Abstract: An assembly for carrying out operations in the transfer, manufacture, or assembly of components having an open center turntable, rotatable about a vertical axis, having a number of work positions adapted for alignment with component supply, assembly, and removal. The platform is movably borne on an open center fixed base support, by means of bearings journalled between the support and the turntable proximate the work force exerted on the component at the turntable work station. The platform is rotated about the open center fixed support by means of a substantially circular drive hub attached to the platform. A drive belt, coupled to the drive pulley of a motor, located beneath the platform peripherally engages the drive hub about a circular belt raceway attached to the hub. As the drive pulley rotates, the turntable rotates through a defined set of motions by means of the drive belt arrangement.