Drill wear monitoring by vibration signature analysis

Abstract

The useful life of a cutting tool and its operating conditions largely controls the economics of the machining operations. Hence, it is imperative that the condition of the cutting tool, particularly some indication as to when it requires changing, to be monitored. The largest amount of money spent on any one class of cutting tools is spent on drills. Monitoring of drills is an important task with a high degree of economical relevance; this is true especially for the use of twist drills, which are mostly used in a diameter spectrum between 1 mm to 20 mm. The paper deals with the comparative quality and performance analysis of the twist drills at different cutting condition as per the model, designed according to the factorial design method. Experiments were performed by using two twist drills of different make, possessing the same specifications. Drilling experiments with 14 mm drill size were performed at two cutting speeds and feeds. Selected values of controlling parameters (cutting speed, viscosity of lubricant, feed and number of holes) at each set of experiment shows their significant effect after regression analysis and is concluded along with the response parameters. Hardness values were measured for the drills at different locations and the conclusions are drawn by the frequency response analysis and surface roughness.