In one arrangement, a motor assembly includes a housing defining a housing chamber, a stator disposed within the housing chamber, and a rotor assembly disposed within the housing chamber. The rotor assembly includes a spindle housing defining a spindle housing chamber extending along a longitudinal axis of the spindle housing and a set of magnets disposed about an outer periphery of the spindle housing and in proximity to the stator. The rotor assembly includes a ball nut cartridge disposed within the spindle housing chamber of the spindle housing and a securing mechanism configured to secure the ball nut cartridge to the spindle housing.