Press brakes get robot-ready

A 6-axis robot with a wide range of motion capabilities performs all part loading, bending, and unloading operations. Photo courtesy of Amada.

At last year’s FABTECH®, the show floor featured hundreds of new products and equipment, and many booths highlighted the latest in fabrication automation. One of the big trends of late is robotic press brakes. Although these systems have been around for a few years, OEMs are taking robotic bending operations to the next level, and more fabricators are integrating them on the shop floor.

"One of the reasons behind this trend is a big shortage in manpower," said Derrick Flores, assistant product manager, bending robotics, Amada America, Buena Park, Calif. "Many shops have a significant number of press brakes but are having a hard time finding operators for the presses."

Incorporating a robot on the shop floor is worth exploring and offers significant production benefits when it comes to press brake operations. But there are some things to consider before investing.

Does It Make Sense?

"If you are running the machine constantly and have the necessary volume and the right product, this can be a great option," said Mauricio Gutierrez Matta, area export manager, SafanDarley B.V., Lochem, Netherlands. Matta added that fabricators need to assess, evaluate, and identify the goal for incorporating the robot, as well as if it fits into the corporate philosophy of the company.

Incorporating a robotic press brake on the shop floor is a significant investment.

"However, there are tremendous savings time-wise, labour-wise and part-wise," said Seium Teshome, applications technical trainer, Bystronic, Elgin, Ill. "A robotic press brake can run overnight or in off-hours and ensures every part is good and the same. So yes, there is a large upfront cost, but if you have enough parts to keep that system running, it’s going to pay for itself."

Teshome added that a robotic press brake is ideal for shops that have a customer that they provide a consistent work flow and parts to, where there is a standing order of thousands of parts per month. Any large-quantity, repeat job is the perfect application.

Adjusting work flow to meet the new production demands of an automated bending system will help alleviate any bottlenecks in the process.

"Automation on the blanking side has been around for many years," said Flores. "It is natural to progress even further to increase output production. Now the trend in automation is putting the output from the blanking side back on the press brakes, dealing with the big backlog, and ensuring you can form on the press brake."

Initial Challenges

Ensuring smooth work flow, especially when it comes to automation, is not always easy. Space can be a big limitation for these large, enclosed systems. Finding a configuration that works with existing infrastructure can make all the difference.

By integrating a bending robot with Amada’s HG series press brake and automatic tool changer (ATC), fabricators can automatically bend a variety of parts with maximum accuracy (shown without safety fence). Photo courtesy of Amada.

"We’ve configured the robot to sit on top of the machine to free up space on the floor," said Matta. "But you can then also operate the machine manually, adding a level of flexibility when the volume and parts are not conducive to robotic bending."

Choosing the right robotic press brake also depends on part configuration and processing.

"One of the limiting factors is being able to hold a part," explained Flores. "When a part is difficult for an operator to handle, many customers will look to put it on a robotic press brake. Parts that have window cutouts and are flimsy will present the same challenges for robotic press brake grippers or vacuum hands as they would an operator, and the difficulty still lies in being able to manipulate the part during the bending process."

This is why many OEMs ask their customers to demonstrate the type of parts they expect to bend on this system to determine the best gripper and suction cup options for any given part. A robot is only as good as its ability to hold and move the part to the precise location for bending.

"It’s important for customers to explore how they will operate if the robot is not available or not giving the right results," said Matta. He explained that if the robot is not calibrated in the right way, it could cause even the slightest degree of deviation of the angles, which affects the bend. If you bend 1,000 parts that are all bad, the cost of scrap can be high.

"The most important thing is that operators know about robotics and programming the robot, but they also need to have knowledge of bending," said Matta. "How can they correct things if they don’t know about bending?"

Ease of Use

"Getting the product on the robotic press brake is a lot easier than what it was 10 to 15 years ago," said Flores. "The offline programming has been simplified to make it very user-friendly. The other advantage is the repeatability and consistency."

The latest robotic press brake advancements allow the operator to go from one job to the next in a matter of minutes. Also, as the manufacturing environment is constantly changing, lot sizes can be adjusted. So, instead of having to do 300 pieces, a shop can now break those lot sizes down to, say, 30 pieces in a relatively short time frame and then move on to the next job.

"It’s better suited for just-in-time production," said Flores. "For example, let’s say you have a part that is formed up; having 500 pieces formed up sitting on the floor takes up a lot of space. Now you don’t have to do that. You can break those quantities down to a more manageable number so that the floor space isn’t taken up by a formed part."

Labour Concerns

A common misconception is that adding a robot to the bending process means that you can get rid of an operator, which can be an attractive option given that it is challenging to find skilled labour and that cost of the labour is quite high. However, this is not necessarily the case.

The Mobile Bending Cell from Bystronic holds a small footprint and is detachable for automated or manual bending. Photo courtesy of Bystronic.

"Automated bending frees up the operator to do other applications or processes in the manufacturing environment," said Flores. "But you still need someone to take ownership of the equipment to make sure that the product gets on the machine and everything is running smoothly.

As previously mentioned, it’s important to ensure that an operator has knowledge of both robotics and bending, but having an intuitive system also makes it easier on the operator to keep the system running and eliminating bottlenecks.

"It seems like everybody wants something that can change tools and is simple as far as programming goes," said Teshome. "This is because a lot of shops are spending that extra time and labour trying to get the system up and running, trying to program it, making an automated system not really worth it."

OEMs have spent a great deal of time and effort ensuring that the systems are wholly integrated with programming options that seamlessly fit the robot and the press brake. The last thing any fabricator wants is to invest in a piece of equipment that is supposed to automate and streamline production, but instead slows things down or sits idle while an operator spends significant time with setup.

Programming

"In my opinion, software is the most important part of the robotic press brake," said Matta. "Ensuring that operators can easily program and make changes to the program is essential, and there have been significant improvements in this space over the last few years."

This is especially true for first-time users. Many training options are available, and starting simple is key to success.

"It’s not hard to program, but you know, really dip your toes into the water and start simple," said Teshome. "Because it’s all offline programming, you can jump back into the office and really explore the software in terms of more complex bend sequences once you’ve established some of the basics."

The offline programming makes it easy for an operator to generate, test, and execute the motions of the robot. Flores explained that an operator can simulate the path in a 3D environment to see what it will look like on the press brake before even stepping foot near the machine. Once it’s been approved, the program is ready for production and the operator can move on to developing other programs while the machine is bending.

Robotic Press Brake Technology

"I think there’s always going to be a place for a stand-alone press brake," said Flores. "Whether it’s prototyping or an intricate part, not all jobs lend well to the automated bending process. But robotic press brakes have gained significant momentum over the last few years."

According to sources, the benefits of incorporating a robotic press brake include enhanced accuracy, improved repeatability, and significant time savings. One of its limitations is a lack of flexibility, but as more and more shops move to automation, this will become less of a concern.

Multiple part stacks can be loaded with no worry—the robot will do a search routine to determine the height of the stack and when to move to the next. Photo courtesy of Bystronic.

"Going forward, we envision automation not just on your press brake or your laser, but all throughout the factory," said Teshome. "Incorporating robotics on a press brake is just the beginning of this."

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