Architecture for Direct Model-to-Part CNC Manufacturing
In the traditional paradigm for Computer Numerical Control (CNC) machining, tool paths are programmed offline from the CNC machine using the Computer-Aided Design (CAD) model of the workpiece. The program is downloaded to the CNC controller and the part is then machined. Since a CAD model does not exist inside the CNC controller, it is unaware of the part to be machined and cannot predict or prevent errors. Not only is this paradigm labor intensive, it can lead to catastrophic damage if there are errors during machining. This paper presents a new concept for CNC machine control whereby a CAD model of the workpiece exists inside the controller and the tool positions are generated in real-time by the controller using the computer’s graphics hardware without human intervention. The new concept was implemented on an experimental lathe machine specifically designed to machine complicated ornamental wood workpieces with a personal computer. An example workpiece was machined and measured using a 3D camera. The measured data was registered to the CAD model to evaluate machining accuracy.
Single controlled axis lathe mill
This work presents a method for machining complex three-dimensional surfaces using only one axis of controlled motion for positioning a cutting tool on a specially designed numerically controlled (NC) machine. This single controlled axis lathe is configured like a lathe, but is used to produce complex sculptured surfaces out of wood. This is accomplished by mechanically linking two axes of motion to produce a fixed helical footprint of a tool path with constant step-over distance. As the linked axes are rotated, their location is measured by an encoder and passed directly to a personal computer (PC). Software running on the PC determines the depth of the computer-controlled axis. The depth information is used to control the depth axis. Several test pieces have been machined out of cedar for evaluating the method.
NC machining with G-buffer method
The G-buffer method is applied to NC machining. A total NC system is created that consists of all essential functions, such as tool path generation, path verification, and feed rate control. Moreov...