By: Ken Stanzel, product manager, Miller Electric Mfg. Co.
If a manufacturer of luxury motor homes takes the extra care to use cabinets with dovetail drawers and mortise-and-tenon doors, imagine the attention focused on the welds that hold together these 25,000 lb., 40 ft. vehicles.
“People’s lives depend on the welds in our chassis. I can’t stress enough how critical quality is. And to make a quality weld, we employ qualified operators and purchase quality equipment. Using Miller Electric welders helps us satisfy our customers and helps grow our business,” says Paul Freet, welding operations supervisor for Monaco Coach Corporation’s Wakarusa, Indiana facility.
These days, “grow” is the operative word at Monaco, which manufactures Holiday Rambler motorhomes. With sales exceeding manufacturing capacity, the company wanted to boost production to 25 units a day, up from nine per day. Monaco/Holiday Rambler doubled manufacturing space in Wakarusa to 483,000 ft., built a new paint and final finishing facility, and plans to open the third line which will produce gas motor homes, adding to the current 450 employees.
Steel Monocoque Chassis
Monaco/Holiday Rambler also expanded its existing inventory of 82 MIG welders when it purchased 42 Miller Deltaweld’ 302 welding power sources paired with Miller’s 60 Series wire feeders.
While most motor home manufacturers design or modify their coaches to a pre-built chassis design, Monaco/Holiday Rambler does not. It constructs each vehicle – “the whole shooting match,” Freet says – from the axle on up. For greater strength along the entire length of the chassis, Monaco/Holiday Rambler uses 1-1/2 in. diameter steel tubing to create a true, triangular trussed semi-monocoque frame (monocoque means that the body of the vehicle is integral with the chassis). Heavy duty rectangular I-beams cross-brace the chassis platform. Steel thickness ranges from 1/16 in. to 1/4 in. for most parts (tubing, walls, accessory parts). Some of the load-bearing parts in the chassis use 3/8 and 1/2 in. steel, but these parts are built at the company’s nearby Elkhart, Indiana facility.
For joining steel, the Wakarusa facility strictly uses .035 in. diameter wire and a 75/25 argon/CO2 shielding gas.
“It meets our needs, and it’s a lot easier to keep track of inventory this way,” confides Freet. Once the welding operators set up, they spend more than half their time with the arc on.
While Freet has worked with several competitive products and other Miller three-phase power sources, he felt the Deltaweld best suited his needs because of its simplicity, durability, energy efficiency and competitive pricing. Monaco/Holiday Rambler maintenance technician Bud Grooms elaborates.
“Whenever I need a new welder, I go straight to my Miller distributor, David Absher of Holox,” he says. “It was the best thing we could have done. Right away we knew the Millermatic 185 was the right choice for our applications.
“When Miller simplified the design of the Deltaweld [in 1995], they improved its durability with things like Fan-on-Demand,” he says. “If the welder doesn’t need cooling, the fan doesn’t run. It doesn’t suck in dirt all the time, and it’s quiet.” Fan-on-Demand reduces the amount of air-borne contaminants pulled through the machine, keeping internal components cleaner. Further, the Deltaweld’s reusable air filter easily attaches and detaches from the front of the power source. This reduces maintenance and extends service life.
Keeping the internal components clean, especially for the company’s older, non-Miller welders used to be a problem. Dust from the shop would get behind the control panel and parts would begin to corrode, especially the rheostat for the voltage adjustment. Cleaning did not work well because the machines then had a tendency to lose a phase (i.e., drop a leg of the three-phase power), which would burn out rheostats.
“I want to put a welder in and forget about it, not purchase replacement rheostats in lots of five for $300 apiece,” Grooms says.
“I’ve been around enough welders to appreciate the differences in the new Deltawelds. They hold up a lot better.”
Like any plant adding floor space or equipment, considering power availability and the expense of installing new power concerned Monaco/Holiday Rambler. Fortunately, the power efficiency of Miller welders helped dispel those concerns.
“I found out how little primary amperage Miller welders draw in another one of our plants, which has 208V power,” Freet says. “I could run a Miller on a 30 amp breaker, but a competitive welder required a 50 amp breaker under certain conditions. We never could have run the competitive machines because of that plant’s power limitations.”
The new facility housing the 42 Deltawelds uses 480V power therefore, breaker size is not a large issue. However, the Deltaweld’s approximately 10 percent power efficiency advantage is. Because a Deltaweld draws less primary power than any competitive machine in its class, each Deltaweld* reduces Monaco/Holiday Rambler’s utility bill by hundreds of dollars per year.
Note: Applies to power sources built after 1995, which feature an improved transformer design.
Premium Floor Space, Aluminum Siding
At the Wakarusa plant, the power sources and wire feeders hang from the ceiling [see photo], utilizing floor space more efficiently.
“It works best for us because of the versatility,” explains Freet. “The feeders are on trolleys that move back and forth to reach from one end of the bay to the other. We move the units side to side or forward to back. It’s a nice safety feature – there are no cables and hoses to trip over – and it’s easier to clean the floor. It’s like the Deltaweld: a lot less parts and less worries.”
In addition to the Deltawelds and 60 series wire feeders suspended from the ceiling, the Wakarusa plant also suspends Miller’s CP 300 power sources and XR-A push-pull wire feeders for welding aluminum.
Except for one model, Monaco/Holiday Rambler uses aluminum frames for the side walls of its motor homes. The company’s brochure even touts its Alumaframe® construction: The Alumaframe C-channel uprights and cross members interlock, running the full length and height of the coach. Each intersection is double welded [see photo]. This interlocking system is lighter yet stronger than the butt welded tubular framing some competitors still use – and the joints don’t break.
Many companies favor Miller’s CP welders for welding aluminum (and stainless or other difficult to weld metals) because they offer superior weld quality. The operator can fine tune the arc characteristics, this improves weld bead appearance.
Welding supply distributors depend on Miller to ship equipment quickly, and customers rely on their distributor for fast, convenient service. However, an order for 42 Deltawelds – and a request for delivering 25 of them doesn’t occur every day for a distributor.
“The equipment order from Monaco/Holiday Rambler came suddenly, but we had no trouble filling it,” says distributor Fred Gaboury, Mittler Industrial Gases and Welding Supplies, Elkhart, Ind. “We get a shipment from Miller every week, and on this occasion Miller arranged to have all arrive on its own special delivery.”
“Miller and Mittler meet our demands, so we can meet our customers needs. That’s what keeps us all in business. Together, we’re going to new horizons,” concludes Freet.
Information courtesy of Miller Electric