One might think that offloading parts would be a good way to lose new people in a hurry. But that doesn’t happen at Cupples’, mainly because operators learn the importance of a smooth offload process. If operators can remove, stack, and send parts downstream to the next operation quickly, they know that all the operational variables around them are working as they should. Each machine has a swing-arm loader with extended reach. And at every machine, people can access the shuttle table on both sides, able to remove and sort parts as quickly as possible.
Shaking and breaking is a rarity. “We don’t like to tab [parts into nests],” Cupples said, adding that programmers pay careful attention to part orientation and a machine’s slat configuration for consistent cut-part support, sometimes changing a slat configuration to suit the day’s mix of parts.
In any situation, manual or automated, the shake-and-break slows throughput, and for most people it’s a thankless job. If rookies at Cupples’ spent their days shaking and breaking, they probably wouldn’t stay at the company for long.
They also wouldn’t stay long if they worked amid chaos, scurrying from shuttle table to shuttle table, sweating profusely to remove parts before the laser finishes cutting the next sheet. But they don’t scurry. After the laser finishes its cycle, the dual-shuttle system removes the cut sheet and replaces it with a fresh one. Rookies unload the pieces in an orderly fashion, and they chat with veterans while doing so to learn how and why the operation works so smoothly.
For instance, they learn that though the occasional part might need to go through the part leveler, they don’t need to go through flat-part deburring. “Our general rule is we want less than a 0.005-in. burr on the edge, which industry standards say is essentially no burr at all,” Cupples said. “So if we can’t achieve a burr less than 0.005 in. consistently with a fiber laser, we use our CO2 lasers. Still, we do production cutting with 10 mm and thinner with nitrogen, and 99% of that is cut with the fiber laser.”
Another example: A veteran sorting parts might point out two narrow parts that will be left- and right-hand pieces that will be formed into narrow channels. They’re nested adjacent to each other but mirrored so that edge-geometry attributes are opposite each other. The rookie recalls that material yield is incredibly important, and yet arranging these parts in this fashion seems to leave a wider web section. He brings this up to the experienced veteran nearby, and the veteran explains about the release of residual stress after cutting, as well as the nature of forming tolerances on the press brake. The long, narrow blank is bowed ever so slightly, because the laser released stress that was trapped in the sheet.