People depend on Mike Rybak. Rybak is a tool crib technician at telecom equipment maker ADC Telecommunications’ sheet metal shop in Shakopee, Minn. His job is to ensure one thing: that quality tools are available when machine operators need them. Getting that job done means constantly evaluating the quality of the shop’s approximately 750 punches, shapes and forms and rectifying the situation if they don’t pass muster. Last year ADC purchased its second industrial punch and die grinder (PDG) from DCM Tech Inc. about seven years after purchasing its first one.
ADC has 13 punch presses running two eight-hour shifts, five days a week, punching parts out of all kinds of material: aluminum, steel, copper, brass and even plastic, in thicknesses from 0.0060 in. to 3/16 in. With that volume of tool use, the onus is on the technicians in the tool crib to help keep errors, such as tool deflection, from decreasing the quality of the components coming off the turrets. And that means maintaining the tooling. Sharp edges are important "We’re running a lot of tools, and we need to do them faster and more efficiently," Rybak says. "It [the PDG] just helps my whole process. In a lot of shops...the operators have to find their own tooling, and when they get it, they have to look to see if it’s sharp. If it’s not, they have to do whatever process they do to get it sharpened. "We check all the tooling when it comes back from the machine. If it’s sharp, it goes in the drawer. If it’s not sharp, it goes back to the grinder," he adds. Before ADC decided to purchase its first PDG several years ago he had to hand-grind dull tooling on an old homemade grinder, Rybak recalls. Knowing that the old machine wasn’t giving him the flatness he wanted, he began to investigate some options and learned of DCM, which was fairly close geographically but unknown to Rybak. That soon changed as Rybak got permission to test some of his parts on a DCM machine in nearby Redwing, Minn. "I brought some of my easy stuff; I brought some tough stuff I knew that I have problems with," Rybak recalls. "I sat there and played with it for half an hour, and that thing was exactly what I was looking for." The old machine could clamp a piece of tooling in a chuck and spin it; otherwise, it bore no resemblance to the automatic-feed grinding that ADC now has the PDG doing eight hours a day. "I had to sit there and physically run the tool across the grinder," Rybak says. "The tool was done when I stopped grinding it. It was a completely labor-intensive process."
Set it and forget it Not anymore. The PDG combines universal fixturing and an interchangeable, three-jaw chuck with a PLC auto-feed control, allowing Rybak to clamp in a punch and then occupy himself with other tasks while the machine is working. "This is ‘set it and forget it,’" Rybak says. "It runs, and when it’s done, it shuts off by itself. You don’t have to baby-sit it and make sure it’s doing what it’s supposed to do. "The efficiency of the machine is better than what we had before. It was harder to keep a true, flat surface on the old system. The flatter you can grind a tool, the more efficiently you’re going to punch." ADC machine operators stop by the tool crib all day long looking for tooling, which Rybak stores by part number. It’s the tool crib’s job to make sure they don’t have to wait around for the proper tools to do their jobs. "We pre-issue everything out to the machine," Rybak says. "When the operators finish, they grab the tooling, they load it and they’re running. They don’t have to search for tools." And when an operator gets a tool, Rybak wants it sharp. "We take it to the Nth degree," he says. "We don’t let an edge go away. We’ll take it and dress five thousandths off it to keep it in tip-top shape." That job is easier with automatic grinding, but the automation alone doesn’t do it. DCM has coupled its automation with polycrystalline cubic boron nitride (PCBN) grinding wheels, which DCM has found to be the best medium for automatic grinding. "We offer that because the wheel is very predictable in the way it works," says Skip Green of DCM’s technical sales department. "It does not require dressing. You have a very consistent amount of stock removal. We picked a wheel that will self-dress and will work with an auto-feed grinder. "We tried using conventional abrasives, and they made it so that the auto-feed was almost unusable because the wheel would load up in the middle of a grinding cycle, and then you’d start burning tools. There are people who use manual grinders, and they’re constantly dressing and burning tools, and we just wanted to get away from that." The PDG also features universal fixturing with an interchangeable three-jaw chuck and permanent magnet. Rybak says the newer PDG works like a centerless grinder, providing constant contact on the tool being ground with the coolant flood. "It’s very convenient," he says. "It’s a really nice feature." In addition, the PDG uses a 15-gallon recirculating coolant system with basket-style filtration. "It’s a self-contained unit," he says. "The chemical is all right there. You run power to it, put water in it, add lubricant and you’re running." Rybak says that with 13 turrets, including one 48-station and one 42-station machine, ADC probably runs through a little bit more money on the tooling side than a lot of shops--making an efficient method of tool reconditioning all the more important. So for what he is getting out of the PDG machines and the time he is saving, "I think it has more than easily paid for itself many times over," he says. Mid- to high-volume operations like ADC are what the PDG was designed for, Green says. However, smaller shops that deal in shorter runs of higher-end products also have an interest in maintaining their tooling. "They don’t want to distort the part," Green says of those specialty shops. "They want nice, crisp cuts. They don’t want to have some guy going in there with a die grinder and having to deburr everything." Rybak says it is difficult to put a number on his efficiency improvements, except to say the PDG has made it "many times better." "There’s no other process that I’ve found that is as fast and easy and convenient as this," he says. FFJ
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