A self-propelled movable object comprising: a plurality of rotor assemblies configured to rotate in clockwise and counterclockwise directions, each rotor assembly of said plurality comprising: a hub and a drive shaft, wherein the drive shaft is configured to cause rotation of the hub in a clockwise direction or a counterclockwise direction; and a plurality of rotor blades coupled to the hub and configured to rotate therewith in a horizontal plane of rotation along the clockwise direction or the counterclockwise direction to generate a propulsive force; wherein the propulsive force includes a lift component that provides lift to the self-propelled movable object, and is imparted via contact between the hub and the drive shaft; and characterized in that: the drive shaft is coupled to the hub by a mating connection of a first fastening feature and a second fastening feature either directly or via an adapter; wherein the first fastening feature comprises an aperture, a pair of guides and a pair of stops, and the second fastening feature comprises a pair of protrusions; and rotation of the hub imparts a rotational force component that is transmitted from the drive shaft to the hub via contact between the pair of protrusions and the pair of stops. a plurality of rotor assemblies configured to rotate in clockwise and counterclockwise directions, each rotor assembly of said plurality comprising: a hub and a drive shaft, wherein the drive shaft is configured to cause rotation of the hub in a clockwise direction or a counterclockwise direction; and a plurality of rotor blades coupled to the hub and configured to rotate therewith in a horizontal plane of rotation along the clockwise direction or the counterclockwise direction to generate a propulsive force; wherein the propulsive force includes a lift component that provides lift to the self-propelled movable object, and is imparted via contact between the hub and the drive shaft; and characterized in that: the drive shaft is coupled to the hub by a mating connection of a first fastening feature and a second fastening feature either directly or via an adapter; wherein the first fastening feature comprises an aperture, a pair of guides and a pair of stops, and the second fastening feature comprises a pair of protrusions; and rotation of the hub imparts a rotational force component that is transmitted from the drive shaft to the hub via contact between the pair of protrusions and the pair of stops. a hub and a drive shaft, wherein the drive shaft is configured to cause rotation of the hub in a clockwise direction or a counterclockwise direction; and a plurality of rotor blades coupled to the hub and configured to rotate therewith in a horizontal plane of rotation along the clockwise direction or the counterclockwise direction to generate a propulsive force; wherein the propulsive force includes a lift component that provides lift to the self-propelled movable object, and is imparted via contact between the hub and the drive shaft; and characterized in that: the drive shaft is coupled to the hub by a mating connection of a first fastening feature and a second fastening feature either directly or via an adapter; wherein the first fastening feature comprises an aperture, a pair of guides and a pair of stops, and the second fastening feature comprises a pair of protrusions; and rotation of the hub imparts a rotational force component that is transmitted from the drive shaft to the hub via contact between the pair of protrusions and the pair of stops. the drive shaft is coupled to the hub by a mating connection of a first fastening feature and a second fastening feature either directly or via an adapter; wherein the first fastening feature comprises an aperture, a pair of guides and a pair of stops, and the second fastening feature comprises a pair of protrusions; and rotation of the hub imparts a rotational force component that is transmitted from the drive shaft to the hub via contact between the pair of protrusions and the pair of stops.