How To Select an Engine-Driven Welder for the Jobs You Do Most | MillerWelds

How To Select an Engine-Driven Welder for the Jobs You Do Most

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The type of work you do and where you do that work are among the key factors in choosing the right engine-driven welder for the job.
Service technicians welding on construction equipment outside using a Miller engine-driven welder

Choosing a Portable Engine-Driven Welder

Engine-driven welders are essential pieces of equipment on most every jobsite, but how do you choose the right one? The jobs you do most often and where you’re doing that work help determine which engine drive will best fit your needs. 

Whether your jobs demand more generator power or high-quality welds, you can find a machine to help you get the work done efficiently. Think about these factors when choosing an engine-driven welder.

What type of welding are you doing and where does the welding take place? 

Whether you’re mostly doing welding repairs or structural field welding, selecting the right machine for your needs is based largely on the welding process being used and the consumables required to do the job. 

Common types of welding processes used with an engine-driven welder include: 

  • Stick Welding: Jobs in the field such as heavy equipment repair, field fabrication and structural fabrication often use stick welding. While 1/8-inch 7018 electrodes are among the most commonly used filler metals used for stick welding, larger sized 7018 rods may be used when thicker material is being welded. 6010 electrodes are also common for stick welding.

  • Self-shielded flux-cored welding: When productivity is more critical in the field, such as for some welds in structural fabrication or field fabrication, self-shielded flux-cored welding is a better choice than stick. Many jobsite welding applications require switching between the flux-cored and stick processes, so it’s helpful to have a machine that allows for quick changeover between the different processes. If the welder must walk to the power source to make these changes, it adds downtime and increases safety risks and the potential for slip, trip and fall injuries. ArcReach® SuitCase® Wire Feeders allow operators to change processes right where they’re working — saving time and improving jobsite safety. The feeders have also been extensively field-proven, delivering advanced wire processes in the field for more efficient welds and optimized reliability in flux-cored welding.  

  • Aluminum Welding: Having the ability to weld different materials in the field, including aluminum, can improve versatility and productivity for any operation or field fabricator. When the job calls for welding aluminum, choose a system with direct connect spool gun capabilities.  

The amperage you need in a machine is very job dependent. For example, if you do a lot of gouging or welding with large-diameter wire, a 300-amp or more machine is likely needed. 

You may also want to look for engine-driven welder options that provide advanced weld control and output. For example, some systems make it easier for welders to precisely dial in advanced weld settings for optimal results. Advanced features and options on some machines in the Miller® engine-driven welder lineup include Dynamic DIG™ technology, which provides a smoother, more consistent arc that can be tailored for stick welding; inductance control for MIG and flux-cored welding; Auto Stop and Auto Crater technologies for TIG welding; and ArcReach technology, which lets operators make parameter adjustments at the weld joint without the need for a control cable for improved arc-on time and jobsite safety. 

What type of fuel do you prefer?

Most engine-driven welders are available in gas, diesel and even LP models. Choosing the right option for your needs depends on several factors, including cost, weight, and space requirements, as well as any fleet fuel compatibility if that is a factor. Gas engines can offer a lower initial machine cost and reduced weight and a smaller size. Diesel engines can use significantly less fuel than gas models while providing longer engine life and they also may be required on some outdoor jobsites. Select the fuel option that best suits your needs and work environment. 

How much power does your operation need?


Engine drives offer power generation capabilities ranging from 5,000 to 20,000 watts. Choosing the right one depends on the type of tools you run and if you need to simultaneously weld while running other tools.

When thinking about your power generation needs, it’s important to know the wattage needed to run common tools. Grinders typically require 1,800 watts, cut-off saws may require up to 2,400 watts, air compressors often start at wattage requirements of 8,200 and impact wrenches may consume 500 to 1,200 watts.

How often are you cutting or gouging?

Many repair jobs in the field require cutting out damaged metal or an old weld. An engine drive gives you the option of using a plasma cutter or carbon arc gouging for this work. 

Plasma cutters offer lightweight portability and can cut steel with 10,000 watts of power from an engine drive. Carbon arc gouging is available on most engine drives; machines that offer at least 300 amps of power at a high-duty cycle work best for gouging. If you need to remove a lot of metal, look for an engine drive with a peak output of at least 500 amps. This lets you run 3/8-inch diameter carbons, so you’ll get the job done faster.

Often, work on jobsites also requires the use of different air tools, making compressed air an important function of your engine-driven welder. Miller offers engine-driven welders with built-in air compressors; these machines are denoted with the Air Pak™ label in the name. Be sure to choose a machine that provides the necessary cubic feet per minute (cfm) and pressure required for the tools you will run most often. 

Is multi-operator use important?

On many jobsites, two operators must work off of the same machine. Look for a machine where the welding circuit and power circuit are independent of each other, so it doesn’t cut down on the amount of power being delivered when one operator is welding, and one operator is using the generator power for a plug-in tool. As a result, the system ensures there is no interaction between the welding arc and jobsite tools, so weld quality increases and jobsite tools can run without interruption. Machines with this design include all Bobcat™, Trailblazer® and Big Blue® engine-driven welders. 

Some machines also provide the ability for two operators to weld at the same time. The Big Blue® 800 Duo Pro and the Big Blue 800 Duo Air Pak can be used in dual operator mode, with each operator having access to 400 amps of welding power. This allows for the use of stick electrodes up to 1/4-inch thick as well as self-shielded flux-cored wires up to 5/64-inch thick and gouging electrodes up to 5/16-inch thick. Dual operator machines like these are beneficial for LNG tank manufacturing and large infrastructure jobs, since the operation can get multiple arcs from one piece of equipment, taking up less room on the jobsite. 

Is there a frequent need for battery charge/crank assist?

If you often need to charge a battery (12 or 24 volt) or use crank assist to start a machine that doesn’t have any battery power, such as in work truck or MRO applications, look for a machine that has the battery charge/crank assist option available. These capabilities are common requirements for work truck or heavy equipment repair applications that use engine-driven welders. 

Is reducing fuel cost important?

If fuel costs are a primary concern when choosing an engine-driven welder, look for technologies that help save fuel. Several Miller-exclusive technologies on engine-driven welders work in conjunction to decrease fuel usage and lower operating costs. 

Auto-Speed™ Technology and Excel™ Power found on several Miller machines, including Trailblazer® engine-driven welders, are technologies that help increase fuel efficiency and improve machine performance. A machine with Auto-Speed technology responds to the weld requirements by automatically adjusting engine speed to one of several rpm levels, rather than operating at 3,600 maximum rpm under any load like other machines on the market. Operating at the engine speed required for the job keeps the engine from working harder than necessary, saving fuel and money. In addition, a machine equipped with Excel power delivers a full 2,400 watts of auxiliary power at all speeds, even idle. This delivers cost savings since jobsite tools like grinders can be operated at speeds that save fuel. 

Another way to improve fuel efficiency and optimize profitability is to choose an engine-driven welder with electronic fuel injection (EFI). This technology provides faster, more-reliable starts in any weather and delivers up to 42% greater fuel efficiency. 

Do you need a machine that provides space and weight savings?

The size and weight restrictions of your truck or space limitations on the jobsite can also help determine the type of engine-driven welder you choose. Smaller units have a smaller footprint and can weigh as little as 242 pounds while still offering 6,500 watts or more of generator power. Larger units can combine air compressor capabilities with the welder and generator. This saves space but keep in mind that it does add weight. 

The new Bobcat™ 265 and Bobcat™ 230 , for example, are more than 100 pounds lighter and 13% smaller than previous models while still providing dependable welding and auxiliary power for a wide variety of applications.

Know your weight, size and mounting restrictions so you can make an educated choice that fits your needs.  

Is jobsite noise a consideration?

Working in some locations, such as near a school or residential neighborhood, may require attention to noise levels on the jobsite. Many of the technologies mentioned above, including Auto-Speed technology, Excel power and Remote Start/Stop capabilities, help reduce noise on the jobsite because the machine can run at lower rpms for certain jobs or be easily turned off when it’s not in use. 

The right engine-driven welder saves time and money

Choosing the right engine-driven welder for your needs can help improve productivity and save money. Whether you are looking for advanced welding capabilities, fuel-saving technologies or a machine that is easy to use and maintain, there are options available for a wide range of applications in the Miller engine-driven welder lineup. The right machine can help your operation complete work faster, while still improving quality and safety.

Check out the engine-driven welder offerings from Miller and find the one that best meets your needs.