Abstract: A servo-member includes a rigid body having first and second opposed planar surfaces. A hub is formed on the first surface. A first keyed bore is formed in the hub and terminates at an annular seat. The first bore has a first diameter. A recessed circumferential groove is formed in the first bore adjacent the seat. The groove has a second diameter which is greater than the first diameter. A counterbore is formed in the second surface. The counterbore is separated from the first bore by the annular seat. The seat includes an opening which passes through the seat and interconnects the first bore and the counterbore.

Abstract: A servo-wheel for use in a control system for model craft having a servo-motor and movable control members. The servo-wheel is a rigid disc having opposed planar surfaces. A hub is at the geometric center of the disc and includes a bore extending through the disc. A raised portion protrudes from one of the planar surfaces and forms a first part of the hub. The raised portion also defines a first part of the bore having an inner circumferential surface of a first diameter. A keyed receiver is formed in the inner circumferential surface of the raised portion. An insert is mounted in the disc to form a second part of the hub. The insert defines a second portion of the bore and has an inner circumferential surface of a second diameter, less than the first diameter. A keyed driver is received by the keyed receiver. The keyed driver is rotatably connected to the servo-motor at one end and attached to the servo-wheel hub at the other end, so that the servo-wheel is rotated by the servo-motor.