News

Oct 19, 2023

Bringing metal cutting and folding in

Ralph Wehnes, president of SW Roofing, slides a piece of prepainted sheet metal

Ralph Wehnes, president of SW Roofing, slides a piece of prepainted sheet metal into his company's Mac-Shear MRGM 3060.

The addition of modern metal fabricating equipment is not just a recipe for success for large manufacturing companies. The right mix of new technology can elevate the capabilities and the reputation of small companies in the same way that strategic capital equipment investments can do for larger organizations.

Ralph Wehnes, president of SW Roofing in DeKalb, Ill., got his start selling commercial roofing 20 years ago. About 10 years ago, he started making metal pieces for some of the roofing jobs they were doing. That business grew and eventually became his "real job," he said.

After growing his company into a successful small business in recent years, he knew that he wanted more. He had a friend who owned a similar but larger metal roofing operation with an extensive metalworking shop. He’d visit and wonder why he couldn't have a more sophisticated operation like him. Additionally, he’d get frustrated when he had to outsource metal parts to nearby companies that didn't deliver as promised. "You really are a hostage if you can't make your own stuff," he said.

In summer 2021 he took the leap and invested in a new CNC shear and a CNC folding machine. The small company has now positioned itself for big things in the near future.

Before this summer, SW Roofing relied on a slitter and a pan-and-box press brake for its metalworking needs. They were used primarily to make flashing and special pieces, like roof edging, for the commercial metal roofs that were installed. The metal parts are all prepainted, with the steel ranging in size from 22 to 26 ga. thick. SW Roofing also processes some 0.019-in. aluminum.

"The problem with making it by hand like this is that it's not always straight," Wehnes said. "You can make 10 pieces, and nine out of 10 might fit, but one doesn't. That's a problem."

Slitting, for example, involved running a long section of metal under a row of small wheels that did the cutting. Wehnes said a regular job called for processing about 20 metal blanks through the slitter to create 60 pieces. So, each large metal piece had to be run through the slitter at least two times to get the resulting three pieces. It was a two-man job because of the awkward size of the metal and the need to grab it after it was processed and feed it back through the slitter again. Sometimes it involved three people, given the size of the sheet metal blanks. Wehnes said that processing those metal sheets to create the resulting 60 pieces could take about an hour.

"With the slitter, you would try to teach somebody how to keep the metal straight while it's getting cut, but you would end up getting a little twist in the material. And once you twist the cut, the pieces are crooked. And you really can't measure that," Wehnes said.

The slitter also ate up a lot of shop floor space. Wehner said that in addition to the machine, two tables were needed to help process the sheets.

The pan-and-box press brake worked fine, if the pieces were straight, which was not always the case. But the manual nature of the bending process was tedious and slow. For a person who describes his hobby as "buying tools," Wehnes had had his fill with the older metal fabricating equipment. That's when he placed his order for a Mac-Shear MRGM 3060 and an Erbend MFB 3220 from Mac-Tech, a machine tool distributor with headquarters in Milwaukee.

Wehnes programs his jobs at the folding machine.

Wehnes considered getting just one new piece of equipment, but when he thought the entire process through, he realized that the combination would produce the best results. The shear ensures straight pieces, but it wouldn't ensure a straight bend on the manual press brake. The CNC folder could produce straight parts only if the slitter and its operator were generating straight cuts. In the end, Wehnes said that the CNC equipment combination would overcome the many shortcomings of the manual equipment.

Six months later, SW Roofing's metalworking efforts no longer involve waiting. It's cut, fold, and get on to the next task.

The shear offers the precision cut that the slitter couldn't deliver, according to Wehnes. An operator slides the metal blank onto the sheet table and underneath the blade and positions it squarely against the CNC backgauge. When the operator is confident everything is squared up, he hits the pedal, and the shear delivers a straight part, coming within a thousandth of the programmed dimensions.

Wehnes added that it's quick and easy to adjust the length of the cut. The operator plugs in new measurements, and the backgauge adjusts automatically. Because SW Roofing is cutting metal within a pretty narrow window, operators really don't have to adjust the shear for changes in material thickness.

What kind of efficiency is SW Roofing getting from its new shear? Wehnes said that the same operation of cutting 20 larger pieces of sheet metal into 60 smaller pieces takes only 15 minutes with the new shear.

He's finding the same sort of efficiency with the folder. The operator programs the machine, places the blank against the automatic backgauge, engages the pedal, and watches the tooling come down to grip the blank and the folding beam swing out to bend it. Typical jobs call for about six to seven bends, Wehnes said, and an operator can run through those once they are used to working with the folder. One of the main challenges is maintaining control of the long sections of sheet metal as they often need to be flipped during the job. (The bending area is 10 ft. 6 in. long.)

"After about five hours on that machine, I literally felt like a professional," he said. "I felt like I could go into a sheet metal shop and they would think I had been doing this for 20 years."

Wehnes found that he would rather program the machine using what the control software calls a "line-by-line" approach. Using the control interface at the machine, the operator inputs the length of the material and the angle or the tooling action required for each step of the bend sequence and then begins the job.

"For example, if you are going to form a piece with two hems and that required three bends, you can program that in 20 seconds. Then you basically just grab your metal and you start bending," he said.

Offline programming was more than SW Roofing needed. Wehnes liked the flexibility offered by the line-by-line method because he could tweak it on the fly. Sitting down to create programs that would need to be re-created if something had to be changed was a waste of time. Also, the sheet metal pieces formed on the folder are often unique to each job, so creating offline programs that are saved for future didn't make a lot of sense.

Wehnes retrieves a completed part from the Erbend MFB 3220 folding machine.

"I can teach somebody how to bend metal on this folder in five minutes. He can then be up and running," Wehnes said.

He added that SW Roofing is saving tons of time that used to be tied up with laborious efforts to cut and form the sheet metal. Pieces can be made in minutes, not hours. That means jobs can be completed faster, and more jobs can be added to the schedule.

Having total control over the schedule is probably the ultimate benefit of the investment in these modern manufacturing machines, according to Wehnes. If a part doesn't fit out in the field, another one can be fabricated quickly. Jobs can be scheduled confidently because metalworking is done in-house, and the company is not at the mercy of sheet metal contractors who might or might not meet a delivery date for cut and formed parts. The company is not dependent on any other entity when it comes to meeting its own customers’ needs.

"I feel like I’m more prepared than I’ve ever been for the future. I have more control than I probably ever had with my business," Wehnes said.

"I think this will allow me to open more doors down the road—maybe even have another income stream for just making metal parts for other roofers."

SW Roofing has taken the next step in its business growth. Soon it’ll find other companies wanting to stop by and check out what it's doing as part of that growth.