A miniaturized turbogenerator (200) to directly provide electrical propulsion (307 308, 309) to small land, air, and maritime vehicles without an intervening electricity storage battery (315). The invention comprises of a process of miniaturization (500) of a turbine engine core (100), in particular its compressors and turbines (400), by means of hyper-feed machining by linear force alone, i.e. without rotation of either the workpiece or the cutting tool (505), and a resulting apparatus of a miniaturized turbogenerator (200) that has sufficient power density to provide high-performance electrical propulsion (310) for commercially feasible automobiles, urban air mobility vehicles, and other small vehicles and vessels with greater performance than battery-electric vehicles (300).