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Industrial Automation and Motion Control Blog | The Knotts Company


Posted by Mark Howe on February 20, 2018 08:07 AM

This post is brought to you by Universal Robots.

Once companies automate processes with robotics, they don’t look back. They quickly learn to depend on the consistent, reliable output, day after day, and year after year. But that means dependability is more important than ever. Companies simply can’t afford downtime that will impact productivity and profitability. One of the less-known benefits of collaborative robots is their nearly maintenance-free operation and long-term reliability. That’s true even in the toughest, dirtiest environments that would put any human worker to the test.

Nick A, automation engineer with a UR distributor, explains that the company’s experience with the robots’ durability is common. “We very often see the robots operate in harsh environments, taking over jobs that humans don’t want to perform,” he says. “Many think of cobots as being fragile but the opposite is true: this is an extremely durable robot. It’s sealed against dust, rated for high temperatures, and works just as well in extreme environments as in a cleanroom.”

Hot, dusty environment doesn't slow down plasma spray robot.

Aircraft Tooling (ATI), a Texas-based repair center for the aviation industry and a UR distributor customer, was surprised to find that UR cobots could withstand the high temperatures and harsh environment of its metal powder and plasma spray processes. “It simply looked too clean,” thought Juan Puente while he was researching the UR robot arm. Puente is ATI’s thermal spray supervisor who was looking to automate repair tasks involving new high-velocity oxygen fuel (HVOF) and plasma spray on parts for the aviation industry. He loved the UR robot’s significant cost savings over traditional robots, as well as its portability, safety, and ease of use. But he was worried about how reliably the robot would operate in the spray booth’s extremely hot and dusty environment.

“I actually thought the robot wouldn’t stand it. Some of these powder coatings are tungsten carbide, which is a hard metal coating. If it seeps into the bearings of the robot, we were afraid it would destroy them,” he explains. But ATI opened up the seals on the UR10 after three years and found the bearings intact, with no evidence of particles inside. Puente was also concerned about recoil from the spray gun, worried that it would trip the robot or interfere with the servo capabilities. “We went as high as the pressures would take to make it bounce, and it wouldn’t do it. The robot simply stayed in position,” he recounts. In three years of operation, the cobots have operated consistently without breakdown or service requirements.

ATI was surprised to find that no preventive maintenance was required with the UR robots. “All we do is dust the robot arm off and keep on going,” says Puente, adding that he did not have to pay for a licensing or service agreement. “That was really unusual compared to other solutions we looked at. With the UR robot, everything was included in the purchase price.”

One million parts processed in a year, with little to no maintenance

Massachusetts-based Tegra Medical has multiple UR robots tending machines in its medical device manufacturing operation. The robots easily meet the demanding repeatability and accuracy requirements, and require minimal maintenance—even after turning out a million parts from one robot cell in less than a year.

“The accuracy and repeatability over time was a big concern for us,” says Hal Blenkhorn, Director of Engineering at Tegra Medical. “We were apprehensive, questioning whether we could put the robot through this kind of duty cycle in a high-volume cell and get year-after-year repeatability. We spot-check every few months to make sure the axes are performing, and it is as good today as a year ago when we turned the cell on.”

His colleague, Paul Quitzau, also appreciates the robots’ modular design, which makes any necessary repairs easy. Spare parts are held at their distributor’s facility or at a local UR office that can overnight parts if need be. “We didn’t have such a great experience with some of our other robotic applications. If a robot went down, it was time troubleshooting over the phone. It was a week or two of downtime waiting to get parts in, followed by an external engineer having to come in and install and requalify it. With the UR robot’s modular design, we can install parts ourselves without being handcuffed to an integrator. We think this is a better way to go for high-volume cells.”

Topics: Universal Robots