Described herein are self-propel accessories for walk behind/push-driven machines/devices comprising: drive assembly motor(s) operatively connected to at least one power supply； at least one drive assembly for imparting drive from the drive assembly motor(s) to at least one accessory wheel assembly that is operatively connected to an output shaft of the drive assembly motor(s) and one of an axle or a drive engagement surface of the at least one accessory wheel assembly having accessory ground engagement wheel(s) coupled to at least one end of the axle for rotation therewith； a controller for the drive assembly motor(s) having an actuator for engaging the drive assembly motor(s)； and an attachment assembly for coupling the drive assembly motor(s), the at least one drive assembly and the at least one accessory wheel assembly to a housing of the push-driven machine or device in place of a wheel assembly/sub-assembly of the push-driven machine or device.
