A technique triggers optimization of a traffic engineering label switched path that spans multiple domains of a computer network from a head-end node of a local domain to a tail-end node of a remote domain. The rotating shafts are coupled together by engagement between an engagement convex portion and an engagement concave portion which are formed respectively in shaft ends of the rotating shafts. A first clip leg is connected to the engagement flange. In yet other embodiments, the drill collar can be made of a metallic frame structure with a multiplicity of openings which are filled with a composite material. The quilting rack and legs are foldable and, combined with the rotatable vertical support, provide for convenient transportation and storage of the quilting machine.