Abstract: A gyroscope rotor is rotated to a very high speed when a pawl is moved to release a ratchet coupled to a coil spring drive and keyed to a drive shaft. The coil spring drive then drives the rotor at a multiplied rate of speed through an arbor, planetary pinions revolved by the arbor and meshing with a fixed ring gear, a sun gear keyed to a drive shaft, the drive shaft, and hooking claw clutch teeth on the drive shaft and the rotor. When the spring reaches an unwound condition, the rotor overruns the drive shaft, the clutch teeth on the rotor cam the drive shaft axially away from the rotor, and a compression spring moves the drive shaft and a pilot pin thereon to retracted positions completely out of engagement with the rotor. A keeper bar on the pawl normally overhangs the ratchet to hold the drive shaft in clutching engagement with the rotor, and, when the pawl is released, it moves the keeper bar to a retracted position permitting axial movement of the drive shaft.