An apparatus comprising: a housing (120; 520) comprising an upper surface and a lower surface substantially parallel to the upper surface and a longitudinal slot; a reciprocating bracket at the longitudinal slot of the housing (120; 520) and configured to travel back and forth along the longitudinal slot and in a direction substantially parallel thereto; a first set of cables affixed to a base at an opening of the housing (120; 520), the first set of cables entering the housing (120; 520) through the opening and extending within the housing (120; 520) in a first direction; a second set of cables affixed to the base at the opening of the housing (120; 520), the second set of cables entering the housing (120; 520) through the opening and extending within the housing (120; 520) in a second direction transverse to the first direction; the first set and the second set of cables exiting the housing (120; 520) through the longitudinal slot, the first set and the second set of cables further converging toward, and affixed to, the reciprocating bracket at the longitudinal slot; one or more first barriers within the housing (120; 520) adjacent the first set of cables configured to maintain a first spatial separation therebetween; separators affixed to each of the first and second set (506, 508) of cables and configured to maintain central axes of each of the first and second set (506, 508) of the affixed cables in a linear orientation perpendicular to the upper surface and the lower surface of the housing (120; 520); wherein the separators comprise generally planar upper and lower surfaces and a height slightly smaller than a distance between the upper surface and the lower surface of the housing (120; 520) configured to prevent the separators from rotating excessively within the housing (120; 520); and one or more second barriers within the housing (120; 520) adjacent the second set of cables configured to maintain a second spatial separation therebetween. a housing (120; 520) comprising an upper surface and a lower surface substantially parallel to the upper surface and a longitudinal slot; a reciprocating bracket at the longitudinal slot of the housing (120; 520) and configured to travel back and forth along the longitudinal slot and in a direction substantially parallel thereto; a first set of cables affixed to a base at an opening of the housing (120; 520), the first set of cables entering the housing (120; 520) through the opening and extending within the housing (120; 520) in a first direction; a second set of cables affixed to the base at the opening of the housing (120; 520), the second set of cables entering the housing (120; 520) through the opening and extending within the housing (120; 520) in a second direction transverse to the first direction; the first set and the second set of cables exiting the housing (120; 520) through the longitudinal slot, the first set and the second set of cables further converging toward, and affixed to, the reciprocating bracket at the longitudinal slot; one or more first barriers within the housing (120; 520) adjacent the first set of cables configured to maintain a first spatial separation therebetween; separators affixed to each of the first and second set (506, 508) of cables and configured to maintain central axes of each of the first and second set (506, 508) of the affixed cables in a linear orientation perpendicular to the upper surface and the lower surface of the housing (120; 520); wherein the separators comprise generally planar upper and lower surfaces and a height slightly smaller than a distance between the upper surface and the lower surface of the housing (120; 520) configured to prevent the separators from rotating excessively within the housing (120; 520); and one or more second barriers within the housing (120; 520) adjacent the second set of cables configured to maintain a second spatial separation therebetween.