Research on the Parametric Design and Manufacture of Spherical Tungsten Carbide Burs Using a Five-Axis CNC Grinding Machine

The tungsten carbide burs (TCBS) and diamond burs (DBS) are two mainly tools in clinical dentistry, while the TCBS possess many advantages over the DBS. The main goals of this paper were to parametrically design and manufacture a series of spherical tungsten carbide burs (STCBS) with 0.5mm to 3mm diameter, and the burs have an "S" shape cutting edges with six or eight flutes. The major cutting edges are modeled based on the mathematical model of the "S" shape curve, and the transition cutting edges are formed by 3-D interpolation between two points located at the spherical surface. A modular design flow is used to establish a series of 3-D models with different parameters of diameter, edge number and geometric angles. As an application, the manufacture of a spherical tungsten carbide bur (STCB) with 2.3mm diameter and 8 flutes is presented. An automated technique is developed to determine G-Code generated by tool path through the UG post process unit according to an available 5-aixs CNC grinding machine tool. The simulation is carried out using a commercial software package VERICUT, which shows the tool path meets the machining precision and is no overcut as well as interference between the bur and the process system of the machine tool.