From a distance, the antennas atop a cell-phone tower don’t look that big. In fact, those “little” white boxes are 4 to 12 feet long, 2 feet wide and 1 foot deep. These boxes may be packed with sophisticated electronics—but it’s all held in place with screws. A typical antenna might contain hundreds of screws in more than a dozen different sizes and types.
Such was the challenge presented recently to the ASG Division of Jergens Inc. The application posed several problems. The first was to design equipment that could access every location in the assembly. Another was to ensure that the large, expensive and somewhat fragile electronic subassemblies were not damaged during installation of the screws. A final challenge was error-proofing. With so many screws to install, the antenna manufacturer needed a way to ensure that every screw was installed.