also noticed that OOR value is affected by magnification factor of the profile, while the profile radius has no significant affect on OOR measurements.

Keywords: Out-of-Roundness, Least Square Circle, Minimum Zone Circle Method, Minimum Circumscribed Circle Method.