Drill Point Designing by Computer

Abstract

One of the major problems related to the setting of a drill point grinder is the general lack of information on the correct grinder setting parameters to achieve a particular drill point configuration. Generally, the setting of such grinders is based on trial and error. Apart from being time consuming this procedure often produces results which are inconsistent. This paper presents a method for determining the conical drill point grinder setting parameters with the aid of a computer, from the following input data related to the drill point geometry: drill diameter, web thickness, point angle, chisel edge angle, peripheral side clearance angle and inner side clearance angle. The expected error of each of the drill point parameters due to the grinder setting errors is calculated. The drill cutting edge straightness is analysed and a curvature value is defined. The computer print-out lists the drill grinder setting parameters on request and produces graphical presentations of the resultant drill point configuration, with the expected errors in the drill point parameters. Typical results are included in the paper.