Abstract: A rearmable spring caged and energized free gyro which will allow repeated rearming for testing and use without requiring the opening of the main instrument enclosure, or requiring auxiliary sources of energy. The gyro is housed in an approximately cylindrical enclosure with the spin axis perpendicular to the axis thereof. A helical spring substantially coaxial with the enclosure is positioned adjacent one end of the enclosure, and may be wound through that end of the enclosure by an appropriate winding tool. During the winding of the spring a cam moves substantially coaxially along the inside of the enclosure, engaging a roller adjacent the end of the pitch axis which rotates the gimbal assembly around the roll axis to the roll axis caged position, at which time the end of the inner gimbal cooperatively references to the cam to align the spin axis.