Rotor poles are punched or fabricated from high-strength steel. The pole shape is designed to withstand mechanical stresses caused by rotational forces and prime mover pulsations. The pole contour is optimized to minimize harmonics in the voltage waveform.

Field coils are machine wound on the poles with high temperature rated insulated copper wires. The coil end and interpolar region are blocked to prevent coil movement and distortion. Depending upon the application, damper bars are inserted into the pole face and brazed or welded at each end to complete the damper/amortisseur winding. The purpose of the damper windings is to reduce the generator harmonics and absorb torque pulsations caused by the prime mover or an unbalanced load distribution. The damper windings also reduce system oscillations caused during parallel operation. The complete rotor is either vacuum-pressure impregnated before the shaft is pressed or wet wound.

The shaft is precision machined to meet the stringent tolerance requirements for runout and concentricity of the shaft’s bearing surfaces. The rotor is dynamically balanced to meet specifications.