AiVibeFeed Rate
Feed rate is the speed at which the cutting tool advances relative to the workpiece, programmed with the F word. Milling usually uses millimetres per minute; turning usually uses millimetres per revolution.
In milling, table feed vf in millimetres per minute equals feed per tooth fz times the number of teeth z times spindle speed n. In turning and drilling, feed is usually expressed per revolution, fn in millimetres per revolution. CNC controls provide feed-per-minute and feed-per-revolution modes, and the F word sets the value for G01, G02, G03 and cycle moves, while rapid moves run at the machine's rapid rate.
Feed rate, with cutting speed and depth of cut, determines chip thickness, cutting forces, power demand, cycle time and surface finish. In turning with a rounded insert, the theoretical peak-to-valley roughness is approximately the feed squared divided by eight times the nose radius, so finishing passes use lower feeds or larger nose radii.
Too low a feed causes rubbing, heat and work hardening, while too high a feed overloads the cutting edge. Actual feed may fall below the programmed value in corners and on short segments because of acceleration limits and look-ahead behaviour. Operators can adjust feed with the feed override, and adaptive feed control systems can vary it automatically based on spindle load, within limits set by the programmer.
Key points
- Milling feed vf = fz x z x n, usually in mm/min
- Turning feed is usually given per revolution in mm/rev
- Theoretical turned roughness rises with the square of the feed
- Acceleration limits can make actual feed lower than programmed
Where AiVibe comes in
AiVibe designs and manufactures the AiAmbA AI Factory: edge devices plus AI agents that let people talk to CNC, PLC and robot controllers in plain language. Agents only propose changes, and a trained operator confirms each one.
Related terms
- Chip Load (Feed per Tooth, fz)CNC & Precision Machining
- Spindle Speed (RPM)CNC & Precision Machining
- Cutting Speed (Surface Speed, Vc)CNC & Precision Machining
- Depth of Cut (ap and ae)CNC & Precision Machining
- Surface Roughness (Ra, Rz)CNC & Precision Machining