Topology of Spade Drills for Wood Drilling Operations Part 2: Spade Drill Point Cutting Geometry Analysis

Abstract

Based on the spade drill point’s mathematical models established in Part 1 of this paper, a detailed methodology for the analysis of the cutting edges and angle distributions along these edges is given. The analysis addresses the most important geometric elements of the bit including the tip, major cutting edge, and the chisel edge profiles, as well as the rake and clearance angle distribution along these cutting edges. In unison, the geometric model of the spade bit and the analysis procedure described in this part of the paper have laid the foundation for a methodology and a software package for a detailed geometric analysis of all relevant cutting mechanics related geometric entities of the drill. This, in turn, constitutes the first prerequisite for assessing the cutting performance of these tools.