The curiously high quantity of gear makers in Roscoe, IL, is related to the past peak of the machine tool boom in nearby Rockford. As is the case in many other industries, the gear making market has changed over the years, leading companies to change their approaches to offset the decline in local machine tool building. Forest City Gear decided to "…make the very best fine and medium coarse pitch gears in the world," according to CEO Fred Young. Manufacturing the best of anything typically requires the best equipment to stay competitive. Forest City employs four Gleason shapers, two Samputensili grinders, and a Hoefler gear grinder. The common element between all of those machines is control in the form of Siemens Sinumerik 840D CNC controllers with specialized gear software.
Typically, the CNC is used for all axis, rotary and spindle movements and the machine operators particularly appreciate the multiple standard cycles for cutting with degressive feeds, increasing speeds plus special cycles for gear tooth removal and reversing directions to improve finish or reduce cutter wear.
"I've used all the brands of controls we have here. . .and for many jobs, no other control can do what the Siemens 840D can do," says Kevin Chatfield, a longtime Forest City Gear employee with 20 years' CNC machine experience, who works with the Samputensili grinders. "One example would be the internal, external and form-grinding I do on the Samputensili machine. If the other controls could perform these operations at all, which is doubtful, it would be a very slow process."
Forest City produces gears from a variety of both standard and exotic materials.
"These machine tools produce our most complex parts, including helical splines and internal gears most other shops simply cannot or will not make," says CEO Young. "The cycle and program read times on the Siemens controls are critical to our production work, plus these are the most expensive machines in the shop, so their run-time cost is the highest." He adds, "Most of our jobs, though not all, here are short runs on very expensive materials. If the machine takes too long to complete the first part or has repeat rejects, we lose money—it's that simple. I'm proud to say that neither our operators nor our production supervisors allow that to happen. And the controls on the machines are a big reason why we stay so successful in achieving that accuracy and consistently good part production at Forest City Gear."
