Equal Spacing Starts With Dividing the Circle
Indexing a rotary table for equally spaced features, like a bolt circle of holes or a series of flutes, just means dividing 360 degrees evenly by however many features you need, which is the same idea as a manual dividing head but applied to a CNC 4th axis. The rotary move between each position takes time too, so the move isn't instantaneous even though it's often small.
Dwell Time Protects Accuracy
A short dwell after each rotary move lets any residual vibration or servo settling finish before the cutter engages, which matters more on lighter rotary tables or larger, heavier workpieces where momentum can carry the table slightly past its commanded position. Skipping dwell to save a fraction of a second per index rarely saves meaningful cycle time but can cost accuracy on tight-tolerance work.
Estimating Full-Circle Cycle Time
Adding the rotary move time, dwell, and the actual machining time per feature together for every division gives a realistic total cycle time estimate, which is useful for quoting a job or comparing how much indexed-rotary work would cost in machine time versus doing the same pattern as a continuous interpolated path.