An integrated Reaction Wheel Assembly Array (RWAA) includes a multi-rotor chassis having a plurality of bearing locating features. A plurality of rotor assemblies is mounted to the multi-rotor chassis. Each rotor assembly includes a rotor having a rotor shaft, a spin motor coupled to the rotor and configured to drive rotation of the rotor about a spin axis, and a first spin bearing assembly disposed around an end portion of the rotor shaft. The first spin bearing pilots to one of the bearing locating features to position or locate the spin axis of the rotor assembly in a predetermined fixed spatial relationship relative to the spin axes of the other rotor assemblies.