Abstract: A disk or cup rotor for a low-inertia electric machine has a pair of support bodies of revolution either constituted by inner and outer coplanar annular disks or aligned cylindrical tube sections. An array of elongated conductors is provided on each face of the outer body with the outer ends of these conductors projecting beyond the outer periphery of this outer body. The inner ends of at least half of the conductors terminate in the annular gap between the bodies and are there joined to other such terminating inner ends, whereas the remaining inner ends extend across the gap to the inner body where they form commutator bars that themselves extend beyond the inner periphery of the inner body and are joined at weld nodes to the commutator bars on the other face of the inner body. Several such inner and outer bodies may be stacked to create a multiturn coil effect. The conductors may form simple, closed, or waved windings or combinations of these types of windings with plural support bodies.