Above: R&E Automated Systems replicates its customers’ remote laser welders so it can troubleshoot and dial every aspect of programming, setup and welding.
As fiber becomes cheaper, R&E Automated Systems keeps remote laser welding systems dialed in for automakers
May 2015 - As a part of this issue’s focus on all things automotive, we’ve turned our attention to fiber laser technology. Although fiber laser cutting has received nearly universal coverage—particularly with the advent of higher power, faster cutting tables—fiber laser welding is a different beast. Put simply, both laser cutting and welding with fiber lasers start with the same power source channeled through the same conduit. How the power is projected at the head determines whether the workpiece will be joined or cut. Taken a step further, remote laser welding, which enables welding metal up to a half meter away from the workpiece, results in a joining process that isn’t unlike something out of “Star Wars.”
Fiber laser welding presents a few more factors that make it more involved to implement. While most fiber laser cutting tables are built as one cabinet, ready to go once they’re plugged in, fiber laser welders require integrating a fiber laser with a robot and welding head. The industry isn’t quite at a point where plug-and-play fiber laser welding solutions are an option, as integration means there’s complex programming and tailoring to applications before any welding will happen. Even after a robot, fiber laser power source and welding head are connected and programmed to work, most end users need ongoing programming support as they don’t necessarily have such expertise in-house.
That’s where R&E Automated Systems comes in. Founded in 1999 and based in Macomb, Michigan, R&E is an engineering, automation and prototyping firm that comes in after the end users and integrators get set up with hardware and manages application-specific controller programming for laser processing. It supports integrators with advanced expertise—think of R&E as a third party automation consultant. It’s no surprise that its proximity to Detroit, less than an hour south, means much of its business comes from the automotive world.
Among the fiber laser welding solutions R&E supports are those with an IPG YLS-6000. The YLS-6000 is a 6 kw laser designed to share up to six fiber laser lines from one source, making it a flexible laser for demanding production environments like automotive, aerospace, and oil & gas. It’s one of several power options from Oxford, Massachusetts-based IPG Photonics.
Tim Metko, weld engineer manager at R&E, says most of the IPG fiber laser welding setups that R&E has supported to date have been for the remote laser welding of automotive doors, body sides and seat backs. Virtually all the support today has focused on the remote laser welding of such components in varieties of steels. Aluminum is coming, but there are some additional challenges on alloy selection and overall ease of weldability that need to be worked out before aluminum is remote welded across the board.
Remote laser welding involves welding a workpiece from up to a half meter away within a field of about 200 mm by 300 mm. The beam emits from a scanning head attached to the end of a robot. Bursts of sparks erupt from the workpiece as the robot seems to move slowly over it. It’s a fast, remarkable process that isn’t going away.
Automation for automotive
When Metko first began working in the laser business in the 1980s, fiber lasers weren’t around yet. “It was mostly CO2, and then we had flashlamp-excited YAG lasers, which weren’t as reliable or efficient as fiber,” he says. In the last 10 to 15 years, fiber has come of age. Arming robots with it has taken laser welding a step further.
Several auto OEMs are fiber laser welding galvanized sheet metal in doors, rail assemblies, uncoated steels in seat frames and more. For example, Chrysler is laser welding the galvanized sheet metal doors for the Dodge Dart, as well as the doors for the current Jeep Cherokee at the Toledo Complex in Ohio. Metko says some rail assemblies are being fiber laser cut and welded because “it’s the most accurate way to build the front end of a vehicle,” he adds. “Put a cutting head on a laser, slap it on a robot, and it’s a pretty flexible cutting tool.”
It’s no secret that the pressure to use aluminum as an alternative to steel has grown due to automakers responding to CAFE standards, which have them under the gun to boost average fuel economy. Using aluminum to reduce vehicle weight will be realized by developing and proving successful methods to use fiber lasers for remote and fixed optic laser welding of a variety of aluminum alloys. Fiber lasers lend themselves to remote welding because, to weld at a greater distance from the workpiece, a higher quality beam is necessary to make the weld at bigger focal lengths.
Remote laser welding is a viable option because fiber laser technology is getting cheaper, allowing more industries to deploy small welds quickly without excess heat and distortion, says Eric Stiles, applications manager at IPG Photonics. Stiles is based out of Novi, Michigan, home of IPG’s Midwest facility. A remote welding head can make five 20 mm welds per section when running full bore. Some remote welding setups have robots welding “on the fly,” where the robot and laser scanning head move in a synchronized motion to reduce overall processing time.
The solution of using a robot sounds simple, but dialing in the remote laser welding setups for different applications isn’t—the settings that will weld a door won’t work for a powertrain component.
“When you talk about big companies, they probably don’t have skills or experience to operate this equipment. So, they’re interested in working with a contractor like R&E to set up the process, program it, adjust it and provide training to plant personnel,” Stiles says.
Aside from managing remote laser welding setups, R&E trains the companies it works with both on-site and at its own facility. Metko says one of the biggest challenges is getting operators at companies to understand how the IPG laser works, not to mention how to program the robot and scanning head.
“It’s three pieces you need to understand,” he says. “That’s where R&E gets a lot of its business.”
Remote laser welding essentially is replacing conventional spot welding, which has been used for about 100 years. Lifers in the existing automotive workforce are used to spot welding and programming its controllers.
R&E has its own remote (and static) welding setups in its development lab intended to replicate a customer’s setup so that it can train operators or troubleshoot. There, R&E has a 165 Fanuc robot, a HighYag RLSK head and IPG YLS-6000. It also supports programmable focusing optics (PFOs), but “the industry is standardized on the RLSK,” Metko says. R&E develops automation there for the Big Three and tier one suppliers.
“Some tier one suppliers come to us with prototypes they need to produce. We’ll program them offline, run them in our lab, take those same programs and deploy them in their plants. With the IPG laser, we use that lab to do development work for these guys before they get ready to go into production,” Metko says.
For aluminum, R&E experiments with settings like power, angles, speed and focus to determine what works with certain alloy types. In tinkering with the right combination of laser processing parameters, R&E can hone a robust welding process around aluminum. The company does the same work with high strength steels. With one fiber laser, R&E can use it in multiple cells to weld, cut and braze.
As manufacturing takes to remote laser welding, training will be key. The technology’s improved quality, lower costs and faster throughputs are only realized when the minds programming it are likewise equipped.
For many manufacturers, this is new technology that requires education first. “This is going to be an education process for the next decade,” Metko says. FFJ