An innovative canned cycle for helical milling cylindrical holes with adjustable pitch, radius, and turns

Helical interpolation is widely used in CNC machining for drilling, threading, and milling operations, but conventional helical cycles with fixed-pitch and fixed-radius motion limit adaptability to varying machining conditions. This paper presents an innovative canned cycle for helical milling cylindrical holes with adjustable pitch, radius, and turns, enabling precise control over the drilling process. The method allows for variations in these parameters at different depths, providing flexibility in machining strategies. Additionally, the cycle enables the programming and adjustment of feed rate and spindle speed at different depth levels, allowing for high feed rates at the start and progressively lower feed rates with increased spindle speed at deeper sections. A key advantage is the ability to start with a smaller radius and gradually increase it to the desired hole radius while simultaneously applying a high-to-low pitch approach, effectively combining roughing and finishing in a single pass. This method aims to facilitate smooth tool penetration, reduce wear, enhance machining precision, and ensure optimized material removal. The proposed cycle is implemented on a modern CNC controller, where simulation scenarios validate its performance.