How one fabricator maintains quality in bending

Figure 1
Experienced press brake operators are not easily found, but when they come to work at DeWys Manufacturing, they tend to progress quickly through the company’s training.

Does any of this sound familiar? Quality personnel are running from one end of the facility to the other to check on certain parts, often leaving someone in the bending department waiting around until the part is given the OK. A veteran press brake operator is able to produce a quality first piece and proceed efficiently with the job, while a less experienced operator has scrapped three parts trying to figure out how the multibend sequence works. No one is bending parts—high quality or otherwise—because the operator is searching for tooling.

Unfortunately, many fabricators are probably nodding their heads while reading this. DeWys Manufacturing, Marne, Mich., occasionally experienced some of that before it got serious about lean manufacturing in the early 2000s and launched DeWys University, a dedicated training space built four years ago in the rear of the facility. The university offers basic training and continuous learning opportunities for its employees. The fabricator also made some key investments that helped to raise its capabilities.

The result has been increases in productivity and quality, the latter of which happened without a stand-alone quality department or individuals with the title of quality inspector. Many factors are contributing to this environment in which quality parts consistently come off the press brakes. Following are five of the largest contributors.

1. Provide Proper Training

The press brake course at DeWys University is six weeks long. It involves classroom coursework and on-the-floor, hands-on training as well. As the course progresses, trainees find themselves on the floor much more than they are in the classroom. Some people with prior experience (see Figure 1) might complete the training and start working more independently than their less experienced peers, according to Kris Cousineau, DeWys Manufacturing’s press brake trainer.

“It’s nice to have an experienced operator,” Cousineau said, “but we definitely see a lot of people that have never seen a press brake before or have never used a caliper to measure something. It takes a little bit longer to go through the training to learn how to measure the parts and the tool used to do the measuring.”

The training covers basics such as blueprint reading in addition to press brake operation and an overview of how metal changes as it is being formed. The training does not rely solely on information provided by the machine tool builder, a consultant, or vocational educational institution. Elements are taken from those sources and enhanced with DeWys Manufacturing’s own experiences. Students are not only getting manufacturing training, but also an education in the way that things are done at DeWys Manufacturing.

A big part of that is exposure to lean manufacturing principles and how they influence activities on the shop floor.

“Recently we provided training in the eight deadly wastes, 6S, and process audits, which verifies that they are doing what they are saying they are doing, such as checking the parts,” said Bob Miller, a continuous improvement leader at DeWys Manufacturing. “We also get them to fill out the FIT report, which is a continuous improvement tool, where they scan in their jobs and provide comments, such as ‘If we form this bend first and this bend last, then we will make this part faster.’

“We’re teaching them all of this,” Miller added.

At about the two-month point, the participants in the press brake training class start to work more independently. In the ensuing months, they continue to learn, but still run into obstacles, which means the press brake trainer keeps a close eye on them as they take on bending jobs, according to Cousineau.

Figure 2
A press brake operator doesn’t have to try out a part to get down the bend sequence. The monitor provides the guidance necessary to get a first piece right on the first attempt.

Typically at the six-month mark, the press brake operator shows fewer signs of being new to the process. Cousineau said they actually start to ask questions about bend sequence or part handling that a seasoned operator might ask. They also are very much aware of the stakes at this point.

“We don’t build extra pieces,” said Chris Hawkins, DeWys Manufacturing’s operations manager. “If we do, it’s very rarely. They have that pressure on them.

“They get exactly what they need for the job,” Hawkins continued. “If they make a mistake, we have to go back and cut more.”

2. Standardize Technology

Simply put, a fabricator is able to maximize efficiency and quality if press brake operators use the same tooling, run the same machine, and interact with the same software. In the land of misfit machine tools, which pretty much represents every fabricating operation in existence, this can be an insurmountable obstacle for fabricators looking to streamline bending operations.

DeWys Manufacturing didn’t want to follow that plan when it came to upgrading its bending capabilities. Following the idea of “standardization,” a part of 6S training, it decided to invest in one type of press brake as it planned to upgrade its bending capabilities four years ago. After taking a look at several manufacturers, it purchased six Bystronic Xpert 150-ton hydraulic press brakes.

Of course, such a purchase is out of reach for many smaller job shops, but it has paid off in terms of the company’s ability to stay on top of increasing business over the years. More specifically, the brakes are keeping up with two fiber laser cutting machines running 24/7. Hawkins said that about 90 percent of the company’s press brake work runs through those six machines.

Life is a lot simpler with common bending technology. The company’s operators now use the same tools and follow the same programs. Certain operators aren’t limited to a specific machine because he is the only one who knows how to run it efficiently.

“It can be hard if you buy a press brake one year and buy another two years later. They are different,” Hawkins said. “Manufacturers are always improving and changing. You might be dealing with two different machines even though they may be from the same manufacturer because they have different bells and whistles.”

The modern aspects of the new press brakes have helped quality efforts as well. All of them have dynamic crowning, which ensures that the ram load is evenly distributed along the workpiece, regardless of the inconsistencies in the metal. The monitors provide step-by-step visual instructions for operators that may need a visual clue as to how a multi-bend sequence should run (see Figure 2). That comes in handy for parts that require more than one or two bends. It shows the operator how to put the part in, turn it, and flip it over. Everything is replicated in a virtual model on the monitor.

While he didn’t have exact statistics, Hawkins said that DeWys Manufacturing saw tremendous drops in the amount of rework and rejected parts when the new press brakes went online. He said quality rates continue to incrementally improve year after year as new operators become more comfortable with the equipment.

Figure 3
Each press brake has its own set of tooling, kept on a color-coded rack that denotes what tooling belongs to what press brake.

That’s good news for a fabricator that bends 200 to 250 new parts on the press brakes every month.

But perhaps the most dramatic change for the company has been the shift to offline programming of the press brakes. With one software required to run the six press brakes, one programmer is dedicated to the task. All bending jobs go through that individual. (In fact, that one programmer is also responsible for programming jobs for the laser cutting machines, turret punch presses, and even hardware-insertion machines.)

“Software and offline programming have made all the difference in the world,” Cousineau said. “That cut our setup time in half.”

When operators don’t have to worry about programming jobs, they can focus on producing quality parts.

3. Invest in the Employee

Another thing that DeWys Manufacturing did when it purchased the new press brakes was to buy six complete sets of Wilson Tool press brake tooling, one for each press brake (see Figure 3). Operators would no longer have to go searching for the right tooling to run the job that was slated next for the press brake.

“They used to have to get their own tooling, and nothing was there for them [before the new press brakes were installed]. They just knew what to do,” Cousineau said. “Now it’s all there for them.”

Cousineau said the tooling was part of the wow factor that helped to win over the press brake operators, experienced and unexperienced. They were being asked to learn a whole new way to bend parts, but they were going to be given the tools to make the learning curve as smooth as possible.

On a smaller scale, the company also provides complete toolsets kept in shadow boxes near each press brake (see Figure 4). It’s another symbol for the operators to recognize that they have the best tools available to produce quality work.

4. Find the Right Person for the Job

Just having a warm body to stand in front of a press brake is not part of DeWys Manufacturing’s master plan. It wants to have employees who can grasp the concepts and understand the commitment necessary to make a real impact in the bending department. To help achieve that goal, management looks for the right candidates for the job.

A mechanical aptitude test has done wonders to help find those individuals, Cousineau said. This test was something that he and another co-worker found on the Internet and then slightly adjusted to include some questions that were more tailored to a metal fabricating environment. For example, one of the test sections might refer to a picture of a pulley and ask the test-taker to figure out what might happen if certain actions were applied to the pulley system.

Figure 4
The basic tools for quality checks are kept in shadow boxes near each of the six new press brakes. The missing tools are in use and should be returned at the end of the shift.

The 85 to 90 percent that do well on that mechanical reasoning test tend to be able to handle life in front of the brake, Hawkins said.

Cousineau added they often throw out another question during the interviewing and testing process to see if the job candidate might be a good fit for the press brake: Do you play video games?

“It’s amazing how fast that they can pick up on that controller if they are playing with a computer all the time,” Cousineau said.

Again, operators who are not intimidated by the equipment and are comfortable with the controller can focus on the bending job and worry about little else (see Figure 5).

5. Democratize the Quality Effort

Above all else, DeWys Manufacturing decided that if it wanted to make quality parts, it should make everyone quality inspectors.

“We don’t have quality folks running around checking parts. All of our people are checking their own product in-process,” Hawkins said.

Each operator does a first-piece check with the quality tools situated near their own press brake. The check is made against specifications that are included with the traveler that is matched with each production job. Until an operator reaches the supervisor level, he or she is required to have Cousineau or some other qualified operator to sign off on that check. Miller said weekly audits are done to ensure that these steps are followed on a routine basis.

Most of the dimensions that are checked are based on customer input. The goal is to have the check done quickly, so that parts can continue through one of the six value streams (which are defined as similar types of product flowing through unique routes, such as parts that require bending, hardware insertion, and painting, parts that need bending and welding but no painting, and so forth).

The signoffs are necessary, according to Cousineau, because less experienced operators don’t have much experience measuring parts. Some have never seen a caliper and really have no idea how to use a protractor. In the end, however, the operators, helped by training and technology, get to the point where they are able to ensure parts remain within tolerances, typically within ± 0.015 in.

“Through the training packages that we have created,” Hawkins said, “Kris and others will train our people, give them the skill set so that they know what to check and what to monitor so that they are monitoring throughout the run. Production flow keeps going.”

Figure 5
Visual communication is a key component of lean manufacturing principles. This chart indicates the success that Value Stream A is enjoying while it is bending parts for downstream processing.

The Work Continues

Of the roughly 20 press brake operators DeWys has, Hawkins estimated about half have more than 10 years’ experience, while the other half has fewer than three years’ experience. That makes for a nice mix of workers who have one very important thing in common: bending parts.

Cousineau said that with headaches such as looking for the right tooling and programming jobs taken away from the operators, they can spend more time interacting with each other, lending expertise to less experienced peers when necessary and even providing feedback to the equipment programmer who might have created a bend sequence that just doesn’t work. That’s the interaction that ultimately leads to continuous improvement.

Technically, continuing those process improvements is reflected in Miller’s title, but he’s the first to say that when lean manufacturing is working, the shop floor personnel are doing the work to make processes leaner.

“A press brake doesn’t run unless someone is standing there,” Miller said. “The biggest thing is finding out what is pulling them off of the machine.”

That’s where the operator feedback is important. Maybe it’s too much paperwork. As a result, DeWys Manufacturing tries to have bar code scanners everywhere they may be needed. Maybe the operator has to go get parts. Miller said that they are giving a lot of thought to how the parts are brought to the press brakes (see Figure 6).

“The operators are walking and talking about these processes to make them better,” Hawkins said.

Success in producing quality fabricated parts is never a one-man show.

Figure 6
Blanks currently arrive at the press brake department on conveyors and then are transferred to carts. Continuous improvement efforts will entail taking a closer look at this material flow to see if something else can be done to ensure operators don’t spend too much time handling material.