Modular IO Cuts Wiring Time 20%

RRR Development reduces machine wiring time by 20%, helps tire manufacturers decrease maintenance woes. Time to market increases, boosts sales by $2.5 million a year.

By Sandy Holden October 27, 2011

As a major contributor to the more than 1 billion tires manufactured annually, RRR Development has a talent for staying in the productivity “fast lane.” Headquartered in North Canton, Ohio, with additional engineering and manufacturing in Ho Chi Minh City, Vietnam, RRR Development is the only U.S. manufacturer of passenger, light truck, motorcycle and industrial tire assembly machines. It designs and builds single, multistage, and specialty tire machines for 34 tire plants across the globe. To extend the lifecycle of its equipment, it offers U.S. customers fabricating, grinding, panel, and assembly shops.

RRR Development consistently invests in new technologies to help customers. The company recently applied a new modular wiring technique to its tire machines, helping to reduce build time by nearly five days while easing installation, operational, and maintenance activities.

Challenge: Size, speed

Engineering staff from RRR Development researched various wiring methods to help assemble, disassemble, and install their machinery faster.

“After conducting our research, we designed a system with a distributed I/O architecture,” said Robert D. Irwin, vice president, RRR Development. “The money we saved in the reduction of the main control panel size quickly dissipated when we added several remote junction boxes housing the distributed I/O modules. The boxes simply took up too much real estate around our machine. As a result, the savings we anticipated with the system did not materialize.”

The engineers liked the distributed I/O architecture but turned to another supplier, Irwin said, “To apply a modular wiring technique that did not require a PLC network, additional hardware, or training.”

The new wiring technique was used in the new RRR First-Stage Tire Building Machine (TBM), developed to be used where all tire-manufacturing materials come together to be wrapped into a barrel shape. After the first stage is complete, the machine then applies steel belts and treads to a second-stage product, helping form the tire shape. The machine’s prime strength is its ability to produce multiple tire styles, including agricultural, passenger, light-truck, and motorcycle tires, which previously would require three machines.

To handle synchronization of the machine’s movements, the RRR First-Stage TBM is equipped with a programmable automation controller (PAC), servo drive, and low inertia servo motors. The controller handles the machine’s sequential and motion control movements, eliminating the need for a separate motion controller and associated wiring for each function. The integrated servo drive helps enable fast acceleration and deceleration of the machine, and produces torque up to 250% of continuous rated current. This high-peak current helps downsize the drive power supply and axis modules, and reduce the required panel space. The control solution integrates seamlessly with third-party pneumatic valves on EtherNet/IP Ethernet protocol from ODVA.

Key to the machine’s successful design was streamlining the wiring. “We really wanted to reduce the amount of time and labor that went into a simple junction box,” said Irwin. Engineers typically design machines and control cabinets as separate units, a design that requires massive amounts of wiring and time to interconnect the two. “The wiring for a complex machine like this involves 17 unique steps,” said Irwin.

To augment the wiring savings it achieved by using one control platform, RRR Development selected compact, distributed I/O components that could be placed directly on the machine. This included an I/O module, distribution blocks, and system cables that connect I/O wiring to the controller. By using convenient, prebuilt cables and connectors, panel assemblers connect field devices to the programmable controller without DIN rails or terminal blocks, while maintaining environmental integrity of the panel enclosure.

Results: 1 week less

“We need the flexibility to build our machine in stages, as well as the ability to quickly assemble and disassemble it for shipping,” said Irwin. On average, it takes 16 to 20 weeks to manufacture and factory test a machine prior to shipment. With an on-machine wiring technique, RRR Development reduced its wiring process from 17 to 6 simple steps, helping reduce build-time by nearly an entire week. “By reducing build-time for our machine by nearly 5 days, we can produce 10n more machines per year, which is equivalent to a $2.5 million increase in sales annually,” said Irwin.

RRR Development now easily designs 30 to 40 complete systems and 80 to 100 major system upgrade assemblies per year. In parallel with the production of these products, the machine builder also can make thousands of custom parts, subassemblies, and total systems for its customers.

The wiring system helps RRR Development increase its capacity, but helps its customers reduce risk. The plug-and-play wiring systems minimize wiring errors because there are fewer points of failure. “If we do find a maintenance problem, it is now much easier to fix,” explained Irwin. A complete wire swap used to take up to an hour to complete. Now, addressing a problem takes less than a minute, significantly reducing the potential impact on the customer’s production schedule.

“We can get machines up and running in a fraction of the time,” said Irwin. “At our last installation, we had the machine reconnected and up in 2 hours, a task that could previously consume up to one and a half days.”

The new system also uses less floor space. Control cabinets can occupy a substantial amount of space on the plant floor. “By reducing the amount of wiring and using compact, preconfigured modules, instead of bulky terminal blocks, our customers have much smaller machine panels,” said Irwin. “We’re seeing more than 25% space savings with our new distributed I/O architecture.”

On-machine controls also provide end users with improved troubleshooting and control system reliability. “If a cable or sensor needs to be replaced, it is an extremely simple process,” said Irwin. The controller collects diagnostics from the field devices and alerts the operator to faults via the machine’s human-machine interface terminal.

“In the past, end users needed to sort through a complex panel of terminal blocks and wiring connections. Now, operators can look at the LED lights on the distribution block for each I/O circuit open mounted on the machine assembly instead of opening a junction box and needing a meter to troubleshoot a problem. This open visibility helps to quickly bring our machines back on line, helping our customers to maintain even higher production and profit levels.”

With its new control system architecture, RRR is now more quickly building its high-performance machines to help the company and its customers maintain a position in the fast lane.

Technologies that create less wiring

“RRR Development initiated the help of Rockwell Automation, the industry’s largest supplier dedicated to automation,” said Robert D. Irwin, vice president, RRR Development.

RRR First-Stage TBM has an Allen-Bradley ControlLogix programmable automation controller, Kinetix 6000 servo drive, and MP-Series Low Inertia (MPL) servo motors from Rockwell Automation. The ControlLogix controller does sequential and motion control movements in the machine, eliminating the need for a separate motion controller and associated wiring for each.

Distributed I/O components from Rockwell Automation on the machine included Allen-Bradley 1667 PanelConnect module, 898 distribution blocks, and system cables.

RRR Development used Rockwell Automation’s On-Machine wiring technique.

Sandy Holden is market development manager, OEM business, Rockwell Automation.

Technologies that create less wiring