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Buying Automation Equipment


There's more to consider than price

 

By Patrick Waurzyniak
Senior Editor 

  

When buying new automation gear, manufacturers must carefully consider many criteria. Key factors in making any new purchases can include product reliability, ease of use, or new technology, as well as automation supplier experience and support capabilities. Other aspects to consider include energy efficiencies, safety features, and the overall cost of ownership on new purchases.Reliability is critical in automation like this robot from Fanuc Robotics.

Product reliability should be first on any buyer's list, notes Dick Johnson, senior account manager, distribution, Fanuc Robotics America Inc. (Rochester Hills, MI). "From a buyer's viewpoint, I think it's been muddied because most of the robot suppliers are quoting about the same reliability data," Johnson says. "What we tell our potential customers is what our existing customers tell us, that typically the robot is the most reliable piece of equipment installed on the factory floor.

"In the early days, we had quite a few products with linear axes, and we found that the linear axes were almost always the problem. A modern robot is comprised of four, five, or six revolute joints driven by power units, comprised of an encoder for feedback, a DC brake, a reducer, and a servomotor, typically an AC brushless motor. The reliability is extremely high."

With advances in production and modern CAD systems, robots today offer substantially higher reliability than in years past, he adds. "We're totally vertically integrated—we have an encoder factory and we have a servomotor factory. When it comes to the controller, Fanuc is famous for its reliability. I'm sure other companies quote similar, if not the same, reliabilEnergy-efficient components like Rexroth's closed-loop speed-controlled hydraulic pumps reduce energy consumption with every motion.ity, but our controllers are even designed to withstand brownouts, or power failures. We spend special attention to the wiring—we infant-mortality test all major components, which includes the servoamps. Every robot is run in for 100 hrs to ensure the robot is proven and there are no failures."

Fast, responsive support also ranks at the top of any purchaser's list. Support is key, adds Johnson. "It's fair for a purchaser to ask: 'How many service engineers do you have, where are they located?' You don't want the system to fail, but when it does, oftentimes it's critical and the failure could affect the production line.

"At Fanuc, we have a special process for what we call 'down robot,' so that if a customer calls in with a down robot, our target is to get that system up and running within 24 hrs," notes Johnson. "We actually have a special dedicated team of people who only do down robots, and we dispatch them as needed. A lot of times, a part will have broken and we'll send the part and dispatch an engineer to receive it and install it."

Product fit or breadth is another consideration for buyers. "So many times when you get into a job, you might find you need a little more reach, or maybe more payload," Johnson observes. "You may have special needs that you didn't understand. For example, with grinding companies, you certainly have to be IP 67, meaning you can submerge at least the robot's upper arm and wrist in water, but if the coolant is accelerated by the grinding wheel, you also have to be able to withstand high-pressure water spray. So it's important to know whether the supplier you're dealing with has the right products that will fit your unique application.

"Some companies make clean-room robots, some companies make food-grade robots, so you need to ask the question: 'Do you have a product that meets my specific need?' Another thing to ask yourself is: 'How many automation suppliers do I want?' I'm thinking in terms of robots, but I've seen companies that are happy to support two or even three suppliers, and I've seen others that say 'I want to support one.' If you're going to support several, you can have one that has a niche in one area and another one that's got a niche in another area. If you want to support one, then you better pick a broader-breadth supplier to meet your needs." Such considerations also have ramifications as far as availability of training and spare parts, adds Johnson, and ultimately can mean time and money to the buyer.

Ease of use in automation is critical to buyers, who need to know whether a robotic system can be easily programmed and re-programmed for new products. "This gets at ease of use," says Johnson. "Sometimes with automotive, they want to mass-produce the same product for five years, and it's not as important an issue. But more and more, we're getting into what we call general industry, where typically they have a broader product mix. So the buyer should keep in mind the question: 'How critical is it to respond to new product needs, and do I want my people to re-program it, or do I expect the system integrator to do it?'"

How often a robotic automation supplier invests in new technology also plays into the equation. "Is my supplier investing in new technology? Robotics continues to evolve, and I want someone with the resources and development to continue to enhance in new technology," Johnson observes. "Today the four buzzwords are vision, force control, increased accuracy, and Dual Check Safety, or DCS—they've been key for five years. Every customer may not need every one, but if you ask your suppliers about these items and they have a blank stare, you may want to look at additional suppliers."

An integrator's experience level should be another buying consideration. "Has the integrator done it before," Johnson states, "and has he either done a similar system or a system of similar complexity? For example, if he's used to doing single-robot systems and you have a sixrobot system, can he manage that level of complexity? Part of what we try to do at Fanuc Robotics is backstop our integrators. Our growth has been through integrators. Integrators continue to grow in percentage of our overall system content. We have a program called Certified Integrators that designates integrators that have gone through a certain amount of training, and continue to come to our annual training programs."

An experienced integrator should be able to simulate a robotic automation project for prospective customers, he adds. "One example of experience level is whether they provide videos of similar systems, or have they provided a simulation," Johnson says. "That also plays to experience. Should you request a demo to address a perceived risk area? Let's say there's multiple suppliers quoting. It seems like a pretty even heat, and then you ask for a demo. I don't know how many times the demo has made it clear as day which supplier can best meet the need."

Expandability or adaptability often is critical for automation suppliers to be able to deliver customers' change requests as factory-floor realities shift. "Will the system account for future changes? Oftentimes, we quote what we call a top-loader, a robot that rides on an overhead rail, and they'll want a longer rail, and they'll want us to come in and extend the rail," Johnson comments. "A lot of times they may say: 'We need to increase production; can I double the capacity of my system? And by the way, I don't have twice the floor space.' In the case of the top loader, we can add a second robot to the rail. So the buyer should try to think ahead and consider potential future needs, and that's best done before you buy the system."

Technical training needs are another important element. "How will my training needs be met? I've seen similar systems go into two customers, and one didn't work as well because they didn't do training, and the other one worked fine, because they did do training," adds Johnson. "It's always a good question to ask. We probably have some advantages in that we offer online training. We offer regional training, of course, training at our headquarters, and some of our products have tutorials on the product itself, such as our RoboGuide Simulation.

"Our online training is done through our own website. We bought Adobe Connect for about $40,000-$65,000, with Flash programming; we bought the toolkit and this animates PowerPoint, allows voiceover, and makes a very friendly package. The user can work with a self-paced tutorial, and there are tests at the end of it, because if the end user buys it, he wants to know not only did the employee take the online training, but did he pass?"

Energy efficiencies and safety capabilities are two more considerations buyers also should look at when mulling over new capital equipment purchases, notes Karl Rapp, industry sector manager, automation and machine tool, Bosch Rexroth Corp., Electric Drives and Controls (Hoffman Estates, IL). Total cost of ownership factors including automation equipment energy consumption and safety capabilities are key in Europe and Japan, notes Rapp. Standards have mandated more stringent requirements there, but those factors have yet to make much impact in the North American market.

Rapp says key criteria for manufacturers to consider when evaluating automation equipment include determining initial purchase cost, which is typically lowest-cost bidder in North America; determining infrastructure costs including space, physical installation, electrical supply system, water, air, and disposal of excess waste and heat; calculating annual operation cost including energy consumption, lubrication consumption, tool consumption, and maintenance; and comparing the total cost of ownership over the years of expected machine life.

"Here in the US, in the past years, it always seems like the purchasing guy wants to buy the cheapest capital equipment possible," observes Rapp, who notes that energy-efficient systems can pay off over the long run. "That is one of the mindsets that has to change, and we all know that."

Bar straightness is a key consideration when purchasing gear like this Edge Technologies Ecofeed bar feeder.Buyers also should determine if machines comply with the latest machinery and component safety standards, such as ISO13849-1, IEC61508, and others, Rapp insists, as these are global standards that with very high probability will get adopted by ANSI, eventually influencing OSHA and other regulatory bodies in the US. "Safety should be integrated transparent to the operator, meaning the operator must not make safety decisions, the control system grants access when it is safe for the operator," Rapp explains. "Integrated safety should result in higher automation availability."

For simpler automation systems, like bar-feed equipment handling bar stock, the main keys to purchasing decisions are the customer's product volume and materials, what type of machine tool the bar feeder is attached to, and the price range desired by the customer, notes Rick Bauer of Edge Technologies (St. Louis). "First, what is the product volume and material that they're going to be doing? In other words, are there 50 of this part and 100 of that, or are we looking at a 10,000-piece dedicated run? The second thing would be what type of machine tool is it going to be attached to? Thirdly, what price range do we want to fall in? That starts the whole process because we have a tiered product," Bauer notes. "We have the Edge product, which is a great economical product, and then we have the FMB, which is touted as the biggest [heaviest] bar feeder in the industry."

A first-time buyer probably will lean toward the Edge line due to cost considerations, Bauer says. The Edge line includes the new Rebel Ecofeed short-bar loader for CNC lathes. The Ecofeed is a compact, economically priced short-bar loader that features 5-65-mm diam capacity range for feeding spindle-length round, square, hexagonal, and shaped bar stock into CNC lathes. It offers the advantages of auto bar loading with a small footprint and an affordable price tag with a large magazine capacity, allowing for long untended operation. "If a customer says 'I want to do 2" [51-mm] brass hex, the guy needs the 6000 lb [2700-kg] FMB," Bauer says. "Those are a few criteria up-front that really help us to do the qualification. The job run and material, the machine tool, and then, of course, the ability to pay. That's where it all starts."

Edge's FMB line, which is built in Germany, can support heavy stock due to its cast-iron base, giving it the rigidity required to do the job, Bauer says. "It typically uses a castiron base, because of the supporting structure of the machine," he says. "The 5200-8000 lb [2340-3600-kg] bar feeders have the best ability to handle harmonics and vibration, and won't pass that on to the tool tip. Vibration at the tool tip is going to do several things—either produce a bad finish, or it's going to decrease the rpm capability and affect the speeds and feeds—so vibration damping is necessary for cycle time and good-quality finishes.

"Where we really like to counsel a customer is when it comes down to bar straightness," Bauer adds. "In other words, if a guy says, 'I need to run 10,000 pieces of aluminum parts' what goes off in my mind is, 'this is a great job for a 12 footer—it's going be a high-volume, dedicated job that will require little to no changeover, so our best efficiency's going to come from a 12' [305-mm] unit. The industry has agreed that a general rule of thumb for bar straightness is 0.007" [0.18-mm] per foot, or 0.020" [0.51 mm] over 3' [0.9 m]. That's something the customer needs to remember, if he knows he's going run these 12' [3.7-m] bars, they better be straight to achieve the maximum rpm."

Another factor affecting straightness is how the bar stock is cut, Bauer says. "It's our job to inform them of the straightness. There are clearly performance differences between shear-cut and saw-cut material," he adds. "Saw cut doesn't apply any pressure to the end on the bar, so it's very straight all the way through. Shear-cut material has a deformation on the end of the material that's created when the shear impacts the bar, and so it creates a bend for 4-6" [101.6-152.4 mm] on the end of the material. As we try to hold that on center, you can understand what's going to happen. The bend will create a lot of vibration, because instead of being on-center, the bar is going to run out.

"We do the whole gamut, but about 90% of the bar feeders go on fixed-headstock and Swiss lathes, then we get all kinds of obscure requests from there—centerless grinders, cold headers, cutoff saws, and even some VMCs with indexing tables get bar-fed. It's probably one of the the most-overlooked parts of the business."

 

This article was first published in the December 2009 edition of Manufacturing Engineering magazine. 


Published Date : 12/1/2009

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