Integration of an open architecture controller with a diamond turning machine

Abstract

Older machine tools are often mechanically sound but their proprietary controls are outdated and can be economically upgraded to modern open architecture control. The objective of this paper is to present a procedure for integrating these new flexible control architectures into machine tools. As an example, this paper presents the integration of an open architecture controller and a diamond turning machine. The open architecture control permits research into various types of control such as position, velocity, force, and adaptive control that will improve the quality of manufactured optics and other high precision components. The goal of incorporating an open architecture controller into an existing diamond turning machine required the identification, integration and installation of many components. After installing these components, the machine was calibrated to improve its performance. The most important aspect in improving the overall performance of the machine was correcting its vibration characteristics. Spindle imbalance, the spindle shaft coupler and the table and slide amplifiers were found to play a significant role in producing vibration. The sidewise amplitude of acceleration was reduced from approximately 2.5 to 0.6 g due to reduction in vibration after correcting these sources. The remaining level of vibration is normal for this type of diamond turning machine allowing it to produce finishes with 90.24 nm (3.56 μin) RMS surface roughness using a radius tool and 24.13 nm (0.95 μin) RMS with the straight-edge tool.