Mathematical Modeling to Predict Surface Roughness in CNC Milling

Authors: Ab. Rashid M.F.F., Gan S.Y., Muhammad N.Y.

Abstract:

Surface roughness (Ra) is one of the most important requirements in machining process. In order to obtain better surface roughness, the proper setting of cutting parameters is crucial before the process take place. This research presents the development of mathematical model for surface roughness prediction before milling process in order to evaluate the fitness of machining parameters; spindle speed, feed rate and depth of cut. 84 samples were run in this study by using FANUC CNC Milling α-Τ14ιE. Those samples were randomly divided into two data sets- the training sets (m=60) and testing sets(m=24). ANOVA analysis showed that at least one of the population regression coefficients was not zero. Multiple Regression Method was used to determine the correlation between a criterion variable and a combination of predictor variables. It was established that the surface roughness is most influenced by the feed rate. By using Multiple Regression Method equation, the average percentage deviation of the testing set was 9.8% and 9.7% for training data set. This showed that the statistical model could predict the surface roughness with about 90.2% accuracy of the testing data set and 90.3% accuracy of the training data set.

Keywords: Surface roughness, regression analysis.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1060948

References:

[1] Julie Z.Zhang, Joseph C.Chen, E.Daniel Kirby, Surface Roughness optimization in an end-milling operation using the Taguchi design method, 27 January 2006
[2] Dr. Mike S.Lou, Dr. Joseph C. Chen & Dr. Caleb M.li, Surface Roughness Prediction Technique For CNC End-Milling, January 1999
[3] Oğuz çolak, Cahit Kurbanoğlu, M. Cengiz Kayacan, Milling surface roghness prediction using evolutionary programming methods, 7 July 2005