Un grande salto nel taglio dei tubi di grande dimensione. L’investimento distingue il produttore dello Utah. – FL 400
Diversi anni fa Dee Roskelley ha dovuto affrontare una sfida comune a molte aziende metalmeccaniche che lavorano su commessa: dove effettuare il prossimo investimento? Roskelley è vice presidente per l’ approvvigionamento e la tecnologia di produzione presso la ditta Richards Sheet Metal Works, in Ogden, nello Utah- USA. Questa società statunitense ha scelto la TTM Laser come partner tecnologico, acquistando un impianto FL 400 3D per tagliare tubi con diametro massimo 406mm. Qui di seguito l'articolo uscito sull'edizione di giugno 2016 della rivista The Fabricator.
Several years ago Dee Roskelley faced a challenge common to many in custom metal fabrication: Where to invest next? Roskelley is vice president of procurement and manufacturing technology at Richards Sheet Metal Works, a custom fabricator in Ogden, Utah. He knew the workhorse on the shop floor, a 5-kW CO2 TRUMPF laser with linear drives, was showing its age after a decade of service. About two years ago Richards’ owners called on company leaders for a new growth strategy.
Figure 1 Kevin Jones, vice president of sales and customer development (left); President Sterling Jensen (center) and Dee Roskelley, vice president of procurement and manufacturing technology, stand by Richards’ new tube cutting laser.
As Roskelley recalled, “We were challenged to think about where we would make the best gains.” The path seemed obvious: The fabricator needed new flat-sheet laser cutting equipment. Managers batted around ideas. Surely they needed a fiber laser, which could run circles around some of their old CO2 machines, especially when cutting thin stock. After all, laser cutting is the primary fabrication process; if that’s not working up to snuff, it starves the rest of the shop of work. But Richards isn’t a conventional custom fabricator. Walk into Richards’ facility today and you’ll see a 128-foot-long tube cutting laser. A monster of a machine, it can straight-cut up to 0.787-inch wall thickness, bevel-cut walls up to 0.625 in. thick, and handle work as heavy as 94 pounds per foot. The bundle hopper moves material up to 41 ft. long, with a maximum total weight of 10,000 lbs. Although the bundle loader can handle up to 10-in.-OD round tube, the shop can manually load lengths up to 45 ft., with a maximum round OD of 16 in., maximum square tube of 12 by 12 in., and maximum rectangular tube or I-beam at 8 by 14 in. Oh, and it can also cut tube as small as 1.5 in. OD. Installers had to shoehorn the machine into one of Richards’ facilities. They had enough space—barely (see Figures 1 and 2). So what gives? Why not buy a new flat-sheet cutting laser? For the answer, managers pondered the shop’s history: From the customers’ perspective, what changes would make the most difference?
Figure 2 Richards’ new 128-ft.-long tube laser can handle manually loaded workpieces—including wide-flange beam, channel, and angle—up to 45 ft. long. The bundle hopper can accommodate round, square, and rectangular tubes up to 41 ft. long.
Pushing the Envelope
They immediately thought of their decade-old 5-kW CO2 laser. “That [machine] really gave us an opportunity to reinvent ourselves with our current customer base,” Roskelley said. That machine allowed the shop to precision-laser- cut carbon steel up to 1 in. thick. Before Richards purchased the machine, many customers resorted to oxyfuel and plasma cutting the plate and then sending that plate to be machined to the required tolerance. It worked, but it was also expensive. When customers and prospects found that an Ogden fab shop could laser-cut plates to the required tolerance in one setup, the orders started flowing in, and Richards started growing. The company became known in the region for its ability to cut 1-in. plate cleanly and efficiently. “We had so much heavy plate work, our shuttle table had to be re-engineered, because it just wouldn’t hold up under the weight. We just kept running 0.75- and 1-in. material,” said Sterling Jensen, company president. “It was a good problem to have.” Customers couldn’t take their work elsewhere very easily, because few if any shops in the region provided Richards’ capability or level of quality. In other words, it wasn’t commodity work. Managers had this in mind when they mulled over a new machine investment last year. On the one hand, if Richards purchased a fiber laser, it could offer more competitive quotes on jobs calling for thin material. But the change wouldn’t be dramatic or unusual. Having a flat-sheet laser cutting machine by itself doesn’t set a shop apart anymore. On the other hand, for years customers had been asking Richards about tube fabrication. Shop engineers actually pushed customers away from tube and toward formed sheet metal and plate. But when tube made the most sense, the people at Richards made it work. For instance, the company fabricated a 6- by 12- in. rectangular tube with 0.375-in. wall thickness using a horizontal band saw and a high-definition plasma table. They removed the slats and replaced them with a fixture to hold the tubular workpiece. It wasn’t ideal, but it worked. The fabricator also cut tube manually on an old 2-kW laser (of late 1990s vintage), again using a custom fixture. It was a slow process, but cutting the tube in one setup was much more efficient and accurate than manually drilling holes and other features. “This experience had already opened up doors with our existing customer base,” Jensen said. When Richards purchased its 5-kW flat-sheet laser machine, it moved a lot of jobs from the high definition plasma machine to the laser. The market for thick plate laser cutting seemed wide open, with few competitors. The same could be said for large-OD tube cutting, though Richards managers also knew their custom fabrication niche. Ideally, they wanted to offer the widest range of tube cutting possible, from the very small to the very big (see Figure 3). They needed a machine that could cut both large and small-diameter tube, as well as open profiles like wide-flange beams and I-beams. And they found such a machine in Brescia, Italy, offered by a company called TTM Laser S.p.a. Richards chose one that was offered with a 4-kW CO2 laser from TRUMPF.
Figure 3 The machine can process an extremely wide range of material, cutting tube from 1.5 in. all the way up to 16 in. OD.
Making Old Machines Reliable and Productive.
From one perspective, pursuing a tube cutter seemed like a no-brainer. Managers knew they could transfer a fair amount of existing work to it. Most important, the massive machine would give Richards capability that few if any custom fabricators had. From another perspective, it was an incredible gamble. For one thing, the massive machine cost well into the seven figures. That’s a significant investment for any company and a truly massive one for a 96-person shop. Moreover, the company needed to maintain its bread-and-butter flat laser cutting work. Yet if the shop were going to make the leap into tube cutting, it couldn’t afford to buy a new flat-sheet cutting laser too. What if, after taking the leap into the tube world, its flat-sheet laser cutting machines deteriorated beyond repair? That surely would spell disaster. But expanding into tube fabrication was just one prong in Richards’ strategy. Another prong involved taking a long, hard look at their existing machines, how they’re maintained, and their true capabilities. It’s a common story: A fab shop manager reads a spec sheet, buys a machine, and then finds that—for real-life jobs—some operations he thought would be possible just aren’t, unless you have ideal material, or the machine is in absolutely perfect condition, or the beam is adjusted just so, or…Fortunately, six FABTECH®s ago, Roskelley met Brent Donner, who runs DLC Manufacturing and Fabrication Inc. in New Ulm, Minn., and also offers laser consulting services. Roskelley spoke to him about the challenges he was having with his aging 5-kW CO2 laser. “I saw him cut an inch-and-a-quarter material on the first try,” Roskelley said. “He was able to plug in the numbers out of his head: the speed, the gas pressure, the focal adjustment. And the part looked as if it were 0.75 in., the cut quality was so good. My guys about fell over.” For years Roskelley and other managers had been asking the operators to push the limits of the machine— nothing beyond the manufacturer’s recommendations, but close to them. They were always met with resistance. Roskelley added that he doesn’t blame the operators at all. The company had less than ideal preventive maintenance practices, so the machines weren’t in top condition. Working with equipment in this condition, operators—who strive for efficient, error-free production—of course didn’t want to push equipment too far. Donner offered training on achieving the proper beam alignment and other parameters, ensuring the beam has the right energy density in the right places to create a clean cut in thick material. On the 5-kW machine, Donner also recommended that the shop install a nitrogen generator not for the assist gas, but for the gas protecting the optics in the beam path. “He told us one secret is to keep your beam path pristine,” Roskelley said. “You don’t use bulk liquid nitrogen. You generate your own nitrogen for the beam path, and you protect it like no other.” He added that Richards traditionally has replaced the beam optics about once every two years. Since the shop installed a nitrogen generator for the beam path, it has yet to replace its beam path optics. Roskelley was told that such a setup may extend the life of the optics for seven years or even longer. “Now our old 5,000-W machine is actually running better than it was new,” Roskelley said, adding that this is thanks to proper maintenance and comprehensive operator training. Contracting with a third party for machine refurbishing, maintenance, and training wasn’t free, of course, but it was less expensive than buying a new machine (see Figure 4). The experience also made the Richards leadership team appreciate how valuable it is to really know a machine, inside and out. When the tube laser was installed earlier this year, Roskelley himself learned how to operate it and grew familiar with the machine limits as well as how far the system could be pushed. Meanwhile, Kevin Jones, the company’s vice president of tube laser sales and estimating, learned how to program it. The two don’t operate and program full-time, of course. But they know very well how the new tube laser functions, and they can step in when needed. “Dee and I are cut from the same cloth,” Jones said. “We both hate it when people say it can’t be done. Now, we’re always pushing the limit. There are things we didn’t think could be done, and we’re doing it now. Management is now involved in pushing the envelope, and that is really helping us grow the company.”
Eventually, no matter how well machines are maintained, they do wear out. That’s why Roskelley said the company will invest in a fiber laser before the end of the year. But now that the shop has pursued tube cutting in a major way, the growth options abound. “The funny thing is that we used to steer customers away from tube,” Jones said. “Now we’re steering them toward tube, if it’s a faster and more cost-effective option.” Jones added, however, that as Richards’ fabrication capabilities become more diverse, it’s careful to maintain relationships with its current customers, some of which are also custom fabricators. If an opportunity will take away current work from those custom fabricators, Richards won’t pursue it. Is tube bending or end forming machines next on the bucket list? It’s too soon to say—the tube laser was installed just several months ago—but sources said investing in such machines is a possibility down the road. At this writing, Roskelley said the company is not regretting its expensive plunge into tube cutting. Orders are flowing in, and some existing jobs have become much more efficient. For example, the company redesigned one mezzanine project around the tube laser, with structural components having tabs and slots to make them self-fixturing on the job site (see Figure 5). It took time to program, but the effort paid for itself and then some in the field. (Along with in-house fabrication, Richards also offers field fabrication services.) Another hidden benefit: Tube cutting has opened up significant capacity in rolling. The reason? For one significant job, Richards redesigned a component that was previously rolled on a plate roll and then welded. Now the product is cut complete on the tube laser. The tube material is twice as expensive, of course, but Richards is still saving the customer money, not only on a per-piece basis, but also in inventory. Previously Richards delivered about 200 parts a month, and the shop required several weeks of lead time; hence, the customer had to hold some buffer inventory. Now it takes the tube laser a minute and a half to produce one component. When the customer orders a batch of 200, Richards can have it ready in just two days. As Jensen put it, “This has helped [our customer] grow his business and helped cement our relationship.” When it comes to long-term growth, that kind of relationship is a central ingredient.
Figure 3 The machine can process an extremely wide range of material, cutting tube from 1.5 in. all the way up to 16 in. OD.