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The solution
The order Toolcraft had to complete was a multi-threaded part for a medical device that needed to be loaded into a three-step CNC machining operation. Toolcraft discussed the challenge with Rapid Design Solutions, a Certified Systems Integrator of Universal Robots. “When you’re doing multi-op precision machining, the accuracy requirements go way up,” says owner Troy Ojalehto, emphasizing the increased accuracy of Universal Robots’ e-Series line of cobots. “When we heard that the repeatability of the UR5e was down to 30 microns, we were very excited,” he says. “That really competes in the same space as traditional industrial robots, so that was huge for us. I have not seen other cobots handling this level of precision with multi-op parts like this, with raw stock going in and completed precision parts coming out.”
Half a year into deploying the UR5e, Toolcraft’s Wittenberg is quick to list the results. “Some of the benefits we’ve seen right off were a significant production increase,” he says. “We were able to staff that third shift and went from producing 255 parts a week to 370 parts per week. Along with that, we’re able to finish our year’s production seven weeks sooner, thus freeing up that machine to produce parts on other jobs.” He adds that costs have decreased by 23 percent, which means that Toolcraft is looking at an ROI on the UR5e at around 12 months. “We’re going to be able to be more competitive on a lot of the long-term work that we have.”
Acts like a human operator
Another new feature in Universal Robots’ new flagship line of cobots is force feedback in all the joints, which is key to making the part fit tightly into the CNC fixturing. “Using the force motion with freedom in the X,Y and rotational Z axes, we can force the part in there, and wiggle it, and program that compliance very easily to enable basically a human touch with the robot.
The machining cycle lasts 56 minutes with the UR5e only busy tending parts for 6 minutes of this. “The rest of the time, the cobot was just hanging out waiting for the next cycle. We wanted to keep it busy,” says Wittenberg, explaining how the company added a part rinsing and cleaning station. As the UR5e takes the machined part out of the CNC, the cobot now dips the part into a rinsing solution then passes it through an air jet before finally placing the washed and dried part on a rack for shipping. The machine shop was also able to easily control the pneumatic fixture and door actuators through the UR5e I/O interfaces. “This greatly reduces the need for CNC wiring and preserves all the CNC’s standard safety functions,” explains Ojalehto.
While Toolcraft enlisted the assistance of a system integrator to get the initial application up and running, the machine shop was able to program and install the rinsing and drying station on their own. “What really enabled us to do this was all the free online support Universal Robots gives you,” says Wittenberg. “After our automation engineer took the online UR Academy, he spent a few hours with the integrator and was able to add that station to the cobot cycle with no external help otherwise.”
At first, Wittenberg feared that production would go down during the programming phase of the rinsing station as the UR5e would then be unable to handle its regular machine tending duties. The Toolcraft team discovered, however, that they could simply use Universal Robots’ simulator and program almost the entire addition to the cycle offline while the cobot kept working.
UR+ gripper speeds up integration
Another UR initiative that sped up integration is the UR+ program that certifies robot peripherals, such as grippers, vision systems, software and other accessories to work seamlessly with UR cobots. “For this application, we chose a Pneu-Connect pneumatic gripper,” says Ojalehto from Rapid Design Solutions. “A big factor is that it’s UR+ certified, which means it works with Universal right out of the box with all gripper software integrated directly on the UR teach pendant, eliminating the need to do any script coding.”
One cobot a year, automating horizontal mill is next
With the first successful cobot installation under its belt, Toolcraft is now planning to install one cobot per year. “The fact that our own automation engineer is now able to go in and troubleshoot anything that comes up is going to be key in us meeting this goal,” says Wittenberg, explaining that the next task to be automated on the shop floor is tending a horizontal mill. “That’s a potential challenge because of the mills using rotary tombstones that are swapped in and out of the milling machine, which creates some difficulties with fixturing. But we’re confident we can solve those using a Universal Robot and some innovation in fixturing.”
UR cobot models: UR5e
UR+ products used: PHD Pneu Connect gripper
