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The Measure Of Efficiency

February 2012

Increasing productivity through cutting-edge bending

Shigeo Shingo, one of the leading experts on the Toyota Production System, observed that “it’s only the last turn of a bolt that tightens it – the rest is just wasted movement.” David Prokop, co-owner of International Technologies Inc., believes that Shingo’s philosophies are key to maintaining U.S. competitiveness. He cites Schroeder-Fasti’s Evolution UD folding machines as uniquely qualified for truly leaning out a process.

“With big parts, a couple operators could take as long as 10 sec. to flip, re-gauge, bring the machine back into position and then bend,” says Prokop regarding other bending methods. “The Evolution’s bi-directional aspect, however, speaks to the efficiency during the bending operation and reducing labor down to one operator. Substantial increases in part accuracy are also realized, because each section of the part is formed while gauged from the same datum point, eliminating the buildup of error witnessed in other forming methods.”

This advantage is referred to as “skip the flip” and is available for up to 1/2-in.-thick mild steel, in forming lengths from 100 in. to 198 in.

“With the Evolution’s ability to bend up and down, you only need one operator,” he explains. “More often than not, with large parts on a press brake, a second operator helps support and manipulate the part during the sequence. A mono-directional folder could usually eliminate one operator until the part is needed to be flipped, and in those situations, the cost-saving efficiencies are immediately eliminated.”

 An enormous amount of labor is saved when operators no longer struggle to manipulate and flip large, heavy or flimsy parts. This creates a safer workplace, and especially so, considering parts are often flipped multiple times.

“If you measure the time to physically throw the bend and multiply that by the number of bends made each day, most companies would be horrified at how inefficient their bending process is,” Prokop explains. “The rest of the time is wasted by set up and material handling as the part is rotated, flipped and re-gauged – turning the nut instead of tightening it.”

The lean aspect doesn’t stop there; the Evolution touts speeds of 150 degrees per second when bending and 300 in. a minute when clamping. It achieves those speeds because of its technically advanced control system, the POS3000 Sheet Metal Designer, as well as its servo-drive, ball-screw system.

“We can drive the different axes of the folder with extreme precision and high operating speeds, unlike ever before,” Prokop says. “Because each screw has its independent servo-driven motors, the Evolution forms fast and accurately – made possible by a newly engineered and rigid frame design.”

Additionally, the Evolution can tilt its clamping beam and folding beam to compensate for extreme off-center bending. Micro crowning and machine deflection are taken into consideration automatically to truly eliminate operator involvement. In these situations, the controller automatically applies slight tilting of the clamping and folding beams based on the part’s position within the folder.

“The POS3000 is another pure lean aspect of this machine,” heralds Prokop. “The control system understands where the part is being formed relative to the tooling, clamping and bending beams. You draw your side profiles with your finger, and the control creates the 3-D profile of the part. The control then automatically optimizes the part program for the best manipulation sequence, tooling strategy, machine position, stroke and open dimensions, applying auto-sequence moves.”

He says, “If the clamping beam needs to open 1 in. to clear a flange, it only opens 1 in. On auto-sequence moves, where the machine auto-executes through a series of bends, the clamping beam only opens enough to clear the material thickness. Furthermore, the control automatically multi-tasks the axes movements, with as many axes as possible moving simultaneously to add more efficiency to the sequence.

“The ability for the control to understand the part and how it fits within the machine and tools, offers a unique programming experience,” Prokop says. “Most controllers position axes constrained by parameters to make a bend. They know little to nothing of the environment in which they are forming. When the control can ‘see’ the entire part as it’s fitting around the tools, it begins to operate intuitively, previously requiring an experienced operator.”

In the end, the Evolution removes substantial portions of operator intervention and consequently, the wasteful movements leading up to Shingo’s last turn of the bolt.

Partnering processes

If necessity is the mother of creation, then the need for increased productivity may just be the father of innovation. To answer the call, RAS Systems LLC developed its FLEXIbend folding machine. The metal folding system, which cuts labor costs in half, works particularly well for small and medium batch sizes in shops with pre-existing press brakes.

“The folder is most beneficial for large panels that required two operators on a press brake, but only one operator when using the folder,” says Rick Wester, Vice President of RAS Systems. “It’s also ideal for complex parts that take three or four different setups on a press brake. On the folder you could have multiple setups across the bed and work the part to the different stations on the same machine. The idea is to pick up a blank and put down a completed part.”

A press brake and a folder have necessary roles on the shop floor, but one thing is for sure, set up on the folder is fast – so fast that most jobs don’t require more than 5 minutes, compared to 15 to 30 minutes on a press brake. The process is simplified, because the tooling is pre-determined during the programming and according to the FLEXIbend’s standard tool set, which comes with basic segments, adapter sets and corner tools.

“When the material thickness and type are entered into the program, the machine knows to adjust automatically for the material,” says Wester. “It also adjusts for springback of different materials.”

Additionally, the universal set of tools can fold 0.023-in. material and then adjust to fold 0.119-in. material. Unlike press brakes, which need multiple sets of tooling, a FLEXIbend only needs one.

“Once the program is completed, the operator can look at the program – the top line displays the stretch-out of the part,” Wester explains. “This stretch-out takes into consideration all bend compensations that occur during the folding operation. Next, the operator looks at the tooling setup, which shows him where to start and stop each setup and what tools to use.”

To further simplify the process, RAS’ crowning method continues to reduce operator intervention after the setup is completed. In test mode, operators check the first part of the run with each bend being tested. After that, the operator only has to place the part on the support table.

“Rather than make the complete bend as described in the program, the folding beam moves 10 degrees and then returns to its home position,” Wester remarks. “At this point, the operator will hear the crowning motor start to run, which means that the crowning system determined the resistance in the test flange and will crown the tooling accordingly. The folding beam then continues to fold the flange to the perfect degree of angle called for in the program and with amazing accuracy.”

Old crowning systems required an operator to enter the depth of the flange, the length of the flange, the material thickness, type of material and tensile strength of the material to be folded. Without test bends or additional programming, a user can now create perfectly straight parts.

“The RAS crowning system is right every time with no guesswork,” says Wester. “Overall, the FLEXIbend has been successful in many shops, and the reason hasn’t been because we replaced the customers’ press brake. Many people think that press brakes and folders compete against each other, but the reality is that the two machines work together.”

For long parts, the 73.30 FLEXIbend can handle up to 126-in. material in 11-gauge mild steel. And for longer part needs, the 73.40 folds 12-gauge mild steel up to 159 in. in length. Overall, the productivity that comes from the FLEXIbend is realized through its range of capabilities and its intuitive ability to produce parts.

Outperforming expectations

Increasingly, fabricators are taking on a heightened level of versatility. Often, achieving that level of versatility requires more manpower and equipment than a job shop has to spare. The answer to the modern-day problem of too many one-off jobs, however, is Salvagnini’s series of panel bending equipment, which eases a wide range of fabricating burdens.

Salvagnini’s panel benders include the P2 Performer, which ups the ante in terms of productivity. The Performer is a compact bender flexible enough to adapt to the varying needs of job shops, and the setup is highly versatile according to users’ ever-changing product mix.

“The purpose of the Performer is to try and unlock bottlenecks,” says Bill Bossard, president of Salvagnini America. “A big part of that is setup. We find that most of our customers are able to justify a panel bender based on the elimination of setup time.”

Bossard backs that strong statement by explaining the time it potentially takes to change over from part to part on a press brake.

“It could be as quick as 5 min., but as long as 20 min.,” he explains. “With the Performer, in the time it takes to load a particular part or punched blank, the machine is resetting itself so the operator can start forming the next part.”

Bossard continues, highlighting that an eight-bend part has been clocked at less than 32 sec., and that operators are only asked to intervene when loading and unloading blanks. Blanks can range up to 98.2 in. long at a maximum width of 60 in. and with bend heights up to 6.5 in.

Furthermore, Salvagnini delivers its patented universal bending tool, making setup quicker and easier. Tool change over is no longer part of the equation. The panel bender can change its setup to produce the next part number within 8 sec., proving that the Performer is able to step in when job shops need to produce small batches at a high rate.

“Once you begin to multiply [its speed] times the number of bends and large number of parts per day, pretty soon you have a significant grasp of how parts can be made faster,” Bossard remarks.

Additionally, it comes equipped with advanced bending technology or ABT – Salvagnini’s proprietary package of control enhancements that guides the bender and its handling systems through the process of automatically forming parts.

To further grasp how easily the benders work, it helps to understand that the blank is moved on a horizontal plane by the manipulator, followed by a rotator fitted on the manipulator that quickly and accurately places the side to be bent in front of the press. Here, the blank is tight in position, thanks to the blank holder’s firm grip. Finally, the bending begins where the material is manipulated in “any number of bends, up or down, in rapid succession.” Because of the ABT control, moving through the sequence requires little to no operator intervention.

“Often times the setup people in a shop are the most senior and experienced individuals,” says Bossard. “This was true in a Wisconsin job shop that integrated a Performer into the shop floor. The senior employees handled the setup, and then they would hand it over to the operator to push the parts through. In an eight-hour day, this customer could be spending about 70 percent of their time doing setups.”

When the Performer came onto the scene, the long-time employees were put to better use. Across the board, operators running a Salvagnini bender continually produce accurate bends in record time, and it doesn’t require a lifetime of experience to achieve it.

International Technologies
RAS Systems LLC
Salvagnini America