The shop balancing procedure from setup through correction: the measure-and-correct cycle, correction methods, splitting a correction between available angular positions, and the residual unbalance verification test that proves a balance independent of the machine’s calibration.

How a low speed balancing machine works: the hard-bearing and soft-bearing architectures, the hardware that supports and drives the rotor, the plane weights the tolerance takes, how measured amplitude and phase become unbalance vectors, and whether a machine is adequate for a particular rotor.

The taxonomy of unbalance — static, couple, dynamic, and quasi-static — why couple unbalance is invisible to a single-plane measurement, why two correction planes are sufficient for any rigid rotor, and where the terms static balancing and dynamic balancing come from.

What unbalance is physically, the units and conventions that quantify it, which rotors qualify for single-plane treatment, and how the ISO and API balance tolerance criteria are constructed and compare — the fundamentals behind one of the most common jobs in a rotating equipment repair shop.