2. What are some new or developing trends in robotic-press brake technology?

Bending-machinery OEMs voice varying but optimistic comments about where press brake-robot technology trends.

Daehn, LVD: The latest generation of robotic bending cells requires no robot teaching, is automatically programmed through advanced software that generates the program for the press brake and robot, calculates all gripper positions, and considers collision detection and robot reachability—it’s basically foolproof.

Also, robot payloads are increasing, which means that the robot has higher weight capacity and better cycle times.  

The robot gripper can be the cell’s most restricting feature. Bending cells now can accommodate—and are available with—multiple gripper sizes, which makes the bending cell much more versatile. Fabricators can handle jobs from small brackets to large parts and complex forms, to work with corrugated metals, parts with lots of holes, a non-flat surface and magnetic material. 

Davis, Prima Power: The future direction is integrated, automated production lines with bending machines and an industrial robot. That makes the robotic cell more flexible. We offer offline 3D software that generates the robot code. Software with a robot automates the whole process.

Also, although automatic tool installation and warehousing are not new, the market increasingly has moved toward them. Software still is a huge point here. Not all offline software packages offer enough flexibility to allow the machine to run small batches effectively. Cobots are making great advancements today, yet software is still the limiting factor.

Alan, Bystronic: Software advancement that cuts programming times has opened the part portfolio, allowing for a larger mix to be processed with faster programming times. 

Smart-factory integration will be a key driver moving forward. Tower- feeding cut parts to the robotic press brakes provides minimal human interaction and consistent schedule times.

Langbein, Salvagnini: Automated tool setup can improve overall production efficiency greatly by increasing autonomy when producing a large variety of parts requiring specific tool setups. Vision systems, cobots and mobile robots with arms also are increasing in usage.

Nienhuis, SafanDarley: Press brake robots are increasingly affordable and user-friendly. The integration of graphical user interface-based controls, or user-interface widgets such as buttons, drop-down menus, checkboxes, text input fields, sliders, radio buttons and menus, make it easier for less-experienced personnel to operate them. 

3. What are the best applications for robotic press brakes?

Most responses revolve around volume, but opinions vary on that point.

Nienhuis, SafanDarley: The best applications for a press brake robot are high-volume production runs requiring consistent quality and precision, and operations with repetitive tasks that can be standardized.

Daehn, LVD: A large-quantity, repeat job no longer is the only application for robotic bending. Fabricators should evaluate their current part mixes and consider any future development of those mixes. This may be a challenge for job shops, but planning for the “what ifs” will help them make more educated investments that pay off. To gain the most efficiency and profitability from a robot cell, the application needs enough production volume so that the machine can run at least 2 hr. without any operator intervention. Fabricators won’t want to have to change parts and tools every 45 min. 

Davis, Prima Power: Fabricators must run a lot of similar parts for robotic brakes to really justify them. Custom and parametric parts require more complex cells; the justification starts to wane. So, fabricators should look for long-running jobs. 

While software is making advancements in low-quantity/high-variety production, the complications are tool changes, end-effector changeovers and geometry, limitations of end effectors, and collisions with the upper tooling. Part sizes that require more than one person to handle the part safely is another good application.

When fabricators have many positive and negative bends, the machine has to flip and reposition the part, which can take more time and space—that is another good application for press brake robots. Complex parts within the machine’s capacity commonly can be run much more predictably than when run by a human. 

Parts prone to sequencing mistakes are good candidates. It’s easy to mistake parts as being symmetrical that actually are asymmetrical. Knowing which side must be the against the backgauges when there’s only an 1/8-in. difference between sides can turn parts to scrap. 

More frequently we see drawings of parts calling out minimal flange lengths. This can be a problem for end-effector collisions with the tooling or ram. This is an example of an application that is not a good fit. 

Alan, Bystronic: Heavy-duty applications are the best place to start, in particular with heavy parts. Quality control will appreciate the consistent bends produced by robotic press brakes. The consistency also will assist other processes such as welding.
Langbein, Salvagnini: In our experience, the robotic press brake is best utilized as complementary to the process, such as to make tall bends that a panel bender cannot make, or to bend heavy material. Also, the robot itself can be used to perform other tasks to smooth out production flow—presenting a newly bent part for spot welding or sorting parts for downstream processes, for example. 

Robotic brakes largely shine as batch-process machines. Recent advances allow more flexibility with part sequencing due to automated setups and changeovers, but in the end, the machine will be best utilized (and correctly configured) to repeatedly run a fixed set of parts.  

4. Some fabricators purchase robotic press brakes for one contract, only to see them sit idle afterward. How can fabricators avoid having their robots become coat hangers?

Most OEMs pointed to offline programming as a means of maximizing usage of press brake robots. 

Davis, Prima Power: Unfortunately, this is a problem we sometimes see our customers face. I advise fabricators to work with their robot suppliers to leave cell designs flexible enough that they can be converted for different parts and aren’t pigeonholed into single part families. A fabricator should try to find a system that allows it to grow and add to the cell with new robot grippers, press brake tools, and the ability run longer or shorter parts in the future.

Additionally, we sometimes see that one person starts the project and gets it going, then leaves, and it ends up in the hands of someone else to finish. Robot programing is not difficult, but it does require training and time in the classroom to understand the fundamentals. Having the programming talent inhouse when it comes time to reprogram the robot to a new set of parts can make the difference. All robot integrators and OEMs have their own robot-programming software that helps the programmer create 90% of the robot code. But sometimes when a fabricator brings a new part into production, it needs someone who can actually dive into the robot programs and edit a few lines of code.

Nienhuis, SafanDarley: First, conduct a detailed parts analysis before purchasing a press brake robot to ensure a broad range of applicable parts. Then, after deciding to proceed, invest in a flexible, reconfigurable system that can adapt to various projects.
In addition, implement “lights-out” shifts to maximize utilization and productivity.

Finally, install a system specifically designed to allow the press brake to be operated manually to avoid locking all of the capital into an automated cell. Our R-brake was designed to allow for its use as a manual machine as well as an automated cell. This is the main reason why the R-brake’s robot is mounted off of the floor on a seven-axis gantry, rather than on a stand or to a track on the floor, which requires the machine to be raised a few inches. These extra inches raise the machine’s lower tools to an uncomfortable and sometimes unusable height for an operator. The situation worsens when there is a seven-axis track in front of the machine for the robot to move left and right across the front of the machine. With that setup, the entire floor space in front of the press brake is occupied with cables and hardware, making the machine unusable as a manual machine. The R-brake is equipped with a built-in manual mode activated via a switch.

Daehn, LVD: As robotic bending cells become more flexible and able to handle even small batches cost-efficiently, this becomes less of an issue. But to any shop considering robotic bending, as with any equipment investment, application and volume are key. Identify and prioritize which parts will benefit from automated bending and what production level is needed. Focus on the most frequently produced parts, and evaluate minimum and maximum part sizes, material thicknesses, part weights, and forms. 

Also, look for a robotic system that can do double duty, allowing manual operation of the press brake. 

Alan, Bystronic: Marketing the new equipment to generate more business is a great way to maximize the investment in automation. Make sure that potential clients know about an ability to adapt new technologies.

Langbein, Salvagnini: There’s more than one bending option. I recommend seriously considering all bending-machine options, including a highly automated press brake with tool changer, or a panel bender. In some cases, a panel bender may be a better choice for an application than a robotic press brake because of its speed and ability to support large pieces during bending. A panel bender can replace two or three press brakes. However, some applications cannot be performed on a panel bender, such as a part with both positive and negative bends.

A fabricator must look at the whole production flow, because very fast bending but slow feeding or unloading will create a bottleneck. 

That said, in general, a robot can be decoupled and repurposed with reasonable costs, and the press brake returned to manual operation.

5. What should fabricators consider in deciding whether to buy a robotic press brake?

Alan, Bystronic: Will the footprint of a robotic press brake make sense for shop flow? Will the initial upfront costs make sense for ROI projections? Does a job have high predictability for future production runs? 

Programming time can be lengthy with complicated parts, so longer-running jobs offer better payback. Identifying an employee to program and run the system will prevent downtime after purchase.

Daehn, LVD: They must consider three fundamental questions: Why do I want to automate? What parts do I want to automate? What’s my budget? I advise any shop considering a robotic bending cell to complete a part-study verification through its equipment supplier. Evaluate applications (part sizes, weights, volume) to define the bending cell best for the shop. The best ROI comes from striking the right balance between automation and cost per part.

Langbein, Salvagnini: Fabricators should consider the volume and variety of products. Whenever the material thickness is within 11 gauge and bending length within 13 ft., always benchmark with panel benders.

In addition, they should align their expectations for autonomy with the part. Flat parts presented to a robotic cell are easy to deal with: Simply stack the blanks straight up, take the top one and go. The challenge comes after the parts are bent. How will they be stacked? Can the robot achieve this stacking pattern? How much space must be dedicated to finished parts to obtain the required level of autonomy?

Nienhuis, SafanDarley: Fabricators should consider the specific parts and projects to be automated, then perform a cost-benefit analysis, including potential ROI and reduced labor costs. They also should make sure that they can get the support and training they will need from the OEM.

Davis, Prima Power: Fabricators must look at the overall workflow and layout of their shop and floor space to ensure an effective and convenient way to integrate the robotic cell into it. Sometimes, fabricators purchase a robotic cell without considering the footprint and the impact on their production activities. Ensuring that the robotic system has a way to load and unload workpieces is critical. 

6. What basic techniques and knowledge do personnel need to ensure successful use of robotic press brakes?

Daehn, LVD: Automated programming makes bending-cell setup and operation incredibly fast and easy. A majority of the skills and techniques that operators previously needed to know and be hands-on with directly at the press brake now are being accounted for in the offline-programming software. In turn, very little involvement is needed by the operator, so the skill level required to operate a robotic bending cell is low. It’s possible that one operator can manage multiple bending cells. However, a lot depends on the bending cell. The use of various workpiece thicknesses will require a tooling change, which in all but a fully autonomous cell is a manual operation. Successful use often can come down to workflow organization at the bending cell—setting up short-run-time jobs during strongly staffed shifts while ensuring that longer-run-time jobs are performed with less production staff on hand. 

Alan, Bystronic: With optimized software and world-class training, learning to use robotic press brakes is easier than ever. Understanding bending theory is critical. If a shop overlooks the correct tooling and bend sequence, the robot cannot save the part. Personnel should know how to use offline-programming software. Knowing the axis movements and the material flow of the cell can expedite streamlined programs that will leave production managers with smiles on their faces. 

Langbein, Salvagnini: The best personnel to operate and program the machine are the same ones who program and run parts daily on manual brakes. The sequencing and tooling setups are critical, and those operators have familiarity with the parts, so they understand process challenges.  

Nienhuis, Safan Darley: Fabricators must know well the specific parts and projects to be automated. And, they need to take advantage of OEM-provided support and training. 

Davis, Prima Power: Personnel should know how to use software that can simplify programming, as well as the production planning. A general week-long robotics class and training on offline software will be critical in the beginning stages of robot production.

They should have robot champions on the factory floor—those who will take ownership and have genuine interest in learning robotics. Invest in them, send them to appropriate training and give them all of the tools needed to do the job. Robots are complex and require some prior knowledge and troubleshooting skills. It is naive to think that an operator who has been running a press brake for only a year will automatically be the correct person to run the new robotic cell. 

A person programming a press brake robot should have a good understanding of the bending process, as well as the limitations of material-to-die ratios. It’s important that the programmer understands the limitation of the loading chamber and discharge area of material and parts. This can add quite a bit of needed space along with where the end defectors will be housed and the access to them during automatic operation. MF

See also: LVD North America, Prima Power North America, Inc., Salvagnini America, Inc., Bystronic Inc., Safan Darley

Technologies: Bending, Pressroom Automation

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