In a line card assembly, an optical fiber spool is mounted directly onto the back of a line card panel, thereby avoiding the use of a printed circuit board as a structural base. The line card assembly includes a hub having an outer circumference and first and second ends, and a longitudinal axis extending between the first and second ends. First and second plates are located, respectively, at the first and second ends of the hub, transversely to the hub's longitudinal axis. Each of the first and second plates has an outer perimeter including at least one straight outer edge, a straight outer edge of the first plate being aligned with a straight outer edge of the second plate, such that the hub, first plate, and second plate together form a spool with at least one squared-off side. A collar is mounted to the first and second plates, the collar extending at least part way around the perimeter of the first and second plates. The collar includes a structural interface for attaching a line card panel thereto, the attached line card panel covering the squared-off side of the spool, the first plate, second plate, collar, and line card panel forming an enclosure around an optical fiber wound onto the hub.