February 2016, Vol. 71 No. 2
Features
Selecting The Right Compact Excavator
The increasing popularity of compact excavators in recent years has spearheaded a vast selection of models. Today, equipment manufacturers make enough different models that construction contractors can choose one tailor-fitted to their needs. With all of the choices, how do you find the machine that’s right for you?
Ask the right questions
First, there are some important questions construction contractors should ask themselves, says Tom Connor, excavator product specialist for Bobcat Company.
One of the first questions to answer is whether you need a compact excavator? If you frequently rent a compact excavator or subcontract work performed by compact excavators, then you likely can justify adding one to your equipment fleet. “Generally, construction contractors will find more uses than anticipated for the machine once it’s in their possession,” Connor says.
Contractors should also ask whether the desired unit will meet their needs. “A construction contractor should evaluate the anticipated tasks and select a machine that has the capabilities to perform those tasks with room for growth,” Connor says. “It’s also important to assess maximum utilization of the machine. Does the manufacturer offer attachments and does the dealer stock them? Does the machine have an easy-to-use attachment mounting system? Is the machine designed to accommodate a hydraulic clamp?”
Size, power, performance
For most construction contractors, machine size is critically important since many of them install utilities and move materials in confined commercial and residential areas. “A contractor needs to evaluate the anticipated worksite limitations – often width,” Connor says. “In general, midsize to full-size compact excavator models appeal to the construction industry when larger machines are too bulky.”
Should contractors encounter confined areas, some manufacturers offer compact excavator models with retractable undercarriages. Connor says this feature on the Bobcat
M-Series 418 and 324 compact excavators is especially popular among construction contractors with limited access. It allows the operator to retract the undercarriage, pass through a gate or fence, and then expand the undercarriage when actually working.
Knowing contractors don’t want to sacrifice performance for size, equipment manufacturers are packing their smaller excavator models with more power. For example, some of the smaller Bobcat compact excavator models feature bucket breakout forces of 3,620 pound-force and 4,991 pound-force, respectively. For added digging reach or depth in confined areas, contractors can choose compact excavators with long-arm or extendable arm options.
“For example, if lifting 1,000- pound spools will be a frequent, recurring task for the excavator, then one needs to select a machine that will comfortably accomplish this,” Connor says. “If minimum cover is eight feet, for instance, then at an absolute minimum, you should be looking at a machine capable of digging
10 to 12 feet to achieve decent production.”
Tail swing options
When compact excavators first hit the U.S. construction market in the mid-1980s, there was only one kind of tail swing – conventional. But today, there are also excavators with zero tail swing and minimal tail swing, which give operators more unrestricted rotation and provide flexibility when working close to objects or against a wall. The zero tail swing feature virtually eliminates the chance of the excavator’s tail inadvertently contacting surrounding objects. The minimal tail swing feature significantly eliminates the chance of hitting the front corners, and the frame stays within the width of the tracks to avoid damage, Connor says.
Generally, a zero or minimal tail swing compact excavator of a given size will be wider than its conventional-tail-swing counterpart. If a utility contractor anticipates routine work where they must pass narrow property lines, gates or fences, a conventional-tail-swing excavator may be a better fit for his equipment fleet. For instance, Connor says the typical width of a conventional-tail-swing, 3 – 4 metric ton compact excavator will be about 60 inches, whereas zero and minimal tail swing excavators with similar performance will have a width of about 70 inches.
A very popular and practical compact excavator feature is easy-to-use attachment mounting systems. Connor says many manufacturers offer their own type of attachment mounting system for common connections, such as trenching buckets, grading buckets, plate compactors, hydraulic breakers and augers. A user-friendly attachment mounting system encourages the operator to use the right attachment for the task at hand.
“Compact excavator comfort is important to more and more buyers,” Connor says. “This trend drives manufacturers to increase operator space, enhance entering and exiting of the machine and provide features such as an enclosed cab with heat and air conditioning.”
Safety, maintenance
Manufacturers have incorporated several safety and maintenance features in their compact excavators to protect operators. For example, Connor says Bobcat compact excavators have a control console lock system that helps avoid unintentional activation of the machine’s boom, arm, bucket, slew and travel systems. Construction contractors should also check if the manufacturer offers Tip Over Protective Structure/Roll Over Protective Structure (TOPS/ROPS)-rated cabs and/or canopies and retractable seat belts, Connor says.
When comparing compact excavator models, Connor suggests investigating whether routine maintenance items can be easily accessed. He says you should look for a compact excavator that has easy, convenient access to all of the daily checkpoints, such as vital machine fluids and other important maintenance items. Also, check to see if the machine has centralized grease points for the slew bearing, pinion gear and swing boom.
Above all, the best way for you to compare compact excavator models is to operate them under load, because not all compact excavators are created equal, Connor says. You should target demonstration in real-life situations, such as loading trucks or trenching, because some machines’ production and speed increase by as much as 30 percent over others – simply due to the balance between the hydraulic system and engine horsepower.
“Ask the dealer for the ability to demo the machine,” Connor says. “Examine the machine’s versatility, operator comfort, ease of routine maintenance, and of course, performance.”
FOR MORE INFORMATION:
Bobcat,
(866) 823-7898, www.bobcat.com
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