A mathematical model for simulating and manufacturing ball end mill
The performance of ball end mill cutters in cutting operations is influenced by the configuration of the rake and clearance faces in the ball component. From the mathematical design of a cutting edge curve, the rake face can be defined by the rake angle and the width of the rake face at each cross section along the cutting edge. We propose the fundamental conditions that must govern the engagement between the grinding wheel and the designed rake face in order to avoid interference while machining a ball end mill. As a result, a new mathematical model for determining the wheel location and a software program for simulating the generation of the rake face of a ball end mill are proposed. In addition, methods for grinding the clearance face in both concave and flat-shapes are introduced. The flute surface generated by a disk wheel during the grinding process is determined on the basis of a tangency condition. The results of the experiment and the simulation are compared to validate the proposed model.
CNC Rake Grinding for a Taper Ball-End Mill with a Torus-Shaped Grinding Wheel
A new grinding method using a torus-shaped grinding wheel and a machining path generation method with a novel moving coordinate system are proposed. With this new grinding method, the smooth spiral rake surface of a taper ball-end mill with constant helical angle and constant normal rake angle can be formed during one grinding process and the normal rake angle can be obtained accurately. The novel moving coordinate system is established based on taking account of both the cutting edge curve and the cutter body surface. By means of the novel moving coordinate system, the machining path generation becomes very simple. The proposed grinding method and the machining path generation method are verified by 3D simulation results.
Swept volume generation for the simulation of machining processes
To enhance the accuracy of five-axis milling processes, a simulation based NC-path optimization provides an efficient approach. The key to a reliable simulation of cutting processes is the accurate geometric modeling of engagement conditions and the resulting workpiece geometry. The article proposes a novel approach to calculate the cutter profile for modeling swept volume with respect to trajectory of the cutter. In terms of envelope theory, a swept volume is created as a NURBS surface representation. The proposed method is robust and the results can be applied to material removal simulations based on Boolean operation, as well as discrete methods.