Prediction of cutting force for precise control of thrust force during turning processing

In this study, we propose the new equations which predict cutting forces under the conditions of a small feed (2.5μm) and negative approach angle. They are based on Nakayama's equations. According to our previous research, the experimental cutting forces were larger than the calculated forces with Nakayama's equations. The differences were caused by size effect. One of the causes of size effect was a cutting edge radius. Therefore, the new equations were formulated with taking into account the cutting edge radius. The cutting force calculated by the new equations were approximately equal to the experimental results. The accuracy of the new equations is validated under the conditions of thrust force free cutting.