Peter Zelinski has been a writer and editor for Modern Machine Shop for more than a decade. One of the aspects of this work that he enjoys the most is visiting machining facilities to learn about the manufacturing technology, systems and strategies they have adopted, and the successes they’ve realized as a result. Pete earned his degree in mechanical engineering from the University of Cincinnati, and he first learned about machining by running and programming machine tools in a metalworking laboratory within GE Aircraft Engines. Follow Pete on Twitter at Z_Axis_MMS.
Additive manfuacturing can make a part as if from nothing. Without tooling and without a pattern, the machine can generate a precise, solid, intricate form. But is “nothing” really the best starting point?
DM3D, a Michigan-based manufacturer of production AM parts, has recently been advancing a different idea. In some cases, rather than using AM to grow the complete part, the far more efficient use of additive is to start with a basic workpiece and grow the necessary details onto this part. “TransFormAM” is the company’s brand name for this idea.
The part above provides an illustration. This 25-inch diameter Inconel 625 component represents a jet engine casing. For a part like this to be grown entirely through AM would take something like 500 hours, says DM3D. An alternative is to begin with a cylindrical blank of material produced through forging or roll forming. When the company made the part this way, using AM just to add features and details, the additive cycle time was only 21 hours.
Automation is a broad topic that we often picture narrowly. Say “automation,” and we tend to picture robots—even though the range of what automation might involve includes these devices and more. Similarly, we tend to imagine that automation refers to technology taking the place of people. In fact, productive uses of automation in manufacturing often involve people and technology working in parallel to complement one another. I had a chance to talk about automation—its importance, its value, and why it is succeeding now—in this video.
A collaborative robot (green) ran alongside a demonstration of a fenceless robot at the automation integrator’s event. A fenceless robot uses sensors to halt the robot’s operation if a person comes too close.
One of the most significant recent developments in industrial robotics is the commercial introduction of collaborative robots. A collaborative robot (sometimes shortened to “cobot”) is a force-limited, contact-sensing robot that is safe to apply in the near and immediate presence of a human being, without guarding, because the robot will stop if it contacts a person and it will not move with enough energy to injure a person if it does make contact.
Last week, robotics integrator Acieta hosted a day-long event at its Council Bluffs, Iowa, headquarters focused on collaborative robots. Speakers represented not just Acieta but also ATI Industrial Automation, FANUC America, Schunk, Distefano Tool & Manufacturing Co. and the Robotics Industry Association.
Acieta founder John Burg described to me why it was important for the company to host this event: Manufacturers are rightly impressed with the possibilities of collaborative robots, he says, and many engineers are being urged by their management to explore a collaborative automation solution. Yet many of those applications simply do not lend themselves to a robot of this type.
Here is a recent example of an application he has seen in which a collaborative robot makes sense: A basket that is sent into heat treatment is manually loaded with parts. Various baskets have warped differently after many heat-treat cycles, so automated loading of the baskets is problematic. However, a robot lifts the basket of parts once it is full. Here, collaborative technology makes it safe and simple for a person and a robot to work on the task together.
But in a different application in which the user was initially focused on a collaborative robot, Mr. Burg says this user needed to achieve a narrow cycle time target for the productivity of the robot loading. Part of the way collaborative robots protect against injury is by moving slower than other robots have the capability of doing. And as it happened, this limited speed proved too slow to meet the needs of that application.
A presentation at the event by Schunk Regional Sales Manager Larry Bergren gave attention to another straightforward consideration relevant to collaborative robots. Namely, the gripper is not necessarily collaborative. A standard robot gripper does not offer the same responsiveness to contact that the robot itself does, he says.
Schunk has such a gripper under development and plans to introduce it soon, but the product is not ready for market yet. For now, he says, the company will offer a selection of grippers to complement collaborative robots. Grippers in this category can limit grip force, are covered in soft material and designed to limit sharp edges and pinch points, and feature a light indicating when the gripper is about to move. All of these features enable safe use near humans until the fully collaborative gripper comes.
In a different presentation, Claude Dinsmoor, general manager for material handling segment robotics with FANUC America, described some of the background of collaborative robotics as well as his view of a possible future.
This type of robot became viable for widespread industrial application in part because of an ISO standard, he says. A standard related to the safe application of industrial robots was revised in 2012 to address power- and force-limited robots. Guidance added later addressed the maximum force that different parts of the human body could acceptably experience in a contact with a moving robot. Those parameters enabled the development and introduction of robots that could be assured of not causing injury in moving contact. The result is a robot operating under very different rules than conventional robots, he says, because the latter are almost always kept segregated from humans. To note the difference, FANUC departed from its trademark yellow color in order to make its collaborative robots green.
A factor he noted is the planning this robot might create the need for, specifically because of the breadth of interaction it might have with people. The robot itself is safe to operate near a person, but how many people in the organization will have access to it? In a wide-open cell, any employee walking through the shop might step close to the robot. The entire environment this robot figures into potentially has to be evaluated for safety with this possibility in mind.
Indeed, that consideration is partly why achieving unguarded safety through collaborative robots might ultimately prove to be simply an interim step, he says. Today, a robot limited in speed and payload presents the most effective option for using robots near people. But another option already in use involves applying sensors to allow regular robots to be “fenceless.” The robot controlled in this way will slow when a person comes near, and it will stop when a person comes very close. In the future, continued advances in sensing technology might lead to even more effective fenceless robots that are safely capable of fast and highly productive use near people.
Collaborative robots are force-sensing robots that are safe to operate near people. These machines ran in unguarded demonstrations at the Acieta event focused on this technology.
Manufacturers now succeeding with additive manufacturing have begun to see what its ultimate impact might be. I had a chance to speak to that here. This video summarizes some of the ideas and promises related to AM that were not clear at first, but now are becoming apparent.
“Your comment that the Japanese do not listen to music while working reminded me of a video that we show in our shop to new employees. Despite what people think about their ability to multitask, the human mind can really only focus on one task at a time. You can either listen to music or work with your hands. Take a few minutes to watch this YouTube video [embedded above].”
He went on to say: “I have been showing this video for a couple of years. The reason: our millennials. I have watched our youngest employees bouncing to the music in their headphones while either punching offsets into the controls of our very expensive CNC production equipment or ensuring the quality of our customers’ parts. We want them to enjoy their time at work, but they also need to understand their responsibility to our stakeholders to be productive in an extremely competitive global market.
“I banned the headphones. They are a distraction as well as a safety concern. While I have not banned cell phone use in the building, I have stressed that its use should be appropriate to work. Focus!
“That focus is important. We stress to the staff that anyone with several million dollars can buy every piece of equipment we own. There is nothing unique about the Tornos Deco, Tsugami, Index, Euroturn or Miyano equipment that we own. The only competitive advantage that we have is each team member’s brain working in conjunction with the brains of their co-workers.”