High-mix, low-volume manufacturing is a fiercely competitive arena. Fabricators in that space compete on price, quality and turnaround time, but they’re also competing for labor – specifically skilled welders, which are tough to find. Tight margins and an even tighter talent pool, therefore, demand automation. And increasingly, custom fabricators are choosing automated fiber laser welding due to the many competitive advantages it provides.
Inherently, laser welding offers an incredibly flexible and accurate way to weld. It’s highly repeatable, which means less scrap and less rework even when parts change frequently. And, one system can handle a wide range of materials at different thicknesses with a variety of weld joints – an attractive capability when volumes per part are low. To truly get an upper hand, though, an automated fiber laser welding system needs intuitive programming, vision systems and adaptive control – technologies that deliver the easier and faster setups that fabricators need.
Modern laser welding systems, like AMADA’s FLW ENSISe, are packed with those technologies and allow operators to call up a part program in seconds, make a quick fixture change and start welding in minutes – a welcome shift from earlier laser welding cells that required dedicated tooling and long setup times. These advancements are making laser welding more accessible and effective than ever before – especially for high-mix, low-volume shops.
An overlooked benefit
Interestingly, fixturing is one of the first topics that Len Fioroni, laser welding product manager at AMADA AMERICA Inc., brings up when talking to customers interested in the benefits automated laser welding provides. The fixturing aspect of the process is often overlooked but is an area where even more benefits can be found.
“Anytime a person is considering any type of robotic welding cell, they have to think about how they’re going to fixture the parts,” he explains. “When people think about fixturing, they’re usually thinking about traditional fixtures where heavy plates are being milled and bolted together. But, for many high-mix, low-volume welding jobs, fabricators can make their own egg crate fixtures from sheet metal. Because all of our customers are sheet metal manufacturers, they already have the means to create these fixtures themselves.”
The “egg crate” fixture Fioroni is referring to is essentially a modular, grid-style fixture or jig used to hold parts in position during welding. The name comes from its resemblance to an egg crate – a grid or lattice of intersecting ribs or slots that create open cells. Fabricators can easily create these fixtures on their laser cutting equipment out of sheet metal that’s slotted and tabbed together.
Fioroni says that traditional milled fixtures, typically produced for MIG or TIG systems, are often designed to serve as a heat sink. The goal is to draw as much heat out of the part as possible. Laser welding, however, doesn’t impart as much heat into the process as MIG or TIG welding does, which in some applications, eliminates the need for a traditional fixture.
“Traditional fixtures are made from thicker plate,” Fioroni says. “When you’re putting heat into the part from the welding process, it transfers from the part into the fixture. It doesn’t reduce the heat-affected zone, but it does mitigate how much distortion that zone causes. With fixturing for laser welding, we’re more concerned about locating the part in the exact same position each time than we are about pulling heat away from the part, which is why thin sheet metal works.”
There are still plenty of applications where a traditional, custom-made fixture makes sense. Fioroni says it all comes down to the customer’s preference and the volume of work they do.
“An OEM that’s going to run a part for several years is probably going to choose something beyond an egg crate fixture,” he says. “They’re probably going to need something that’s more robust and perhaps something that has linear guides. They’re going to build one tool that they’re going to use for multiple parts and thousands of cycles.
“But those fixtures are typically fairly expensive,” he adds. “If a shop has less volume, that cost can be a big concern. And that’s why we always discuss fixturing early in the conversation. Some people just don’t want to spend that kind of money on a fixture for a small run; they’d be left with a tool they can’t use for anything else.”
For OEMs that require traditional fixtures, plenty of manufacturers specialize in that type of work. Beyond the need for robust fixtures that will last several years, some OEMs need pneumatics integrated into their fixtures that allow operators to put a part in place and simply press a button to lock it down. For those needs, AMADA has partnered with several custom fixturing companies to educate them on fixtures used in laser welding applications.
High quality, low skill
In some applications, however, a fixture isn’t even necessary. For short runs or prototypes, soft or flexible fixtures, such as clamps, can be used. For AMADA’s systems, quick tool tables accommodate a range of components like hold-downs, squares and quick bolts.
“With quick tool tables, you can build a setup on the table and not have to design a fixture at all,” Fioroni says. “This is advantageous for shops that are only welding 10 or 15 pieces at a time. Also, with its grid-style positioning, it’s easy to rebuild the setup when the work comes back around.”
Soft tooling saves fabricators a lot of time, but there can be downsides. Because soft tooling can introduce minor deviations in the part’s location, an operator has to physically correct the part’s position to ensure that welds will be accurate. In these instances, AMADA’s TAS and AI-TAS can help.
“Our TAS and AI-TAS can automate that part of the process,” Fioroni says, “and it’s that type of assistance that’s opening the doors to more high-mix, low-volume applications. Without having to rely on high-skilled operators as much, fabricators can produce accurate parts in less time and with less manpower.”
With the entry-level, semi-automatic TAS system, an operator places a part in the fixture and initiates the welding cell. Using a folder with images of the weld positions, the TAS system checks the part’s location before the welding process begins. If it identifies a deviation in the part’s location, the system will suggest corrections, which the operator will have to verify.
“It’s very informative and intuitive,” Fioroni says. “If the TAS system is confident that it’s correct, it’ll turn green. You’ll get a yellow if it’s unsure and red if it can’t make a determination. Yellows have to be looked at and then determined yes or no while red ones have to be checked manually.
“With an actual fixture, manual checks typically only have to be made on the first run, but with a soft tooling setup, then you’re probably checking every piece,” he says. “The AI-TAS system, on the other hand, is fully automated and has the ability to know that the corrections are accurate to process, so no operator intervention is needed.”
There was a time when the industry at large didn’t think that laser welding could be flexible enough for high-mix, low-volume welding, but advancements in automation and manufacturing software have turned skeptics into believers. AMADA’s TAS and AI-TAS are great examples of how those advancements are translating on shop floors.
“The biggest advantage is not needing a high-skilled operator to produce high-quality parts,” Fioroni says. “With TAS and AI-TAS, operators don’t need to know how to manipulate the robot at all. All they have to know is a little bit about the HMI and how to set up the parts. It’s all about reducing the skill needed to produce high-quality welds.”
Best solution available
Whether fabricators are benefiting from faster travel speeds; deeper, narrower welds with minimal heat distortion; or easier part fixturing, one of the biggest benefits of laser welding and AMADA’s FLW ENSISe, in particular, is that it requires less operator involvement. Point blank, the industry just can’t find the welders it needs.
“There isn’t a big influx of young people that are learning welding and entering the field, and almost a quarter of the professionals in the field today are approaching retirement,” Fioroni says. “But with our laser welder, the process is automated, and in some cases, you can increase your material processing range. You can weld steel, stainless, aluminum, brass and copper. And you can do that all with the laser welding cell and not necessarily need a high-skilled welder operating the machine to produce those very difficult welds.”
Overall, laser welding is helping shops increase their accuracy and expand the types of metal that they can process while also helping to solve the skills gap. And even more savings materialize after the actual welding is complete. In most cases, laser welding can eliminate any need for post-weld grinding and polishing. There’s no spatter involved and the process doesn’t put a lot of heat into the part, so the thermal distortion associated with traditional processes is eliminated.
“If you’re looking at robotic welding, you should look at the best process available, which is laser welding,” Fioroni concludes. “Laser welding offers so many benefits and our systems reduce the concern for fixturing. You can produce fixtures yourself or use soft tooling for setups right at the machine. Pair that with our automated vision system, AI-TAS, which corrects for any deviations, and you have a true fully automated fiber laser welding system.”
