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Flexibility is Hallmark of Automated Assembly System

A manufacturing engineer uses customized tooling to adapt the assembly system to a customer's unique needs.

Manufacturers who yearn for customized assembly lines that ideally increase production while reducing mean time between failures, should be careful what they wish for. A tailor-fit system may suit immediate needs. But when it goes out of style, it can quickly morph into a useless, wasteful luxury. Ask Bill Bargholtz.

Mr. Bargholtz, senior manufacturing engineer for Ark-Les Custom Products, an Illinois Tool Works (ITW) company located in New Berlin, Wisconsin, has come to believe that customized automation may very well be a synonym for obsolete. The issue, he believes, is adaptability.

"If each portion of the machine is customized, you may not have any common parts for repairs. Or it can't be converted to run a different product," he said. "We've purchased customized machines, but when the product run ended, we cut them up and threw them away. They couldn't be adapted to other uses."

Compare that outcome to a standard platform that Ark-Les Custom Products purchased from Mikron Assembly Technology (Milwaukee, Wisconsin) four years ago. "I can take tooling stations out of it and do something completely different," Bargholtz said of the Mikron setup. "But the same frame is there, the same motor. If this product dies in two or three years, I can retool this platform for about one-third of what I paid for it."

The product that Bargholtz was referring to is a six-part, hidden washer lid switch that Ark-Les Custom Products makes for Whirlpool. Four years ago, the appliance OEM requested an upgrade of the complex switch, which is assembled in Wisconsin and then shipped to Whirlpool for installation. Bargholtz said that the switch assembly is challenging because the entire component is not much bigger than a pack of cigarettes, and it includes a set of small, tricky spring contacts.

When developing a product for its various clients, Ark-Les Custom Products' engineers create a solution, and then build prototypes to test the design. Once the client has given the green light, Bargholtz's department steps in. First they determine the production volume that the client will need. From there, they determine if automation is required. In the not-so-distant past, projects that required less than five million units annually were deemed unsuitable for automation. Those projects would often be shipped overseas and hand-assembled. But times have changed. Now automation is recommended even when only two million units are needed annually.

Since Whirlpool would require at least five million units, Bargholtz knew that automation was justified. He also knew that to meet production demands, he would need a system that was fast, durable, and could maintain a high level of quality control.

"In today's market--the complexity of things, and quality demands--you need to have equipment that verifies just about everything that you do," he said.

The next step for Bargholtz was writing a detailed six-page specification report that would be sent to companies that wished to bid on the project. He knew from experience that a report that did not adequately explain his production needs could end up costing Ark-Les Custom Products a lot of money. "You need to specify everything, so when you get this machinery, it does exactly what you want," he said. "I've seen enough misunderstanding to know that it ends up costing you double before you clean up the mess."

The eight bids he received ran the gamut of customized automated solutions. Some proposals were delivered electronically in CAD files; one bid was presented in the form of a pencil sketch. "It went from things I pretty much knew wouldn't work, to the Mercedes Benz of machines," said Bargholtz.

The bid by Mikron impressed Bargholtz. Basically, the assembly system would comprise three modules tied together with conveyors. Since the frame, camshaft, and motors were standard issue (Why reinvent the wheel?), Mikron could reduce the lead time for delivering the system and deal with the specificity of the tooling. And Bargholtz appreciated the questions that Mikron asked and the answers that they provided. It also didn't hurt that Mikron was an international firm: Since being purchased by ITW, a Fortune 500 company, the horizons had expanded for Ark-Les Custom Products.

"I can find the Mikron standard frames all over the world," said Bargholtz. "It's the tooling that's unique."

There was one problem, however. The Mikron bid was the second highest of the bunch. To convince management that the expenditure would actually save money, Bargholtz devised a matrix that showed how each of the eight automation proposals would perform, financially and from a production standpoint. The comparison made it clear that some of the proposed customized automated systems simply would not hold up under the pressure of producing five million units annually. But the Mikron system had the speed that Bargholtz wanted.

"Mikron came in with booklets, clear illustrations of sequence of events, and data on how many units you could get off in an eight-hour shift," Bargholtz enthused. "They had all the right information and calculations. When you present that to management, you can make the argument that if we spend the money now, it will be worth it. They're used to hearing me say, 'You can pay me now or you can pay me later.'"

In fact, Ark-Les Custom Products paid for the Mikron system in less than half the time that was projected. A key factor was reduction of labor costs. The Mikron setup requires one employee. The production line for an equivalent earlier incarnation of the washer switch needed 12 assembly people and two maintenance workers.

"If you put less labor into it, you give the customer a better price and still make a nice profit," said Bargholtz. "And we gave them a better switch besides. All around it's a better deal."

Although some adjustments were necessary following installation at the Ark-Les Custom Products plant, they were minor and could be done in-house. And when members of the parent company, ITW, visited and observed the system in action, they were very impressed. "The Mikron is assembling very complicated parts," noted Bargholtz. "To look at it, it seems simple. But to do all that is amazing."

For more information on Mikron Assembly Technology, contact Paul Beduze at (262) 742-5316; Fax: (262) 742-5319.

For more on Ark-Les Custom Products, visit www.Ark-Les.com.

Custom Electromechanical Devices for the Appliance Industry

Ark-Les, an Illinois Tool Works Company, is a major supplier of engineered user interface solutions to markets that include appliances, telecommunications, motor controls, and data processing. One of the business units of Ark-Les is Ark-Les Custom Products, which makes custom electromechanical devices for the appliance industry, mostly for Whirlpool and Electrolux. Typically, these appliance companies have needs for components such as switches, door locks, alarms, and relays.

"We create custom products for them," says Bill Bargholtz, senior manufacturing engineer for Ark-Les Custom Products. "If it's large volumes they want, three million or more pieces, we'll automate the process."

An example is the Hidden Washer Lid Switch, a tamper-resistant switch that prevents a washing machine from running if the door is opened. The parts that make up the component are a body, a cover, terminals, wire, and a switch. Ark-Les injection molds the covers, stamps the terminals, and uses wire termination devices to put the terminals and connectors on the wire. The company has also built several important design features into the switch, which has a patented self-alignment feature and no fasteners. Its housing is designed so that all of the electrical connections are located above the washer top. Additional features include a standardized one-piece Molex connection system for ease of assembly, burr-relief and contamination fail-safe features, and resistance to switch-point issues associated with oil canning of the lid.

"The hidden washer lid switch is basically a safety switch," says Bargholtz. "If someone opens the door, the machine shuts off. With older washing machines, you could put a screwdriver in the little slot to make it run with the door open. But this one is called the hidden washer lid switch because you can't see it, and so it can't be overridden."

According to Bargholtz, the washer lid switch is not sealed for water resistance, but it doesn't have to be. The way that Ark-Les designed it, if liquid drips onto the washer, it will run off before it runs into the switch. "We've come up with a snap-action switch that works quite well and is very simple," says Bargholtz. "There's a hook that's part of the hinge on the lid. The hook will swing up into the switch and close it--this is the self-alignment feature. We created the snap-in device so they don't have to use screws; it just pops into the slot. Doing these things reduces parts overall, and we can sometimes use parts for one switch in other types of switches."