Fab Cutting Update: Laser and Waterjet
Article From: October 2020 Manufacturing Engineering, Ed Sinkora, Contributing Editor
FABTECH ‘Show in Print’ Targets New Technologies
What doesn’t happen in Vegas stays in our magazine. So, we bring you some highlights of the exciting advances in cutting you would have seen at FABTECH 2020 this year in Las Vegas, which has been canceled due to the COVID-19 pandemic.
Let’s start with laser—and punching. According to Jeff Tyl, North American sales manager for fabrication at Murata Machinery USA Inc., Charlotte, N.C., there are numerous combination machines on the market, mixing plasma cutting with drilling and tapping heads, or “Whitney-type machines that use punch and plasma, and turret punch presses with fiber and/or plasma heads.” But the new Muratec LS3015HL is completely different. “It’s a fiber laser first and foremost,” while also having impressive punch press capability, so Murata calls it an “advanced hybrid.”
The 6-kW laser can cut material up to 1″ (25.4-mm) thick, while the workholding on the punch side can handle up to ½” (12.7 mm), explained Tyl. So the machine is targeted at customers who would buy a laser, but also have secondary processes after cutting, like “marking, dimpling, drilling, countersinking, and tapping,” he said. “We’re talking about manufacturers of LED lighting, steel furniture, architecture, elevators, HVAC, medical devices, cabinets and lockers, food service equipment, aircraft parts and equipment, and computer electronics. … They are looking at going from metal stamping to fabrication, or already have some small turret kind of applications or small-run applications. [Applications include] people that need high production of very thin parts, or relatively thick production that can’t be done on a standard turret.”
Tyl added that the forming head on the punch side of the machine is “five-ton top and a five-ton bottom, so you can potentially punch up or punch down, and even at the same time for a combined ten tons.” That unit has eight positions for tooling, and users can add an automatic tool changer that holds up to another 50. The tapping head turret features eight live tools.
Both units ride on the same gantry and are servo driven, “so you can adjust the height and pressure, unlike a hydraulic press that goes from 0 to 100 without any variability,” said Tyl. “Our reposition accuracy is 0.001″ [0.0254 mm]. We can do countersinking with our drill and tap heads, adjusting the height so that when you put your screw in, the head lies flat. It’s almost like machining, to the point where the tolerance is so tight it’s better than most people’s standard cutting or secondary operations, because you only have to calculate where that sheet is once.”
That contrasts with cells that laser cut in one machine and then move and reposition the part in a machining center. “Our machine will do all the interior holes first, then do the interior forming and tapping operations, then move the material back over to the laser side to do all the large laser cutting operations and the outer profile,” said Tyl. “The material doesn’t move, so the positioning repeatability is very high. And it preserves the cosmetic appearance of all materials.”
Finally, depending on the processes and the need to move parts between machines, Tyl said Murata’s time studies indicate that the advanced hybrid can “save up to 50 percent of the total production time.” Plus it integrates with Muratec’s FN3015TL large-capacity, laser sorting stocking system, enabling hours of lights-out unattended production.That contrasts with cells that laser cut in one machine and then move and reposition the part in a machining center. “Our machine will do all the interior holes first, then do the interior forming and tapping operations, then move the material back over to the laser side to do all the large laser cutting operations and the outer profile,” said Tyl. “The material doesn’t move, so the positioning repeatability is very high. And it preserves the cosmetic appearance of all materials.”
Higher Throughput by Moving the Beam
At Amada America, Buena Park, Calif., the big news is the VENTIS laser cutting machine and its patented locus beam control (LBC). As Dustin Diehl, laser division product manager explained, LBC can move the beam within the diameter of the nozzle, roughly 0.040″ (1.016 mm) “in an infinite number of patterns. We can go side-to-side, figure eight, or sweeping motions back and forth—and it’s done in milliseconds with optics just above the head.”
In turn, these patterns can be tailored for different applications. “With our other fiber laser technology, we’ve learned that each material likes to be cut a little bit differently,” explained Diehl, “whether that’s beam diameter or depth of field.” But with that other technology, Amada adjusts the mode of the laser to cover different applications, which diffuses the beam. Whereas LBC “maintains a very high spot density and all that power throughout all the material thicknesses,” said Diehl, “and then we just choose the pattern for the desired goal.”
Amada offers three standard modes for achieving three different goals. “Quality mode” delivers superior edge quality for “a food grade application, or perhaps medical equipment, where cosmetic appearance is crucial and you want to avoid a secondary grinding or deburring operation,” explained Diehl. “Productivity mode” is designed to maximize cutting speed. And “kerf mode” opens up the width of the kerf to facilitate robotic part removal from the nest.
Diehl added that VENTIS is also unique in using a single 4-kW module to match the cutting capacity of higher wattage machines, even tackling 1″ (25.4 mm) steel plates and thick stainless. “And in doing so with a 4-kW single module, you’ll see about a 30 percent reduction in your overall electrical consumption.” Amada is able to deliver 4 kW with a single module because it designed and engineered the fiber power source, choosing what it says is the most powerful diode technology on the market. Diehl said the greater efficiency of the unit also comes into play when considering throughput. “In side-by-side comparisons with our previous generation 4-kW machines, we’ve seen overall processing time improved by 20 to 30 percent with the VENTIS.”
Active Speed Control Adjusts Laser Proactively
Trumpf Inc., based in Farmington, Conn., regularly releases patentable technology, according to Sales Engineer Brett Thompson. The latest is called Active Speed Control and it’s available on Trumpf’s high-end TruLaser 5000 series machines.
“In the past, a skilled laser operator would stand by the machine with a hand on the potentiometer,” said Thompson. “And based on the look of the plume, the sound of the frequency, and the light interacting with the material, that person would adapt the speed. If, for example, they saw some rust on the sheet they would slow it down a bit.” The problem with this approach is two-fold. Not only does it tie up a skilled operator all day, those folks are becoming rare. In fact, given the lack of skilled operators, the more likely reaction to a problem with the cut is turning the laser down to 80 percent and walking away, recounted Thompson. “That’s a huge complaint we hear from customers,” he said. “Their quotations are completely inaccurate and they’re not profitable, because the simple fix is to just lower the speed.”
So Trumpf moved to “build additional intelligence into the machine,” as Thompson put it. “As the name Active Speed Control suggests, it adjusts the laser feed rate. The laser looks at the shape of the kerf and adjusts in a proactive way.” This contrasts with competing systems, he added, which measure only a lost cut and react to that input. Such systems do slow down, or even stop, when they detect problems, but often not before the cut is lost, he said. “Reentries may be possible, but you’ve lost that part. And the problem can keep reoccurring if your machine is having some consistency issues, which could be due to something as simple as not maintaining it properly. Or, more likely, the material’s inconsistent. That’s certainly something that we struggle with in North America.”
Instead, Thompson explained, Active Speed Control records several images per second to determine what is happening to the laser beam in relation to the material in real time. “Information gathered in real time indicates whether we’re going too fast or we’re hitting some sort of condition in the material,” he said. “It could be a surface condition, like rust on the top. It could be in the chemistry of the material, maybe a little pocket of silicon or something. There are many little variations that would typically cause cut quality to be inconsistent, or to be outright lost.” Active Speed Control measures and adjusts to all those variations. It also adjusts to variations in thicknesses. But, because operators sometimes load the wrong materials in the machine, the system is set to prevent the laser from cutting the wrong gauge.
In Thompson’s opinion, the feature is most advantageous in steel “because steel tends to be the least consistent. It’s prone to oxidation and you have more surface issues. And there are so many different grades of alloys.” Active Speed Control is “definitely having an impact on how much material’s being scrapped,” he said. “But the bigger impact we’re seeing is an increase of about 7 to 9 percent in productivity levels. You’re not buying any more laser power. You’re not buying any more dynamics. You’re just allowing the laser to go as fast as it can reliably cut.” Active Speed Control also increases the feed rate over the baseline rate, which typically accounts for environmental factors like the operator not making sure that the protective glass or the nozzle are in perfect condition. If Active Speed Control “sees” that the cut can be sped up, it does so automatically.
Smart, High-Capacity Sorting
Given the incredible speed with which fiber lasers churn out parts, it’s easy for sorting operations to become a bottleneck. To overcome this holdup, MC Machinery Systems Inc., Elk Grove Village, Illinois, has introduced the ASTES4 LASORTING, a “single, integrated, multi-functional system capable of controlling the entire production process from loading, cutting, sorting, palletizing, and unloading through to the storage of the finished parts,” according to a company statement. MC Machinery Systems cites a study that shows a stack of nests that would typically take three people 2.5 hours to separate would take the ASTES4 only about 37 minutes, with every part arranged perfectly and palletized.
“This has even greater ramifications if things like grain direction or left/right part disposition are critical for subsequent processes,” said Jason LeGrand, laser automation specialist for MC Machinery Systems.
Besides the automated, smart programming required for such a feat, the system also boasts a Cartesian robot with a per-arm capacity of 1,100 lb (499 kg). “Other systems tend to be in the 100 to 250-lb range [45-113 kg],” said LeGrand. “We have four arms and two gantries. They’ve got one gantry and two arms.”
Do the math and note that the standard ASTES4 can handle a combined weight of 4,400 lb (1,996 kg). Maximum speed is 9,600 ipm (244 m/min) for fast sorting. LeGrand added that the end unit of each arm can rotate 360°, “to orient the part for any reason you might want to rotate it. We also have the option of an additional axis that will rotate up to 90º vertical.”
Plus, said Jeff Hahn, national product manager for laser, the system uses quick-change grippers so it can readily adapt to different material types, “like tools on a mill.” Hahn also explained that the system is modular and can be configured to meet different space constraints and production needs.
Bringing Peace Of Mind to Waterjet
Waterjet is newer than other cutting technology, but as with any fabrication machinery, waterjet customers are looking for reliability, versatility, and a solid return on investment. As Flow International’s Vice President of Sales Brian Sherick, sees it, “Waterjet is a solid addition to any machine shop that allows you to take on virtually any kind of cutting projects. Since we serve a broad range of customers, usage can vary from one shop or application to another, where one might run their system for a full workday, five days a week, and another may only run only a couple of hours a month. Regardless of how often a customer uses their machine, we want them to feel confident in every aspect of their waterjet’s capability and performance.” So for Flow International, Kent, Wash., the most important thing it could do is bring predictability and peace of mind to the industry by offering comprehensive preventative maintenance programs. They’re called FlowCare plans, and customers can choose from three levels of parts and service support to suit their operation.
“Historically, one of the challenges in waterjet has been uncertainty in the customer’s mind about how much will it cost to operate the machine, how to perform complex maintenance, and whether they can get all the service they need,” said Sherick. “So we’ve developed plans that answer those questions exactly. In other words, you may have a fixed investment amount that covers a certain set of consumables and all the maintenance for a certain period of time, so there are no unknown or additional costs for that term.”
Of course, Flow has engineered its machines to stand up to the ultra-high pressure water and garnet sand abrasive used in the waterjet process, both of which are very corrosive and aggressive by nature, explained Sherick. “With FlowCare, customers have a good handle on the service life of each component, so they know when to replace critical parts before failure. But the program’s success also depends on regular visits from factory certified technicians who make sure that the machines are running as prescribed, and not letting the machines run into failure,” said Sherick. He added that training is also important, because it both sets customer expectations and gives them the proper knowhow to get the most out of their system, “things like making sure they have the correct water quality and the proper utilities.”
Flow’s goal is providing a reliable, predictable process that elevates the image of waterjet, and it seems to be working. Sherick reported that over 80 percent of its new machine sales now include a FlowCare plan and “even customers that have been running machines for years without such plans have bought new machines with the plans and said, ‘You’re right. This makes sense. Keeping this thing up and running, and avoiding downtime is an absolute winner.’” The program is new, but it appears most customers who already have FlowCare are renewing their plans in growing numbers, Sherick said.