Section 11 — Balancing Rotors214Section 11 — Balancing RotorsThis section describes the procedure for performing balancingoperations. You will learn to:• Understand the balancing process• Select appropriate balancing settings• Set up a balancing job• Manually enter balancing values• Use the instrument's suggested balance weight calculationsMethods for Balancing RotorsYour instrument can balance rotors that are rigid and do NOT flexsignificantly at their operating speeds.An unbalanced rotor has an uneven mass distribution that causes therotor to vibrate when it rotates. Balancing a rotor requires correcting theuneven mass distribution by adding or removing weight to/fromprecisely calculated positions on the rotor.You can balance a rigid rotor in one or two planes. You can correct anyuneven mass distribution in the rotor by adding/removing weightsto/from one or two selected cross-sectional planes on the rotor.For single plane balancing, the mid-plane of the rotor is usually used asthe balancing plane. The planes at the extreme ends of the rotor areusually used for dual-plane balancing. However, other planes on therotor can also be used.The effect of a rotating weight (i.e. centrifugal force) increases with theradial distance of the weight. Consequently it is common to add weightto, or remove weight from, the rim of the rotor (rather than a positionclose to the center of rotation). Making weight adjustments at the largestpossible radial distance minimizes the amount of weight that needs tobe added to, or removed from, the rotor.
