“Using collaborative robots to tend resistive welders? To the best of our knowledge, this was not something anyone in the industry had done before,” says Juan Rodriguez, Director of Automation with Crum Manufacturing, a Certified Systems Integrator of Universal Robots.
He was working with T&W Stamping in Youngstown, Ohio, a contract manufacturer primarily for the heavy-duty truck market who was in need of a reliable automation solution. “We had just received a contract from a large customer of ours to manufacture powertrain brackets,” says Craig Sivak, Executive Vice President & General Manager, T&W Stamping. “Volume on it wasn’t huge—about 40,000 parts per year—but each part has eight weld nuts, so that’s 320,000 welds that we would otherwise have to do manually.” Sivak and his team decided to investigate whether collaborative robots could handle the task. “With a cobot, we could keep our existing layout as we didn’t need additional guarding around the cobot due to its built-in safety system,” he says.
While it is common for large industrial robots to perform resistive welding, Rodriguez explains why this is not an application that small collaborative robots have historically handled. “Resistive welders set off an EMP (eletro-magnetic pulse) that blanks out any kind of electronics in a certain radius. That’s not an
issue with traditional robots with big C-clamp end-of-arm tools where the robot is extremely far away from the point of strike,” he says. “But with a small cobot that you try to fit nicely into an existing cell? That’s a very different story.”