SuitCase™ X-TREME™ 12VS Wire Feeder Improves Flux Cored Welding, Reliability for Apex Steel

SuitCase™ X-TREME™ 12VS Wire Feeder Improves Flux Cored Welding, Reliability for Apex Steel

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Miller Electric Mfg. Co.'s SuitCase™ X-TREME™ 12VS features 425-amp output and allows Apex Steel, Inc. to run larger-diameter flux cored wires.
Published: February 1, 2008
Updated: November 1, 2018

Executive Summary

  • Flux cored deposition rates increased by 10-20 percent.
  • Suitcase-style wire feeder offers greater portability than sled-style feeders and better protects the internal components from harsh elements.
  • Soft start function gives the arc more time to become established and prevents the wire from stubbing into the weldment.

Miller Helps Build Lincoln Square

Apex Steel increases flux cored welding productivity with SuitCase X-TREME 12VS feeders

Apex Steel erected the steel for Lincoln Center from January to October, 2006.

When completed, the Lincoln Square Office Tower in downtown Bellevue, Wash., will house luxury residences and office space with breathtaking views of Seattle and Mount Rainer. Below the residences, amenities include a 16-screen luxury cinema, renowned eateries such as McCormick & Schmicks Seafood Restaurant and Maggiano’s Little Italy, home related shopping at fine stores like Hendreden, the corporate headquarters of Eddie Bauer® and offices for Microsoft® Corporation’s North American Sales operations.

Designed by Sclater Partners Architects and built by general contractor SKANSKA (phase I) and GYL Construction (phase II), the facility brings together world-class shops and restaurants, fulfilling the architect’s vision of “creating places people gather.”

Similarly, erecting the structural steel of floors 5 through 29 of Lincoln Square (phase II) brought together the team of Apex Steel, Inc. (, Pacific Welding Supplies/Tec Welding Sales ( and Miller Electric Mfg. Co. (

Apex Steel is a Puget Sound-based commercial steel contractor that employs approximately 100 ironworkers and a small office staff. Its successful approach to construction is based on strict schedule adherence, accurate cost control and a safe, motivated workforce (largely comprised of Ironworkers from Local 86). President and founder Kevin Koester, a union member since 1986 who still “carries his book,” built Apex Steel on the principles of integrity, quality and innovation.

April Finkbonner, Apex Steel, Ironworkers Local 86, and the SuitCase 12VS X-TREME engage in some “extreme welding” on Lincoln Center. To weld on the far side of this moment connection, she’ll stand in the aluminum “angel wing," 13 stories above the ground.

Maximizing Weld Deposition

One innovation Apex Steel uses to maintain its competitiveness is Miller’s new SuitCase™ X-TREME™ 12VS wire feeder. Designed to meet the demands of the construction welding market, the SuitCase X-TREME 12VS features a duty cycle of 425 amps at 60 percent duty cycle.

Miller’s previous model feeder had a duty cycle of 330 amps at 60 percent duty cycle, and some models of competitive feeders have an output of 300 amps at 60 percent duty cycle.

Duty cycle is the amount of time a voltage-sensing wire feeder or welding power source can weld out of a 10-minute period before needing to cool. A 60 percent duty cycle means that the SuitCase X-TREME 12VS can weld at 425 amps for six minutes, and then needs to cool for four minutes. At outputs of 300 amps or less, it can weld continuously.

Because the SuitCase X-TREME 12VS can weld at much higher amperages, contractors like Apex Steel can increase deposition rates by 10 to 20 percent or more when position and procedures permit welding at higher amperages. The chart below shows how an increase in amperage increases the amount of weld metal deposited per hour.

Typical operating procedures for 5/64-in. E71T-8 flux cored wire.

“The SuitCase X-TREME 12VS is a tool that helps us be more productive,” says Koester. “It also gives us the versatility to make full penetration welds on columns that are 300- to 400-lbs/ft, as well as make partial penetration welds on columns that are 150- to 200-lbs/ft. For example, we used this feeder on the Lincoln Square project, which has smaller welds, as well as for our recent work at Sea-Tac airport and Overlake Hospital in Bellevue, where the columns were larger.”


Wire Speed
























Welding Pressure

“The pressure to use the largest wire diameter possible and maximize deposition rates can be intense. Contractors that weld faster can bid more competitively and/or take on more projects,” says Bob Hankel, director of outside sales, Pacific Welding Supplies/Tec Welding Sales.

Not satisfied with the current wire feed solutions for the construction market Hankel involved himself heavily during the SuitCase X-TREME 12VS design process when Miller solicited his input. This included spending a week at Miller’s corporate headquarters in Appleton, Wis., working with the product development team.

“When we introduce customers to a new product, we want to be sure, hands down, that it is the best product available,” says Hankel. “During the development of SuitCase X-TREME feeder, we had a unique opportunity to control our own destiny and help create the right product for the market. We could speak for ironworkers, contractors and their equipment needs because our Auburn, Wash., store has focused on serving this niche market for more than 20 years.”

To run larger diameter wire prior to the development of the “X-TREME” model feeder, steel erectors favored a “sled style” feeder or made heavy modifications to a competitor’s portable feeder.

However, Koester does not prefer to use sled-style feeders because they are awkward to move around a job site, especially when walking on decking. When loaded with wire, they also require two people to carry. Further, sled-style feeders are much more susceptible to corrosive environments (like the Seattle area’s notorious rain) and to job site damage.

Koester prefers the portability offered by “suitcase-style” feeders, which feature a closed case that protects the wire and feeder components, as well as a carrying handle for convenience. Unfortunately, competitive portable feeders and Miller’s earlier models of voltage-sensing feeders lacked the higher output and duty cycle requirements to compete with sled-style feeders.  The design of these feeders also left room for reliability and serviceability improvements.

The 35-lb. weight (empty) of this portable suitcase wire feeder allows this Apex Steel Ironworker to quickly move along the decking on floor 9 of Lincoln Center. Sled-style feeders do not move as easily.

Extreme Redesign

When designing an “X-TREME” model feeder, Miller first sought to understand the market needs, soliciting feedback from the Ironworkers, small and larger contractors and companies such as Pacific Welding Supply/Tec Welding Sales. Their key requirements were:

  • More output to run larger wires
  • Easier to service and maintain
  • Superior durability and reliability

At the heart of the SuitCase X-TREME 12VS is a contactor rated for an output of a 450-amps at 60 percent duty cycle (a contactor is an electrical relay used to control the flow of power. Used for safety reasons, it keeps the gun “electrically cold” until the gun trigger is pressed, yet keeps the feeder powered up).

“Our job is to make sure clients have equipment that allows them to be competitive in their markets,” explained John Powers, outside sales representative for Pacific Welding Supplies/Tec Welding Sales. “Apex Steel needed to be able to run large diameter E70T-6 and E71T-8 wire. The Suitcase X-TREME 12VS leveled the playing field. Now they can remain productive and competitive on their welding costs.”

“We need to use reliable, portable equipment like the SuitCase X-TREME 12VS feeder,” says Kevin Koester, Apex Steel founder and president. “Good time management makes or breaks a steel erector.”

Koester adds, “On the Lincoln Square project, we paired the X-TREME feeders with Miller’s gas drives (the Trailblazer 275 engine-driven welding generator). They peak out at about 300 amps, which is a lot of power for a small gas drive. We run them pretty hard for welding with 5/64th wire.”

To run larger, “hard to ignite” wires, Miller incorporated a “Soft Start” feature. Standard run-in speed is 50 percent of the wire feed speed while welding. The Soft Start function, controlled by an easily accessible switch, slows run-in speed to 20 percent of welding speed. Soft Start gives the arc more time to become established and prevents the wire from stubbing into the weldment, a common problem with larger wires.

Easy to Service

"Improved performance” means something entirely different to a service technician like Todd Hildebrand from Pacific Welding Supplies/Tec Welding Sales. While the SuitCase feeder is tough, job site accidents do happen.

“If we have to replace something like a damaged case—and we did, because one customer melted one—it only takes about 15 minutes and one tool, a 5/16-in. nut runner,” says Hildebrand. “The SuitCase X-TREME is great from a servicing standpoint. Its chassis design—where all internal components lift out on a chassis—means we can replace the case in a quarter hour. With some of the competition’s feeders, a case change is a half-day job.”        

Ease-of-service is important because Pacific Welding Supplies/Tec Welding Sales runs a very thorough service check on all equipment when it comes in off of rent, as well as before it goes out again.

Service checks on wire feeders include inspecting common wear items like drive rolls, gun cables and liners, as well as weld test and load test them.

“We’ll fire up feeders and welders to make sure they work in the customer’s application,” says Hildebrand. “When our equipment hits their site, it’s ready to weld without failure. Contractors generally don’t shop on price alone. To them, prompt service, trust and reliable equipment means much more.”

The Trailblazer 275 welding generator provides 275 amps of flux cored welding output and fits into compact spaces, such as this hallway on the Lincoln Center project, At right is Robert Mecham, Apex Steel, Ironworkers Local 86 and John Powers, outside sales representative, Pacific Welding Supply/Tec Welding Sales.

The Ironworker Test

Confident in the performance and capability of the SuitCase X-TREME 12VS—especially because they helped design it—Pacific Welding Supplies/Tec Welding Sales first introduced Koester and his lead man to the feeder at their Auburn facility.

“We had them weld at 425 amps, and their lights just went off. They had never seen such power from a regular production-model feeder,” says Powers. “Apex Steel was ready to weld with the X-TREME because it put them on a level playing field with their competition.”

However, Apex Steel can only remain competitive if equipment functions reliably.

“A construction environment is inherently tough on equipment, and Ironworkers aren’t exactly known for being gentle,” says Koester.

The SuitCase X-TREME features a rugged polypropylene case, which the military uses to protect computers and other electronic equipment. Not only can the case withstand normal construction use, it can even withstand being run over by a one-ton pick-up truck (a test that literally crushes competitive portable feeders and sled-style feeders).

“Slide rails” along one side of the case allow the feeder to be dragged by the gun or power cable without damaging the case or causing dirt to pile up on control panel (while dragging a feeder by the gun or cable is not a recommended practice, it happens).

Inside the feeder’s case, the main circuit board is trayed and potted with a highly resilient epoxy, and all of the connectors are coated with electrical grease. This makes the feeder as impervious as possible to water, corrosion, metal shavings, dust and other elements that commonly cause failures in other feeders.

“The SuitCase X-TREME 12VS could fall off a truck and roll into a water-filled ditch. As long as it didn’t sit there too long,” says Powers, “you could pull it out and it would work just fine.” Powers isn’t about to risk recommending mediocre equipment because he is extremely aware of how important uptime is to Apex Steel.

“Time is a huge factor. That’s where a steel erector can make it or break it as a company,” says Koester. “If welding equipment breaks down, that can cause another remobilization of tools, manpower and work preparation at a new location. On a job like this, the labor costs alone are about $85 to $90 per man, per hour. That’s why we need to use reliable equipment like the SuitCase X-TREME. They’ve been used and abused, as have the Miller Trailblazers gas drives. Both are holding up well.”