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Our Assembly Practices
When we began building audio and video cable for a living several years ago, we started out using the tooling typical for a small-scale cable assembly business. In this case, that meant primarily a standard set of Canare tools--coax stripper, crimp dies, and a couple of crimp handles. Most people building Belden a/v cabling for consumer purchase are doing more or less the same thing; the tools are relatively reliable and inexpensive (about $300.00 for a stripper, a single set of dies, and a crimp tool). However, as we terminated more and more cable, we came to recognize a few things about that standard tooling that really could stand improvement.
After examining a lot of coaxial cable stripping and crimping equipment, we found ourselves stocking the shop with cable strippers and crimpers from Schleuniger, a Swiss company which is a world leader in wire and cable processing equipment. Schleuniger equipment isn't inexpensive--new strippers start at around $15,000, and even a simple crimp press is at least $3,000--but the capabilities of the Schleuniger equipment are really stunning.
Our shop now contains an assortment of Schleuniger strippers, which use a rapid spinning blade-and-gripper arrangement to precisely center a cable and make a series of cuts to specified lengths and depths; we are able to control the settings on these strippers down to 1/1000 inch, which allows for very fine adjustment to account for the peculiarities of the different cables. Although Canare specifies the same strip lengths for every cable, in practice, some require slightly different strip lengths from the others. For example, the braid on double-braid cables (e.g. LV-77S, 1505F) has a tendency to wind up protruding from the end of the crimp sleeve after cable assembly, making for a hairy mess (if the assembler doesn't notice the problem) or a long, slow "haircut" process with a pair of mini-snips (if he does). Using the Schleuniger strippers, we can account for small differences in strip dimensions required for different cable types; every cable has its own program setting, with all those issues taken into account. The high speed of the blade rotation, and the tightly controlled strip depths, make it possible to strip cable with minimal disturbance of the shielding and with no cable debris left near the strip to cause trouble.
To crimp, we use the Canare crimp dies for precise dimensional control; however, hand crimp tools loosen up and even break after thousands of cycles, so rather than mount these dies in hand-crimp tools, we use Schleuniger presses, designed expressly for crimping wire and cable connectors, to deliver the crimps. These presses are air-driven and deliver three tons of pressure per crimp, and are individually calibrated to achieve maximum pressure at die closure.
Quality cable manufacture is all about consistency and repeatability; every strip, and every crimp, needs to be as good as the one before it. With hand tools, one is always on the lookout for little problems: wire debris left on the cable, side-slit blade damage to the shielding, off-center stripping causing excess shield fragility or unintended cut-throughs, uncut shield or dielectric needing trimming, and the like. Our precision stripping and crimping equipment eliminates practically all of these considerations from the process, bringing our assembly and quality control to a higher level.