A dedicated CAD/CAM module for high-precision CNC milling of complex threads

Abstract This paper introduces a dedicated CAD/CAM module specifically designed for high-precision CNC milling of complex threads with variable radius and/or pitch and selectable number of turns. The module comprises two interconnected components: a CAD unit and a CAM unit. The CAD unit provides visual representation by enabling efficient rendering of the target helix. The CAM unit integrates a high-precision CNC interpolation algorithm capable of generating tool paths with deviation no greater than the CNC machine’s step resolution—achieving machining precision limited only by the physical hardware. This innovative CAD/CAM module significantly enhances the motion capabilities of CNC milling machines, offering a powerful programming solution for applications requiring precise control over complex thread geometries. Unlike standard CNC controllers, which are typically restricted to fixed-radius and fixed-pitch helical interpolation, the proposed method enables dynamic adjustments to both parameters. This flexibility greatly expands its potential applications. The module's performance, reliability, and high machining accuracy are thoroughly validated through simulation tests and a real machining trial conducted on a modern CNC milling machine.