Powering up with a punch
Tooling upgrade cuts costs, reduces maintenance for generator manufacturer
When Generac Power Systems, a generator manufacturer, went looking for ways to increase the useful life of its punching tooling, it tried several strategies before it settled on the Optima® coating provided by Wilson Tool International® Inc. When Wilson later introduced UltimaT, a tool steel, Generac tried it also. Generac eventually converted all of its punch tooling to the new tool steel and coating.
For 45 years Generac Power Systems has helped homeowners and businesses withstand the unpredictable forces of Mother Nature with standby power-generation equipment. So when the company's Eagle, Wis., metal fabrication facility needed to power up the productivity of its punch press tooling, it looked for technological advancements to help its operation run more smoothly.
Located near Milwaukee, the 240,000-square-foot plant fabricates and installs durable generator enclosures made of sheet metal up to 1/4 inch thick. Nearly 1,000 employees at four Generac manufacturing facilities in Wisconsin and Iowa rely on the Eagle plant to put the final, crucial layer of protection on gas and diesel generators with output from 3 to 600 kilowatts.
A generator is not just a modern convenience that minimizes disruptions to daily life. An on-site power source can be a matter of survival. For airports, hospitals, military bases, and emergency workers, Generac generators provide an indispensable standby power supply. For example, Generac's products played a vital role in Hurricane Katrina relief efforts.
The company uses advanced design, engineering, and manufacturing methods to ensure its products withstand the potential wrath of severe weather. Each product is also subject to strict quality control measures and exhaustive testing.
|For health care facilities such as hospitals, having an on-site power supply can make the difference between life and death. A hospital equipped with its own generator can continue to provide critical care when utility power is fluctuating or interrupted.|
Getting Proactive on Punching
Fabricating the heavy-duty sheet metal required for the generator enclosures places a heavy burden on punch press tooling. Tooling wear and tear—plus sharpening and replacement costs—have always been a constant battle. Jack Handeland, tooling engineer at the Eagle facility, is no stranger to tooling issues. "They call me the "tool god,'" he said in jest. But he stops laughing when he considers everything he's been through to get more life out of his tooling.
Generac runs three Amada CNC punch press models—the Vipros 358 and models from the Pega and Coma series—to keep up with demand for generator enclosures. In the past the presses were capable of doing the job, but tooling was causing a bottleneck. Punch tips wore quickly because of the sheet metal's thickness. Tools often had to be changed to remove material buildup (galling) and for sharpening, decreasing that press's green-light time.
Punching quality also was an issue. In the later stages of a press run, dull tools produced burrs on the holes, requiring secondary deburring. This process added labor and cost, consuming resources that could be put to better use elsewhere.
Handeland had made several attempts to remedy these tooling problems. They produced mixed results or were only temporary fixes.
"I've always been very proactive to get more out of our tooling. I've tried different shears on the punch and draw polishes. I've explored different tooling companies and styles as well. Nothing provided the productivity we were after."
|Generac found that punches do more than merely make holes. They have a role in productivity too. Changing to longer-lasting punches increased the time between tooling changeovers, which increased the punch presses' uptime. It also reduced the labor needed to remove galled material from the punches and reduced burrs and subsequent deburring.|
Quest Leads to Coating Solution
After an exhaustive search, Handeland learned that certain TiCN (titanium carbonitride) coatings had the potential to benefit tooling productivity. He began by using a small batch of Wilson Tool punches with Optima®, a TiCN coating specifically engineered for punching applications.
"Suddenly we were getting more hits between sharpenings, greatly reduced galling, and longer tool life," said Handeland. "I was very impressed with the results. Once I saw that, we started using Optima-coated punches on all our tooling."
By adding the tool coating, Handeland was able to save substantial time previously devoted to tool sharpening and removal of galling. However, he saw there was still room for improvement on some of his toughest punching assignments. In sheet metal parting, for example, considerable wear was still a problem.
Handeland discovered that the properties of some high-speed steels could provide superior hardness and wear resistance, but to his knowledge, they were not available for punch press tooling. "I had heard about these types of steels for years, but they weren't yet commercially available."
A New Tool Steel Emerges
About a year after he began using the Optima coating, Handeland finally found the tool steel he wanted—Wilson Tool's recently introduced Ultima™ premium tool steel, which was engineered to address durability problems similar to the ones he faced.
"I started using it on a small batch of tools right away, just like I did with the Optima coating," Handeland said. The new tool steel did not disappoint Handeland, and he rolled it out to his entire tooling inventory.
"Our tools last remarkably longer, and the quality of our holes is much better now," said Handeland. "Now the edges are cleaner with fewer burrs, so there's less labor time and cost devoted to secondary operations for smoothing and cleaning the holes. It saves a lot of time."
Now it's not only time that Generac is saving. Last year the company's tooling costs were down 30 percent, and it is getting five to six times more hits from its punching tools.
Generac Power Systems, Hwy. 59 and Hillside Road, P.O. Box 8, Waukesha, WI 53187, www.generac.com
Wilson Tool International® Inc., 12912 Farnham Ave., White Bear Lake, MN 55110, 800-328-9646, www.wilson tool.com
The FABRICATOR is North America's leading magazine for the metal forming and fabricating industry. The magazine delivers the news, technical articles, and case histories that enable fabricators to do their jobs more efficiently. The FABRICATOR has served the industry since 1971.