Development of an Open Architecture Controller for Vertical 3-Axis Milling Machine

Abstract

The trends in the NC machine tool development in the direction of open architecture control and "Direct Model Part" machining strategies. To bring the simplicity, portability, interoperability, adaptability and low cost necessitates the improvement and simplification of conventional NC machining processes. A major problem with the conventional numerical control is that the motion control in the NC machining operations are not efficient with the restrictive (ISO 6983) G and M code. G and M code were designed in the era when a paper strip was used to feed part program in NC machine, was designed to give the program in NC machine. Today the G-code programs are generated by computer-aided manufacturing (CAM) tools by the geometric data from computer aided design (CAD) tools as input. However, CNCs different manufacturers implement different versions of G-code and leads to lack any proprietary CAD-CAM-CNC integrated modules / software. An open architecture machine tools can be controlled directly from a computer, instead of having separate numerical control. As the technology advances in sensors, positioning methods and tool path programming techniques, the high-speed PC and controller or the drive in an open architecture controller technology is open to integrate all the new technologies in the future. This is possible due to the high processing speed and low cost of a modern computer. An open architecture NC tool paths are free of conventional ISO G and Mbased NC tool paths, but it is a file with the previously calculated positions of the relative position of the cutter relative to the workpiece in a logical order. The aim of present work is fabrication of prototype of an Open Architecture NC controllerfor Personal Computer-controlled vertical 3-axis NC milling machine for machining of sculptured surfaces of wooden artistic design. The sculptured surfaces are made by artisans on wood, clay or rocks manually which leads to lack in productivity and reproducibility of artisan’s design. Some dedicated CNC machines are available for machining sculptured surfaces but because of heavy cost these are not affordable by an artesian. So present work is to fabricate low cost CNC machine by developing PC Based Open Architecture Controller. The aim is to break the monopoly of commercially available vendor depended CAD/CAM integration which hinders the customization of NC machine tool with new control strategies, sensors and interfaces. Also the open architecture based NC system will be better affordable than the commercial NC system for sculptured surface machining.