When welding looks like an inside job

With the right incentives, shops may opt to bring welding operations, such as this MIG job, in-house.

Not everyone considers welding hip and high-tech. It's a dirty business, and that's part of the reason why many shops outsource the work. However, for some operations, bringing welding in-house makes a lot of sense. In fact, shops can often reap a number of timesaving, cost-saving, and quality benefits.

If a shop is considering the in-house route, it should take a look at why it sent out parts in the first place. Perhaps the shop didn't have enough skilled people on the payroll, or it didn't want to deal with weld spatter and smoke. Maybe part volumes were not high enough to justify the hiring of skilled welders or the purchasing of new equipment. And perhaps the simplest reason of all: The part could be outsourced for less than it would have cost internally.

These are all good reasons, according to Dennis Quinn, senior engineer and robotics arc welding applications manager at The Lincoln Electric Co., Cleveland. However, there are just as many incentives for bringing the work back. "For example, your company now makes higher volumes of the same product, making it more economical to weld parts in-house," says Quinn. "Or your vendor costs may have skyrocketed because your vendors are busy and can't find good help. This, in turn, could mean the vendor can't supply parts on a just-in-time basis." In some cases, shops may also have quality issues with their vendors.

But the best reason to bring welding operations back in-house, says Quinn, is that a shop gains control over its own destiny.

From a manufacturing standpoint, recommends Pat Carney, business unit manager at Miller Electric Manufacturing Co., Appleton, Wis., shops should consider their core competencies. He says they should ask themselves what they do well and then focus on the things at which they wish to excel.

Specific to welding, he suggests shops review how the welding operation fits into the flow of a particular production line. Does it cause bottlenecks? Is it a critical element? Is the weld critical enough to maintain complete control over it?

If it makes sense to bring welding operations in-house, shops should determine what processes they will be doing — MIG, TIG, or stick — and then match up the equipment. Manufacturers like Lincoln and Miller and their welding distributors provide help at this stage. They will ask a shop about its processes, how long operations run, what materials and material thicknesses are used, and so forth. They then marry the exact process to the correct equipment.

Better welders
Today's welding technology is easier to use and more efficient than ever before, reports Carney, which helps validate the decision to go in-house. "Initially, we had all types of knobs and whistles on the front panels of our most high-tech equipment," he confides. However, Miller found that all these options just confused the operator — even skilled welders had problems adjusting everything. So the company buried its technology behind a simple, straightforward panel with one knob for setting weld parameters.

Lincoln, too, has simplified its welding systems. But as simple as these machines look on the outside, they still tackle complex welding operations. "Our inverterbased power supplies are really synergistic systems," remarks Quinn, "providing flexibility and controlling such things as voltage, pulsing, and wirefeeding. In fact, with the equipment currently on the market, shops can get an optimum bead by changing the output characteristics of their power supplies for each combination of gas and wire they use."

Robotic welding cells, too, are easier to use and set up. Shops still need to know the basics of arc welding, but now programming is simpler. To boot, shops need only one or two people to set up and program a robot, while unskilled labor then tends the machine.

What's the cost?
Return on investment (ROI) is what sways most companies to weld in-house or outsource the job. Carney suggests shops obtain a quote from a vendor as a benchmark, then figure out how much it will cost to do the part inside.

The shop should take into account what welding equipment, consumables, gases, filtration equipment, and, if applicable, robots are needed for in-house operations.

Both Lincoln and Miller can help their customers determine ROI. For instance, says Quinn, Lincoln Automation analyzes a part, determines its cycle time, and then calculates payback using a software program.

"Not only can we estimate the cycle time, but we can tell you what equipment is necessary — what power supply, robot, and positioning equipment you need," explains Quinn. If a shop wants to do a more detailed justification, Lincoln can give it a copy of the ROI software program. The welding equipment manufacturer even fills in the cycle-time estimates and the cost of welding equipment and consumables. The shop simply plugs in its labor and overhead costs.

A question of automation
In many cases, shops may opt for automatic welding equipment operations. Robots overcome one of the biggest hurdles shops face: The lack of skilled labor. A single robot can do the work of 2 ¹ /2 people. And robots are taking over highly repetitive jobs no one else wants to do and making companies more productive. It is now possible for one welding engineer to program several welding cells from a laptop.

Also, training workers to operate robotic welding cells is fairly simple. Lincoln and Miller offer basic and in-depth training sessions. In addition, they can help shops quickly diagnose and solve problems that may crop up during production.

Another advantage of robotic cells is that shops can change parameters onthe-fly. "You can change the wirefeed and voltage at predetermined points. You can go from constant-volt (CV) welding to pulse operations and back. Whatever it takes to get the optimum weld on your part," comments Quinn.

Many shops use inverter-based welders in automatic operations. Although the equipment is basically the same as used in semi-automatic welding, the difference is that the robot has complete control over the weld. Welding programmers simply enter the wire type and size, the gas used, and whether they want CV or pulse welding.

Inverter-based systems give shops the flexibility to do several different operations in-house, including pulse welding. "If the shop has to pulse, it needs an inverter-based system. Pulsing produces less heat and penetration than traditional MIG welding," says Carney. Pulsing technology is, in fact, gaining ground in the automotive industry, where thinner, lighter metals are welded.

A case for in-house operations

While a robotic arm welds mufflers for Briggs & Stratton’s InTek engine, an operator removes the finished pieces and fixes new parts to the other side of the indexing table.

A robotic arm welds a tube to the muffler assembly, which is fixed to an indexing table.

When the Specialty Products Division of Briggs & Stratton, located in Milwaukee, became responsible for the manufacturing, design, and engineering of engine components for its parent company, it decided to expand its manufacturing and finishing services. The company, which previously outsourced all its welding, decided to weld a 6-hp InTek engine muffler in-house. But the muffler was made of two metal types and three metal thicknesses, making welds complicated.

"When we looked at the difficulty of the welds — involving variations in welding heat and travel speeds — we knew it was more efficient to get a robot and operators than to hire welders," says Rob Poehlein, manufacturing engineer. "With skilled welders being so rare, we felt automation was the best option."

Confirming the decision to automate, Specialty Products calculated a return-on-investment of less than two years and the creation of six new operator jobs for the company.

Specialty Products eventually selected the RDS-1400P robotic docking system from ABB Flexible Automation Inc., Fort Collins, Colo., with a Miller Electric Auto Invision welding power source. The RDS-1400P incorporates indexing or stationary tables, and it is pre-wired and interconnected for easy setup. The system includes a six-axis IRB-1400 robotic arm, an Auto Invision with internal control and pulsing capabilities, and a Miller CoolMate 4 water cooler.

To make automation integration simple for the customer, ABB referred Specialty Products to a local automation systems integrator, Machinery & Welder Corp., also in Milwaukee.

The welding process for the mufflers on the InTek line begins when the operator fixes two sets of parts comprised of a muffler assembly, a bracket, and a tube onto the indexing table. When the operator pushes a button, the table rotates and stops in front of the welding arm, which makes one ³ /4-in. lateral and two 2 ¹ /2-in. orbital welds to join the tube to the bracket and muffler assembly (using 035 solid wire and 90/10 Argon/CO2 gas). While the arm is welding on one side, the operator is unloading the welded mufflers and reloading new parts onto the other side. The whole cycle takes 90 sec (45 sec/muffler).

Machinery & Welder provided initial programming and operator training to be sure Specialty Products was prepared to use its new automated welding system.

"I spent two weeks of initial programming and then hours of sample production to make sure the welding was just right, " says Joe E. Campbell, vice president and qualification and certification manager, Machinery & Welder. His company provides technical assistance and service whenever it is needed, but Specialty Products now handles all programming internally.