Abstract: A method of making a cylindrical electrical conductor or roving comprised of a bundle of conductive glass filaments, wherein the filaments are cured under tension in a flat ribbon-like form. The method includes binding the filaments into a preferred cylindrical bundle or roving by the steps of passing the filament bundle through the axial bore of an annular bobbin having a binder yarn or element thereon and rotating the bobbin to centrifugally throw the yarn in an unconfined balloon. The free end of the yarn is secured to the filament bundle, thereby wrapping the bundle with a helical overwrap. The balloon of yarn is controlled and stabilized by air currents generated adjacent the bobbin.