Abstract
This study presents a novel method to monitor the cutting force in the end milling process by means of an air-driven spindle. This monitoring method is based on the rotational speed of the spindle without the use of dynamometers. A speed difference square method (SDSM) index is computed from the rotational speed difference of the end mill during the process. During the process, the cutting forces are simultaneously observed and compared to the SDSM index. During the cutting process, the correlation coefficient between the SDSM index and the cutting forces is analyzed, and the SDSM index in the process shoes a very high correlation with the cutting forces.
