CNC Deep Hole Drilling with the Quadruple Zone Technique

Abstract

Abstract Generally, in CNC machining operations, drilling of holes is handled by special canned cycles available in all modern CNC controls. These cycles offer to the user, the capability of programming the required data of drilling in the form of parameters. Hole position, depth of hole, setup clearance, plunging depth and cutting feedrate are all expressed as parameters in the structure of the respective canned cycle. The specific canned cycles are intended to accommodate all drilling demands regardless of the hole’s depth. However, to achieve a successful result, when the case comes to deep holes, cutting conditions need to be adapted accordingly and dynamically as the tool advances from the top surface to the deeper levels of the hole. Unfortunately, the existing drilling canned cycles lack of similar flexible capabilities due to their standard programming framework. The present work proposes the quadruple zone technique that bypasses the limits of the existing canned cycles and offers to the operator the capability of defining different cutting conditions at four consecutive depth zones, leading in this way to an effective and smooth deep hole drilling. The technique is implemented in the form of a G-code parametric programming algorithm.