A Study of Precision Thread Grinding : In Case of Using a Magnetic Standard Scale

Abstract

This paper presents a process of obtaining a leadscrew of higher lead accuracy in thread grinding. Leadscrews used for machine tools or length measuring machines often act as a standard scale for table positioning. They are ground after hardening. With the development of NC machine tools, they are required to have high level precision. This paper describes an improvement of the control system of the closed loop compensation device in the thread grinder. Thanks to the improvement a high pitch leadscrew of 800 mm in length can be obtained with a cumulative pitch error of 2.4 μm and a drunkenness of 2.0 μm. Furthermore, the causes of pitch error and drunkenness remaining after grinding are discussed.