Caring for Cables

Unprotected cables can twist, bind, and wear out fast. Machine tools, coordinate-measuring machines, palletizers, robots, ship-to-shore cranes, and laboratory medical equipment are just some of the applications for cable carriers. Cable carriers keep cables and hoses on translating and rotating axis from tangling and exceeding minimum bend radii. Carriers also help expel debris and prevent cable and hose jackets from touching the machine itself. A cable carrier consists of hinged plastic or metal links that articulate as a machine axis moves. The most common carrier arrangement is horizontal and unsupported. This configuration works well for short travel distances and gives the longest possible service life. Here, the upper run of the carrier moves without touching the lower run throughout the entire travel length. Maximum unsupported length is typically about 20 to 30 ft and depends on carrier type and cable fill weight. When travel length exceeds that of an unsupported installation, a guide trough and glide bar supports the upper run. Cable carriers can also hang or stand vertically. Side-mounted, rotary, multiple-nested carriers and combination motions are also possible. Cable carriers are an integral part of a machine and should be considered early in the design process. Gather necessary data about the installation including travel length, size and weight of cables and hoses, the operating environment (debris, heat, chemicals), and machine speed and acceleration. Select a carrier material. Metal carriers have higher tensile strength than plastic and hold up better under heavy fill weights. Metal carriers also withstand high temperatures. Plastic, in turn, weighs much less than metal. This cuts the amount of power needed to move the carrier and may eliminate complex support systems. Plastic also resists corrosion, is quieter in operation than metal, nonconductive, and needs no lubrication. Several plastic-carrier designs snap together without metal fasteners. Metal fasteners can