Like any excavator, compact models in the 2.5- to <3-metric-ton size class excel at digging holes. But they're also highly capable tool carriers that can deftly handle a wide array of hydraulically powered attachments from augers, plate compactors, breakers or thumbs.
Breakout forces on these machines range from 3,600 to almost 5,000 pounds, meaning they can dig aggressively and lift significant payloads on urban jobsites. These traits, combined with their compact, highly maneuverable profile and easy transportation characteristics make this class of compact excavators attractive for utility, demolition and residential construction contractors who need a flexible and maneuverable machine that can work in restricted surroundings.
Pick and choose excavator options to best match applications
Typical applications for compact excavators in this class include grading for footings and digging foundations. For that reason, Lance Mathern, product manager, Bobcat, recommends basing machine size on dig depths and access to and around the jobsite. “They’re outstanding machines for remodeling contractors,” he notes. “If you’re putting additions on houses or doing hardscape work, you can come into the yard, break up a patio and dig trenches for a foundation for the addition.” Other jobs include compacting trenches, tearing out old concrete or sod and going inside a building to do light demolition work with a small hammer.
At the same time, Dan Burch, product manager, Caterpillar, says you should consider which attachments you’ll require on current and future jobs when spec’ing a compact excavator in this class. Other considerations he points to are the various materials you expect the machine to work in (rock, clay, sand, concrete) and if you plan to do any truck loading with the machine.
Although compact excavators in this class are not mass production machines, they can be effective in limited truck-loading applications. If this is a possibility for you, Burch says, pay attention to the height requirements you’re dealing with and make sure they’re within the excavator’s operational envelope. And, Burch says, don’t forget the physical dimensions of the machine itself. One of the principle reasons for the explosion in the compact hydraulic excavator market is due to their size and weight. So consider what weight can be towed with your existing trucks and trailers, and make sure the machine is a good match for them.”
It’s also important to decide if you’ll be using a compact excavator as a primary or support machine on your jobsites. They excel in either role, supporting backhoe loaders, trenchers, directional drills and similar pieces of equipment, or as the main piece of equipment excavating and running attachments.
“Compact excavators are most effective when used as part of a system approach to equipment deployment on utility jobsites,” observes Mike Lumbers, senior product manager, compact utility equipment, Ditch Witch. “Using them to support trenchers and directional drill rigs gives you an added degree of flexibility on a jobsite and allows each machine type to work in its niche specialty more effectively.”
Remember you can pick and choose machine options to better match your intended applications. Many OEMs, including Caterpillar, offer a choice of standard and long sticks for compact excavators. In a trenching application, Burch notes, a long stick configuration can reduce the amount of machine repositioning required when excavating and reduce the time needed to complete the job. But, he cautions, if the excavator is digging in extremely hard, compacted material, a standard stick may be a better choice because of the inherently higher breakout forces offered by shorter stick geometry.
Consider spec’ing a machine with zero tail swing, suggests Lowell Stout, product manager, Terex Compact Equipment. “A zero-tail-swing machine swings within the width of its tracks,” he notes, “and can work in extremely tight surroundings.”
But there are trade-offs. Stout says zero-tail-swing models often have a wider track gauge than conventional models, which can cut down on their ability to move through restricted access areas. Also, zero-tail-swing models have heavier counterweights to offset the short overhand on the rear of the machine, and that could be an issue when transporting the machine.
Some compact excavators are equipped with variable-gauge track widths, says Randy Vargason, marketing manager, Mustang. This feature is a definite advantage in getting into tight work conditions.
Consider different stick and boom options to optimize trenching applications.
Speed without precision saps productivity
Regardless of whether you intend to use the machine in a primary or support role, a certain amount of productivity is expected. Most OEMs will tell you tracking productivity with compact construction equipment is tricky, since they are not designed to be high-volume earthmovers. For most contractors, simply finishing a job in as short a period of time as possible is a sufficient production marker.
But what can you do if you suspect your compact excavator’s productivity isn’t quite up to snuff? Odds are you’re a small contractor and don’t have any previous foot-per-minute production figures to use as a benchmark. There are still operational issues you can watch for and correct to improve machine performance, according to Burch.
First off, ask yourself if you selected the right machine for the job. In extreme cases, even though the compact excavator you’ve got on the jobsite might be working at full capacity, your production may be lacking. If that’s the case, then you have to consider the possibility a larger machine would be a better match for the job – provided you can maneuver it and fit it into the job’s surroundings.
If you think you’re all right in terms of machine size, check your boom and stick geometry to ensure they’re appropriate for the types of soil and applications you’re operating in. “If you’re using a thumb, are you digging with it on the front end?” Burch asks. “If so, the excavator’s lifting capacity will be reduced and productivity will be affected.”
What about your operator? If the operator isn’t comfortable with the controls, that can definitely cause problems in the trench. If you suspect that’s the case, remember most compact excavators in this class are equipped with pattern changers that can swap from SAE- to backhoe-style controls.
If you’re spending too much time changing attachments, Mathern suggests looking into getting a quick coupler to facilitate the process. “Make sure you’re taking advantage of the machine’s offset boom feature too,” he adds. “Some operators who put teeth on larger machines fail to take advantage of this option and waste time repositioning a compact excavator when they don’t have to.”
Another mistake Mathern cautions against is being obsessed with speed while operating. Instead, he suggests concentrating on precision control when first learning to operate a compact excavator. “Speed will come naturally once you’ve mastered the art of precision with the machine,” he says. “But speed without precision costs you productivity. You end up overshooting a trench or reaching out beyond where you need to go loading a truck, for example. You end up doing a lot of backtracking with the controls and that wastes time.”
Attentive operators increase rubber track life
Mike Ross, product manager, Takeuchi, will tell you pins, bushings and buckets are the biggest wear items on a compact excavator. But many contractors worry about the durability and life of the rubber tracks on their machines. Thrown, cut and torn tracks, or tracks that wear out faster than you deem appropriate, can leave a bad taste in your mouth.
Still, rubber tracks are the norm for compact excavators in this class – less than 1 percent of all models sold in the 2.5- to <3-metric-ton class are fitted with steel tracks, and those machines are destined for use in severe applications. Ross says the excavator's operator has the most dramatic impact on track life. "I've seen tracks go bad in 1,000 hours, and I've seen them last 2,500 hours," he says. "Unlike a compact track loader, if you're digging with an excavator, you're probably only actually using its tracks about an hour out of a full day.
So focusing on track wear is something an operator can easily be trained to do."
Checking track tension is always important, but particularly when a machine or its tracks are new. New tracks have some inherent stretch in them and can be easily thrown if proper tension is not maintained, according to Mathern. "I always recommend checking tracks every day for a week when they're new," he says.
In addition to track stretching, new machines can have excess air trapped in the track tensioner cylinder. This air can bleed out, letting the track get slack and increasing its chance of getting thrown.
To check tracks, Mathern says you should step lightly on them and see if they bear that weight without giving more than an inch or two. "If the track is loose, impress on your operators that three or four minutes with a grease gun in the morning can save a lot of time and headaches later in the day," he adds. "In addition to the field checks, it's a good idea to periodically elevate each side of the machine separately and formally evaluate the slack in the track. That's the right way to enhance the life of the track and the undercarriage components."
Once the machine is on the job and working, Ross says the operator needs to be careful and attentive whenever the machine is moving. "Go perpendicular over curbs," he says. "Don't move any faster than is absolutely necessary and be careful when working around rocks, broken concrete and rebar. Remember the more careful you are the more track life you'll get."