Garage door industry magazine for garage door dealers, garage door manufacturers, garage door distributors, garage door installers, loading docks, garage door operators and openers, gates, and tools for the door industry.
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58 International Door & Operator Industry™ both cables are cut to the same length. Even when using the fnest cable cutters available, the ends of the cable may still fray when cut in the feld. These frayed ends can cause other problems when the fttings are swaged on to the cable (discussed later under "swaging the stop end"). Most pre-made cable assemblies produced at factories in the USA utilize specialized equipment to ensure the cut length is accurate, and the end is "electrically cut" to fuse the ends to prevent frayed ends (see Figure 2). Forming and Swaging the Loop End: The key points for this operation include: 1) use of the proper sleeve for diameter of cable; 2) cable must extend through the sleeve; 3) forming an accurate loop size; and 4) apply proper swage to the sleeve with the proper tool. When fabricating a cable assembly in the feld, this is probably the most diffcult operation to perform since it takes an extra set of hands to do it properly. One set of hands is needed to hold the cable and sleeve in place to maintain the proper loops size and, and another set of hands is needed to compress the handles of the swaging tool. Additionally, the size of the loop is important. If the size of the loop is too large, the cable could jump off the bottom bracket. If the size of the loop is too small, the cable might be damaged when it is forced on to the bottom bracket. Swaging the Stop End: The key points for this operation include: 1) use of the proper stop for diameter of cable; 2) cable must extend through the stop; 3) make sure there are no frayed wires bent back inside the stop prior to the swage; and 4) apply proper swage to stop with the proper tool. When fabricating a cable assembly in the feld, care must be taken to make sure there are no frayed wires bent back into the stop prior to swaging. In the case of 7x19 cable, all 133 wires must extend through the cable without being bent back. Think of it as threading a needle with 133 wires through one hole. If a single wire is bent back inside the stop when the swage is made, this will lock stress into the cable. This stress will eventually be released causing the cable to unravel (see Figure 3). Swaging Basics for Sleeve and Stops & the Lesson Learned by Bob the Technician: A cable swagger is a necessity! There are several types available from various suppliers that can be easily carried and maintained in your service vehicle. The key to a good swage in the feld is to use the proper groove in the swaging tool for the applicable diameter cable. Do NOT swage by hitting the sleeve or stop fat with a hammer. An improper swage can crush the strands of the cable which will cause the cable to unravel. The unraveling of the cable from an improper swage may not appear immediately, but it will eventually occur after the door has been in operation. Here is a real life example of a technician learning this the hard way. A technician (let's call him Bob) replaced a door cable by fabricating his own cable assembly in the feld. After the door had been back in service for a short time, Bob received a call from the homeowner indicating the cable had a problem again. Bob returned to fnd the cable was a big mess (see Figure 4a). Bob promptly returned the cable to his bulk cable supplier proclaiming "you sent me some bad cable." Upon closer examination, it was found that Bob had swaged the stop end my hitting it with a hammer creating a fat swage (see Figure 4b). Bob's hammer swage smashed the strands of the cable which meant Bob had unknowingly damaged his cable machine. It turned out the bulk cable was just fne. Bob actually created this big mess by not using the proper tool. Continued on page 60 Figure 2 - Electrically Cut Cable Figure 3 - Unraveled Cable Figure 4a - Result of Improper Swage - Big Mess Figure 4b - Cause of Big Mess - Improper Swage TECHNICAL (continued from page 56) 1/24/14 10:54 AM