Directional factor as the key factor for chatter free robotic milling of light alloys

Abstract

Robotic milling systems are increasingly used for light alloys and composites, but face challenges due to high dynamic flexibility of robots. A key issue is low-frequency chatter, linked to the robot's structural modes during high-speed operations. Therefore, this study deals with a dominant flexible mode with high tooth-passing frequencies, highlighting the influence of the directional factor. Negative directional factors can cause low-frequency chatter at high spindle speeds. Polar stability lobes show that optimal feed direction and radial engagement zones align with positive directional factors. The study shows that slotting operations assure a chatter free machining. Experimental validation confirms theoretical findings.