Power and Stability Limits in Milling

Abstract The metal removal rate (MRR) in milling is typically limited by the dynamics of the tool-spindle combination or by the power. If the tool is stiff, the power is limiting, and the spindle stalls before chattering. If the tool is flexible, there is a spindle speed range where chatter is limiting. Many tools have some spindle speeds where chatter is limiting and others where power is limiting. This paper presents a new “power lobe” diagram which is independent of the workpiece material. Combined with the power curve for the spindle, this “stable power” diagram defines the achievable MRR for the entire machine dynamics.