In the metal press industry, the difference between success and failure is nearly microscopic – often just a fraction of a millimeter. That's true at North American Tillage Tools (NATT) too, where harrow discs that exceed a half-millimeter wobble tolerance won't meet customers' stringent quality requirements. The plant revolves around precise manufacturing and safety standards. NATT, located in Hamilton, Ontario, is one of North America's premier disc-tillage manufacturers.
Each year, the business produces about 1.8 million steel discs, which are sold to farm equipment manufacturers and dealers for use in planting, tillage and seeding tools. The rugged, earth-engaging tillage parts are usually mounted on a tool bar or row units and used by farmers to break up the soil surface. The disc blades must have high tensile strength to resist breakage when the equipment meets with a hard rock or other obstacle. The discs can't drag and must be of uniform concavity to prevent wobbling.
In recent years, the factory ramped up to 24/7 operations to fill increased orders – but soon discovered it needed even more production capacity. NATT made the decision to add another metal press to its Hamilton facility. The company worked with its machine supplier and system integrator, Allied Innovations Inc. of Hamilton, Ontario, to procure an additional press. The team selected a press that met all of the plant's quality requirements. However, it lacked the safety requirements the plant needed and wouldn't easily integrate with the facility's existing control system.
According to Tom Dyment, major projects manager at NATT, “We wanted to integrate our new press into our automated process line, including all safety and motion control functions – and we wanted the same control platform that we already had.” Using a common control platform, Dyment felt, was critical to ensuring consistent, reliable operations throughout the plant.
Allied Innovations retrofitted the press control system with an Allen-Bradley® GuardLogix® programmable automation controller (PAC) for safety control, tapping the expertise of Gerrie Electric Automation Group for technical support.Based on the Logix control platform, the Compact GuardLogix PAC integrates with other Logix-based controllers used across the facility. All controllers share a common programming and configuration software – Rockwell Software® RSLogix™ 5000 – easing programming and start-up.
“With the Logix system we could design our production line to meet current safety standards out of the box, without further modifications,” said Dyment.
Tim Raymond, vice president of technology at Allied, brings an integrator's perspective to the system. “I've been integrating safety systems for more than 20 years now, and consider the metal form functions blocks to be a big benefit,” he said. The press includes an Allen-Bradley GuardLogix™ Point I/O™ safety module and an Allen-Bradley PowerFlex® 70 variable frequency drive (VFD). The new controller uses an EtherNet/IP™ network to control the drives and to communicate with remote safety I/O.
The GuardLogix controller makes it easy for NATT to integrate a variety of components into the automation line, including its robots, access safety gates, various presses and heating equipment. “By mating our robots with Rockwell Automation controls, we can improve automation performance and help ensure operatorsafety,” said Dyment.
NATT can perform “zone control,” in which one zone of the machine/line is brought to a safe state while others continue to operate. This is possible because the control and safety systems coexist on the same network, and share data between the safety and standard applications. Allen-Bradley PanelView™ Plus 6 human-machine interface software gives operators access to the press machine's data with screen displays that clearly show machine status, menus and more.
By integrating the safety and standard control systems, operators have visibility into all machine events – including safety events – via the HMI, allowing operators to more quickly return the machine to full production after a shutdown. “Our operators really like the PanelView HMI because it's easy to use and understand,” said Dyment.
“Our system integration was completed on time and on budget for one reason,” said Dyment: “The programming environment used with the GuardLogix controllers is so flexible that it integrated easily with our other components.”
As a result, NATT was able to get the new machine online and in production quickly. As variations in tillage machinery continue to proliferate, using a flexible control platform is more critical than ever.
“Our business is a little like the automotive industry,” said Dyment. “Every customer we sell to has a different design requirement, so we need about 25 different machines to produce different types or sizes of discs or disc parts. We rely on the Rockwell Automation programming environment to help us quickly adapt to changes.”
Dyment is counting on the system's flexibility to accommodate inevitable future changes, too. “We knew that our new processing and safety controls would help us meet current production demands and safety standards,” he said. “By upgrading with Rockwell Automation controls, we're future-proofing our production line.”
The results mentioned above are specific to North American Tillage Tools' use of Rockwell Automation products and services in conjunction with other products. Specific results may vary for other customers.