If you’re staring at a truckload or two of components that need to be welded and wondering how you’re going to finish them all before the end of the millennia, a custom welder might be the answer. Custom equipment might also be the solution for welds that are incredibly long, ridiculously heavy or situated in places no one but a small child could reach.
If neither robot nor human can consistently weld a complex part and if customers start complaining about quality levels, a custom welder could be the solution. In fact, there are so many good reasons to buy a welder that’s been customized to a specific application, you might wonder how you ever got by without one.
Resistance is not futile
Jim Dally thinks so. The president of Standard Resistance Welder Co., says it’s easier to justify investment in a custom welding machine than one might think.
“We used to say that you needed around 45,000 parts before automation made sense,” he says. “Today, with the way that we can take a standard press welder or small, multi-head spot welder and modify it, you can easily justify a special machine for as few as 15,000 parts.”
One example is a custom machine Dally built for an appliance manufacturer that was having problems attaching a tube to the end of a temperature sensor used in an electric stove. Where a human was not dexterous enough to position the parts consistently enough, Dally’s custom-built projection welder was able to “drop a complete part every two or three seconds.”
On the other end of the spectrum is an all-terrain vehicle manufacturer that needed to place 50 welds on a chassis measuring 4 ft. by 5 ft. at the tune of 65 pieces per hour. Here again, only an automated, custom solution would do.
“The decision to invest in a specialty welder comes down to the number of welds that are required and the sophistication of the finished part,” Dally says. “Whether you’re looking for greater throughput, part quality or any number of reasons, what’s important is that you have a good handle on your requirements before you enter into any custom machine project.”
What about R2D2?
But wait a minute – why not just use a robotic welder? Surely that’s a simpler, more flexible, more cost-effective solution than ordering a machine dedicated to a specific product. And besides, there are hundreds of suppliers that understand and can support a robotic welding application.
Wrong on several counts, says Dally. “Robots are fine as far as they go, but what if you have a part that needs 20 welds? Are you going to buy 20 robots? What about electrode wear? A single robot or even two robots working on the same part will need much more maintenance than a dedicated multi-head welder, and won’t even come close in terms of throughput.”
Maybe so, but what happens when the job goes away? Now you’re left with a machine that may have paid for itself early on, but at this point is headed for the scrap dealer.
“Around 40 years ago, we built a machine for a customer that got an order from Sears and needed to weld 25,000 table saw tops by Christmas,” he says. “It was supposed to be a one-time thing but lo and behold, they were still running it the next year and for eight or nine years thereafter. That’s just one more example of where a custom machine can really pay off. They recouped their investment many times over.”
Ironically, the table saw top welder did eventually make it to the scrap dealer. Dally bought it, salvaged it for parts and repurposed what was left for another application.
Bigger in Texas
Michael Sullivan, president of Texas Machine Tool International LLC designs and builds custom equipment for Fortune 500 companies. He says any of the projects his company works on have never been attempted before. Recent examples include a $750,000 welding machine for the oil and gas fields of West Texas and a “nanofiber” machine for a manufacturer of lithium-ion batteries.
“The welding machine uses a Fanuc CNC with linear motors and feedback from integrated load cells to control the welding force,” Sullivan says. “This was needed because the pipe has a lot of runout and it’s important to maintain consistent penetration. The result wasn’t 20 percent or even 30 percent better quality than that produced on the old machine; it was a 250 percent improvement.
“It’s obvious that people need machines to perform certain tasks, but when you can use the latest technology to build a machine that performs at this level, it’s not only extremely satisfying for us, but also makes a huge difference to those who asked for it in the first place,” he says.
Texas Machine Tool does more than one-off welding equipment and specialty machines. The company was founded on machine tool rebuilding, and Sullivan said that remains one of its core functions. But shops often request far more than “good as new” condition for their tired machine tools.
“Modifying used machines is really what led us down the custom equipment path,” he says. “For example, we were rebuilding a 30-year old Ingersoll lathe that was used to thread carbon graphite rolls. To improve throughput, we designed special tooling, mounted it to an auxiliary spindle, then set the machine up for thread milling. It was a huge improvement.”
Rebuilding and retrofitting machines provides many such opportunities to improve them. But leveraging these opportunities depends on the customer, on understanding their goals and making them aware of what’s possible.
“Quite often, there are ways to improve the design of standard new and existing CNC machine tools and welding equipment where inherent inaccuracies can be corrected through control or machine modification,” he says. “You just need to think outside the box.”