A motor-generator includes a rotor that rotates about an axis of rotation, and a stator that is stationary and magnetically interacts with the rotor. The rotor is constructed of two spaced apart rotor portions having magnetic poles that drive magnetic flux across an armature airgap formed therebetween. An armature, located in the armature airgap, has a substantially nonmagnetic and low electrical conductivity form onto which wire windings are wound. The form has a free end that extends inside the rotor, and a support end that attaches to the stationary portion of the motor-generator. The form is constructed with a thin backing portion and thicker raised portions extending from the backing portion in the direction of the magnetic flux. The wire windings have multiple individually insulated conductor wire. The conductors of a single wire are electrically connected together in parallel and electrically insulated between each other along their length inside the armature airgap. The wire windings are wound on to the form by inserting the wire to lie between the raised portions; the form provides position location and support for the wire windings during the winding process, and subsequently reacts the electromagnetically induced torque on the windings to the stationary portion of the motor-generator through the support end of the form and prevents the windings from contacting the rotor portions during rotation of the rotor.