Precision-bent parts reduce scrap and keep downstream processes moving
By Russ Olexa from FFJournal.net
Today, a long production run could be as many as 20 parts. But for many companies, the norm is often one or two parts. This has changed part production, with companies relying on equipment that gives them a perfect first-piece part every time.
Started in 1990, Precision Cutting Specialties, Eunice, La., primarily offers flame- and plasma-cutting services for the oil field industry. It mainly cuts parts from 3/4-in.-thick to about 6-in.-thick steel. Recently, it’s added laser-cutting and bending services, including press brakes.
Through the years, the company’s business model changed as precision cutting served the all-terrain vehicle and truck accessory industries for aftermarket parts. But some of its growth came from the health and fitness industry, which needed volume plate burning.
“We’ve purchased equipment to serve some of these industries that have come to us for help,” says Stan Loewer, company owner. “Some of it started out with a person who might have a small shop making 50 parts a month. We’ve seen some of them grow from 50 parts a month to 20,000 a month over the past 10 years.
“Our volume production allowed us to do daily cutting, and in the meantime, we got out and sold our services to broaden our customer base,” he continues. “We’re a contract manufacturer, but we’re not making any finished products. We’re doing sub assemblies, cutting, bending, light welding, but for the most part, everything we’re doing is first- and second-stage processing to move it on down the line to the customer, who’s doing the final fabrication.”
Into the bend
In 2000, PCS bought its first small CNC 65-ton press brake with a 6-ft. bed.
“We were doing quite a bit of plasma and laser work, and we just needed a press brake to bend parts,” says Loewer. “So we bought this little machine and ran it until last fall, when we needed something bigger.”
In late 2008, PCS purchased a 150-ton Accell press brake with a 10-ft. bed from Accurpress America Inc., Rapid City, S.D.
“We also purchased the machine with a six-axis back gauge and offline programming software,” says Loewer. “It has spring back and material thickness sensing, too. It has every option we could put on it. We bought the back gauge because we’re getting into quite a few nonparallel flanges on parts–bizarre angles on odd-shaped parts. Along with the offline software to gauge these parts and bend them correctly, the back gauge has given us a lot of flexibility. It’s been a phenomenal investment for us.”
Loewer says the company did its due diligence in looking for a new press brake but trusted its local machine distributor for a recommendation.
“We looked at quite a few different manufacturers,” says Loewer. “I felt reasonably certain that Accurpress was the way to go because it’s built in North America, and parts and service are readily available and in the area.”
Loewer also says the new Accell reduces scrap while increasing production.
“In the past, when we were cutting blanks or prototyping parts, the laser operators were cutting two, three or four extra parts for our press brake setup to make sure their bend angles were correct because material thicknesses changed from one plate heat to another.
“With the Accurpress, we’re now able to take a part from a SolidWorks software 3-D file straight to the offline programming software,” he continues. “Then we import the 3-D object, laser cut the part, go directly to the press brake with the program that was made off the same 3-D file and bend the part. Many times, we’re getting the first article passing inspection. I’m not going to say we don’t cut some extra parts, but it has just been phenomenal that we could get a good first part that we could sell. At times, we [used to have to] cut up to eight parts to get one right.”
On the Accell press brake, precision cutting can primary bend steel from 10 gauge to 1/4 in. thick. It runs carbon steel 70 percent of the time and stainless about 30 percent.
Enter Vermeer Corp.
Starting out as a one-person company founded by Gary Vermeer in 1948, Vermeer Corp., Pella, Iowa, today has more than 2,000 employees and more than 1 million sq. ft. of production space in North America and around the world. Vermeer is a manufacturer of agricultural, environmental and industrial equipment.
To build its equipment, the company employs sheet metal manufacturing processes and machining, using CNC lathes and machining centers.
At its environmental product segment, Vermeer is using lean manufacturing techniques, says Scott See, area machine shop manager, and the company is developing kit-style parts processing in its machine shop. However, the bending processes have been the typical bottleneck.
“For the kit-style packages to work, we needed a press brake that was extremely fast and able to change over quickly to process different types of jobs,” says See. “So we went with two Accurpress Accell press brakes. One is a 90-ton model, and the other is a 190-ton.
“Several employees reviewed our prints and decided that 70 percent of the parts could be bent using a lower-tonnage press brake. The other 30 percent of the parts could be run across our larger 300-ton press brake that’s slower because it has more stroke to contend with. So we bought a lower- tonnage press brake, which allowed us to buy tooling that was precision ground. The Accell press brake could also store the programs at the machine. With the fast and simple setup allowed by the precision tooling and touch-screen programming, we could bend the part within one-degree accuracy.
“On our older-style benders, we achieved less accurate results,” he continues. “We have six-axis automatic back gauges on the Accell press brakes to do all types of different bending angles. We also have a spring back indicator on the machine, but we aren’t currently using it.”
Finding the right brake
To find the right press brake, John Castings, manufacturing engineer, says Vermeer went to various trade shows.
“In the past, we had rocker-style press brakes as opposed to hydraulically driven ones,” he says. “We were also trying to pursue machines that could be programmed right at the control.”
One of the new Accell press brakes has allowed the company to eliminate two press brakes, the one it replaced and another, because of its high productivity.
In fact, the press brake operator has increased the output from the old press brake to the new one by a minimum of 50 percent, says See.
“Not only that, but the quality has also increased substantially,” he says. “It’s smaller and quicker to load, so our setups are much faster. With the other brake, we were using a 12-ft. die to bend a 2-in. part. When we went to the new Accell, we bought segmented tooling. Now we can put in a 2-in. die rather than a full-length one. It has snap-in-style tooling using a power clamp.”
As with many companies, Vermeer’s part volumes might only be one or two pieces. Thus, first-bend accuracy is imperative.
“Some of our parts are for equipment that we only make one part at a time,” says See. “We finish it, and then we start on another model of equipment. Due to the large equipment produced at this plant, we do primarily three to four pieces per week. Some of the steel parts have six to eight bends in them and can be anywhere from 14 gauge to 3/8 in. thick.
“If we needed another press brake, we’d go with Accurpress,” he adds.
Original Article from the FFJournal