Metal Connection, LLC Saves Fuel and Reduces Noise Output with New Bobcat™ 250 EFI on Scoreboard Demolition and Construction in Memphis | MillerWelds

Metal Connection, LLC Saves Fuel and Reduces Noise Output with New Bobcat™ 250 EFI on Scoreboard Demolition and Construction in Memphis

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New engine-driven welder generator with electronic fuel injection (EFI) helps reduce noise and fuel use on downtown stadium project; strong generator output runs plasma cutters and other tools. PLUS: Plasma cutters in construction/demolition applications.

Metal Connection, LLC Saves Fuel and Reduces Noise Output with New Bobcat™ 250 EFI on Scoreboard Demolition and Construction in Memphis

Metal Connection Scoreboard 2 lead.jpg

To kick off the 2012 season, the Memphis Redbirds — AAA affiliate of the St. Louis Cardinals — unveiled a brand new 3,600-square-foot scoreboard in right-center field at AutoZone Park. The new scoreboard, comprised of 36 10-x10-foot panels, is supported by more than 42,110 pounds of new steel and is now the largest video scoreboard in all of minor league baseball.

Chris Cramer, owner of Oshkosh, Wis.-based Metal Connection, LLC, worked on the demolition of the old scoreboard, as well as the steel fabrication and erection of the new structure over a six-week period in early 2012 (subcontracted through Madison, Wis.-based Stubblefield Sign Group). During that time he put the new Bobcat™ 250 EFI (EFI = electronic fuel injection) from Miller Electric Mfg. Co. to work as both a welder (Stick and Flux-Cored processes) and industrial-strength generator (grinders, plasma cutters). The newly redesigned Bobcat 250 EFI provided Cramer with a number of important benefits, including sound reduction, greater fuel savings (which lead to overall cost savings of about $100/week when considering extended run times and refueling trips), and greater generator power output for running tools on site.

Demolition work puts generator power, plasma cutter to test

Before Stubblefield and Metal Connection could build the new scoreboard, they had to tear the old structure down. Cramer began methodically cutting away catwalks and slicing the old scoreboard panels up into pieces small enough to be trucked away for scrap. To do this, Cramer relied on the Spectrum® 625 X-TREME™ plasma cutter, a 21-pound inverter capable of running off of 120- or 240-volt power with the exclusive MVP™ multi-voltage plug (see sidebar). This flexibility allowed him to cut a wide variety of materials and thicknesses, including the ability to sever material up to 3/4-inch thick1 when running the plasma cutter off of the 240-volt power available on the Bobcat 250, and cut up to 3/8-inch mild steel when running off 120-volt power in the man lift.

“We were cutting 1/4-inch steel plate at a lot of different angles for the demolition,” explains Cramer. “We were cutting a diverse amount of materials, from thin aluminum panels to I-beams and heavy steel plate ranging from 1/4 inch up to 3/4 inch. We had to move at a rapid pace and we never had an issue. Cutting performance is outstanding.”

Whether or not you can run a plasma cutter off of an engine-driven welder generator is an often-asked question. The Spectrum 625 X-TREME requires approximately 7,000 watts to start and run the machine at rated capacities, and requires increased power input as you work to cut and sever thicker materials. EFI engines, like the Kohler-powered, 23-HP EFI engine found on the Bobcat 250 EFI, optimize the air/fuel ratio for all engine speeds and engine loads, resulting in better performance compared to carbureted models. That better performance raises generator output rates to 12,000 watts peak/10,500 watts continuous, more than enough power to operate the plasma cutter.

“With the electronic fuel injection, there is an additional 1,000 watts of actual generator output power,” says Cramer, “which comes in handy when utilizing the Spectrum 625 plasma cutter. You have increased cut capacity. You can utilize the machine to its full capabilities running off of a generator power source. We haven’t had any issues as far as output, and that’s even with running extended cables going up to the top level of the scoreboard.”

That 12,000 watts of peak power is entirely usable for a minimum of 30 seconds — what Miller calls Accu-Rated™ — and is ideal for starting and operating maximum generator loads. The ten-degree skewed-rotor design further optimizes the generator with smooth power for better performance.

“Running the plasma cutter, there’s basically no difference whether you’re plugged into standard shop power or the generator on the Bobcat 250 EFI,” says Cramer. “It’s clean and excellent power with no difference in performance.”  

Welding work showcases flux-cored, stick capabilities

Cramer and his team fabricated the structure of the new scoreboard in sections on the ground that were then lifted and welded or bolted into place. The structure features seven total platform levels split into two separate sections, making 14 individual sections that required fabrication. Cramer relied on Self-Shielded Flux-Cored welding — a process that requires no shielding gas and is ideal for construction applications for its ability to provide strong welds in outdoor conditions where shielding gas could be blown away.

“We were running .045-inch E71T flux-cored wire for the actual platform welding with the SuitCase® X-TREME™ 8VS wire feeders, which gave us the portability to move around and build the platforms on the ground itself,” explains Cramer. “We were working with 4-by-4-inch 5/16-inch-wall tube and 6-by-6-inch 5/16-inch-wall tube to fabricate the platforms and the catwalk structures. Flux-Cored welding helped to speed up the process.

Flux-Cored welding provides a number of benefits in construction applications: it is an all-position, multi-pass process with good impact properties, even at low temperatures. Flux-Cored welding can replace and improve productivity over 7018 Stick welding in applications such as this. Flux-cored wires offer a higher deposition rate and deposition efficiency than Stick electrodes, which helps to lay more wire faster and with less waste. The Bobcat 250 EFI offers 17 to 28 volts of output power when matched with a wire feeder for Flux-Cored welding, and its constant voltage (CV) output provides superior wire welding performance versus a constant current (CC) machine. A simple weld process selector dial on the front of the machine, as well as a range control dial with two options for wire welding helps simplify operation.

“It was excellent in terms of the ease to set up, switching polarities, and setting-up the wire feeder directly to the unit,” says Cramer.

Once each platform was fabricated on the ground, Cramer then switched over to the Stick welding process with a 5/32-inch 7018 electrode. He’d stage the Bobcat 250 EFI on each platform on the way up as he welded each section and the associated catwalks. Like Flux-Cored welding, Stick welding is ideal for outdoor applications as it’s a self-shielded process that requires no shielding gas or associated equipment, and it doesn’t require the wire feeders associated with Flux-Cored welding. Similarly, the Bobcat 250 EFI offers easy setting capabilities that help the operator simply select the process and electrode diameter, and then fine tune the amperage within the suggested output range.

“Because we were up in the air, it made it easier to negotiate getting around with Stick,” says Cramer. “We’re able to stage the machine right next to us on the platforms and bounce around with our cables.”

Bobcat 250 EFI offers noise reduction, fuel efficiency

One of the key operational benefits of the new Bobcat 250 EFI is reduced sound output (by as much as 33 percent). The new Bobcat 250 EFI has rotated the engine toward the front to create more efficient airflow compared to previous models, resulting in significantly quieter operation. This was critical on this jobsite, as it helped improve communication and reduced noise pollution to neighbors who live mere feet from the downtown stadium.

“As far as the sound output levels being reduced, this site is a perfect example,” says Cramer. “Having the decreased sound level is very significant to me as far as being able to communicate verbally with other guys as the machine is running, which it does all day. It makes it significantly easier to communicate. We’re also working in a very tight space where you have apartment buildings no more than 20 feet away from us. The last thing the neighbors want to hear is a generator running full bore first thing in the morning.”

As previously mentioned, electronic fuel injection eliminates the carburetor and provides an optimal air/fuel ratio for all engine speeds and engine loads, resulting in lower operational costs, fewer emissions, longer run times and better performance. It also eliminates the choke — a common nuisance to anyone who starts an engine-driven machine on a regular basis.  

“One of the first things I noticed right off the bat is that it’s nice initially starting the unit without having to pull the choke and mess with that,” says Cramer. “Basically, you flip the switch and it’s up and running.”

In terms of cost savings, the greatest benefit electronic fuel injection provides is fuel savings. Matched with a large 12-gallon fuel tank, welder generators with EFI help drive down operating costs not only from pure fuel savings (up to 27 percent over carbureted models), but extended run times that ensure more time welding and less time filling gas cans.

“The fuel savings have been great in terms of having to refuel,” says Cramer, "and the downtime that creates, the extended run times out of the machine — you can get a day-and-a-half to two days of actual runtime out of the unit before even having to be concerned about refueling.”2

On pure fuel savings alone, tests show that EFI fuel economy will save operators up to $1,000/year under normal use. That fuel economy and associated extended runtimes allow operators to go longer between refueling trips which, depending on where you’re working, may be a serious hassle.

“We don’t have a bulk tank here because there is limited space,” says Cramer. “We actually have to drive to a fuel station, refuel cans, then come back here and refill the machines. So having electronic fuel injection saves more than just the fuel itself, it’s the time and downtime and the refueling and the travel to do it.”

When Cramer factors in all of the effort and hassle that goes into refueling his machines at a site like this, a more total picture of cost savings related to fuel use comes into focus.

“I would say the savings are about $100 each week,” says Cramer, “when you consider my time being absorbed to leave the jobsite and travel to the refueling station, to refill the containers, to come back and stage the containers to refill the generators.”

Added performance, cost savings injected with EFI

Additional benefits noted by Cramer to the new Bobcat 250 EFI are a reduced size and footprint (5-inches shorter and up to 55-pounds lighter than previous models), centrally located maintenance ports for easy access, and reduced emissions (27 percent less CO and 33 percent less HC+NOx) that will improve the quality of the air in the work environment. All together, as a total power source for Cramer’s brand of mobile fabrication, the Bobcat 250 EFI adds up to be an efficient machine that will save him money in the long run.

“Being a more compact machine, with less sound, greater generator output (compared to a carbureted model), ease of service, fuel savings, all of the features add up,” says Cramer. “In today’s standards, EFI is a much more efficient way to run.” 

SIDEBAR: New Spectrum® 625 X-TREME™ Proves its Worth in Construction/Demolition Application

A 21-pound plasma cutter no larger than an average lunch pail isn’t the first tool you think of when you think of demolition (that would be a long-boom excavator or a wrecking ball), but Chris Cramer, owner of Metal Connection, LLC, has put the new Spectrum 625 X-TREME with new XT40 Torch to work on the recent demolition of the old scoreboard at AutoZone Park in Memphis. For a mobile fabricator like Cramer, the ability to have this much cutting power in a small package (it is rated at 5/8 inch when cutting at 40 amps off of 240 volt input power) is a significant benefit.   

“Having this being a small, compact unit like this, it doesn’t take up too much space,” he says. “People would be extremely surprised about what you can do with a small machine like that. It’s impressive how, when they changed over to the inverter series, the amount of output power in such a small, compact unit like that, you’d never believe you could do a project of this scale with such a small compact unit.”

“When we were doing the demolition, we were way up top and trying to get in these small spaces to do what we had to do, and the last thing you want is a bulky, heavy piece of equipment to move in and out of the man basket when you’re 80-feet up.”

Two major benefits Cramer called attention to in addition to the compact size were the redesign of the torch and the ability to plug into either 120- or 240-volt receptacles with the exclusive MVP™ (multi-voltage plug) adapters. Cramer claims the new flexible cable and the ergonomic design of the XT40 torch help simplify operation.

“A lot of times, you’re cutting in confined spaces or you’re having to maneuver around other equipment,” says Cramer. “With the new torch configuration, the lead is much more flexible, it gets into tighter spaces, it’s easy to untangle, and you don’t have the mess of having a really rigid torch assembly.”

The MVP plug further gives him the flexibility to get his work done regardless of what options he may have for input power.

“Having the ability to switch out plugs and find the voltage that’s suited for you depending on the material you’re cutting or the location you’re in, whether it’s off of 110-volt power out of the man-lift basket, 80-100 up in the air, or being able to use the 240-volt output power off of your Bobcat engine-driven welder generator. You can adapt it to any circumstance you may be in.”

1 Rated cutting capacity when running off of 240-volt power is 5/8 inch at 13 inches per minute (IPM). Maximum sever capabilities on this machine is 7/8 inch at 5 IPM.

2 Results will vary based on application and extent of use.