May 1, 2009
Over the past several years G&W has ramped up its robotic welding operations to the point where the company offers 2,500 available welding hours every week.
G&W Products is in an unusual situation. It's growing.
The Fairfield, Ohio, metal fabricator is on track to achieve year-over-year growth between 2008 and 2009—a rare feat these days. The shop's 120 employees work over three shifts within 112,000 square feet of manufacturing and warehousing space. They provide a full range of fabrication services for such industries as material handling, military hardware, retail displays, power distribution, and construction equipment. Capabilities run the gamut of metal fabrication processes, from laser cutting, stamping, and forming to tool and die work.
The company has more than 25 presses from 30 to 600 tons, with straight-side bed sizes up to 60 inches deep by 144 in. long. Its metal forming operations are able to process carbon steel, aluminum, galvanized stainless steel, copper, brass, INCONEL®—the list goes on. The company offers fast turnaround for made-to-order products in the store fixture arena, a sector with a need-it-yesterday reputation. Workers process aerospace hardware to MIL-I spec. The company offers hardening and coating, and uses statistical process control (SPC) to ensure quality and traceability. It provides complex subassemblies for railcars, including side posts, ladder stiles, beams, angles, supports, corner caps, cross ridge braces, draft carriers—again, the list goes on.
So how is G&W finding success in such tight economic times? Besides diversity—both in markets served as well as in processes and services offered on the floor—automation has played a big role. "There is no question robotic integration has allowed G&W to be more competitive in the marketplace," said CEO Gary Johns.
Over four years the manufacturer has ramped up its robotic welding offerings to the point where today G&W offers customers more than 2,500 available welding hours each week in gas metal arc welding, gas tungsten arc welding, and spot welding. Its equipment includes five GMAW robotic welding cells that process about 20,000 parts a month (see Figure 1 and Figure 2).
As the well-documented shortage of skilled welders continues unabated, the market for welding robots continues at a record clip: A June 2008 report from the International Federation of Robotics noted that the supply of robotic welding systems in North and South America increased 42 percent over the previous year. That's all well and good, but it doesn't reduce the need for welding knowledge, a fact G&W managers do not take lightly. Its highly skilled team of 20 welders has an important role in the company's production process.
Two elements, sources said, make up G&W's success in welding. First, managers know how to route parts through the most efficient process, be it manual or automated. Second, they know how to identify welding talent. Knowing who to put with what technology, manual or automated, plays a big role in G&W's success. Boiled down, it's about managing technology and people (see Figure 3).
"Most items we are welding robotically can be manually welded," said Randy Sagraves, the company's vice president of sales. "The factors driving us to robotic welding are related to cost and capacity, rather than capability. Volume is the most important variable in determining a fit for robotics. With some parts, we make several hundred pieces of a particular item each month, so it makes sense to weld it robotically. This allows us to be cost-effective by spreading the cost of the equipment and the fixturing over the cost of the job, while involving our highly skilled welders with jobs of varying volumes or items that are too large or complex for the robotic cells."
The robotic welding area features three System 50HP dual-headstock robot cells, a System RCT TurnTable robot cell, and a System 40 TurnTable cell from Lincoln Electric Automation with fume exhaust hoods. Robot arms are from Fanuc.
"Our robotic line handles MIG welding of aluminum parts, high-tensile-strength steel, and weldment geometries that require creative fixturing," said Doug Keehn, G&W's director of advanced manufacturing. "Once the fixture is proven out and the programming is completed to meet these challenges, the production and quality are quite consistent."
The dual-headstock workstations, designed for medium-sized parts, can reorient parts if the joint geometry calls for it—something that fits well with G&W customers' varied part orders, which can include structural, plate, tubing, sheet metal extrusions, and special shapes."These cells can handle our larger, more complex parts," Keehn explained.
The company's indexable, two-position turntable systems work well for G&W's small and medium-sized parts that can be welded without reorientation. For higher-volume jobs involving medium-sized production parts, programmers use the RCT robotic welding and cutting workcell featuring a center-mounted positioner designed to maximize the robot's work envelope.
The contract manufacturer's robotic systems hinge on two elements: quick setup and programming (see Figure 4). "If a part requires only a few welds, we can get sets of eight to 10 parts completed in two minutes," Keehn said, adding that "every robotic cell has two stations. While one station is welding, we can load the other side with the same part or a completely different part, provided the filler metal and gas are the same."
G&W managers recognize that both robotic and manual welding require specific skill sets. On the robotic side, mechanical engineering comes into the picture when designing complex fixtures. Those fixtures are critical to the success of each product. They must be accurately designed and programmed to hold tight tolerances, easy to load and unload, designed to hold as many parts as possible, and robust enough to withstand the rigors of consistent use.
The company relies on its trained programmers for this. Some programmers are journeymen welders, while others are automation experts who know how to run the equipment and program workcells for maximum weld quality, consistency, and speed. These programmers also receive weld training so that they can recognize good weld penetration and quality.
"Our programmers' backgrounds are varied," Keehn said. "When we identify who is best-suited to run the robots, we realize they might require additional welding training, or they might need training on the equipment. It requires both skills. You don't' necessarily need to have a welding background, but you do need to have a strong knowledge of good welding and programming, and know how to manage those cells to deliver a superior-quality weld. We're not just welding sheet metal. Our work involves many different aspects of welding."
According to sources, welding robotics shouldn't be mixed with simply trying to replace skill a shop can't find. Ultimately, welding automation is the same as any other manufacturing technology: it's about efficiency.
"Efficiency is an overall theme," Johns concluded. "We're looking to become leaner, more flexible, and more competitive. Robotic welding fits perfectly into this plan."