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Compact Application Tips: When bigger isn’t better

January 07, 2007 |

Contractors quickly realized the value of using smaller sized machinery when working between buildings and incorporated compact excavators into their fleet. They’re such popular pieces of equipment, contractors are using these machines on all types of jobsites. Realizing their adaptability, manufacturers are adding options like long- or extendable-arm configurations and multiple attachments to make the compact excavator useful for even more applications.

Thinking small can cut costs
It’s undeniable the compact excavator’s major attraction is its small footprint – in fact, many models offer a retractable undercarriage and zero-tail or -house swing. But fitting in tight quarters isn’t the machine’s only advantage. Tom Connor, Bobcat compact excavator product specialist, says to consider the cost savings. “Compact excavators are alluring to many contractors because smaller, lighter equipment is easier and less expensive to transport,” Connor says. “It also uses less fuel.” And the tracked undercarriage minimizes damage to finished surfaces, saving you from costly repairs once the job is done, he says.

For some applications, adding a compact excavator to your fleet will decrease the need for subbing out some aspects of the job, Connor says. “Minimizing reliance on a third party makes for more effective scheduling,” he says.

Routine maintenance on compact excavators is also simple, reducing downtime. Mike Ross, national product and training manager, Takeuchi, says several features make servicing the machine fast and easy. “Four of our models, for example, are equipped with a tilt-up operator’s platform to allow quick access to the valves, pumps and engines,” he says. “All of our excavators have a remote slew lubricating system, an automatic fuel bleed system, conveniently located hydraulic pressure test ports and easy access to the battery.”

Connor says Bobcat excavators have engine checkpoints that are both easy to find and reach, as well as a swing-open tailgate and side access hood to allow the operator to easily reach components. “Easily performing routine maintenance ensures operators maintain regular uptime and avoid service breakdowns,” he says.

Don’t let the new features lull your operators into a false sense of security, though – just because maintaining your compact excavator has been made easier, taking appropriate safety precautions is vital.

How small is too small?
The smaller the excavator, the bigger the tradeoff with respect to dig depth, reach, dump height and breakout force. In reality, if you need to dig much deeper than 10 feet, you’ll have to use a larger machine. In response to this limitation, manufacturers have taken a cue from backhoes and started to compensate with extended-arm configuration packages, which can extend maximum depth and reach by about a foot.

When choosing a compact excavator, think about your future business growth along with your present needs, says Bill Anderson, compact excavator product specialist, Volvo. “When an excavator can perform 85 percent or more of the work required, you have chosen the correct size,” Anderson says. “When considering future business growth, you may want to consider going one class size bigger than you presently need.”

All the bells and whistles
The latest models in the compact excavator market focus on enhanced productivity – more power goes hand in hand with improvements in quick-change attachment systems and operator comfort.

Efficiency is key, says Ross. Takeuchi uses variable displacement pressure compensating piston pumps instead of a one-pump load sensing system. The pressure compensating system allows the operator to run several functions simultaneously without a slowdown in speed. “Efficient pumps will provide flow and pressure that give you unmatched breakout force,” he says. “Pressure compensating means the operator can feel and control the pulling power of the machine as he pulls through tough materials.” Ross recommends this over a one-pump load-sensing hydraulic system. “While the load-sensing system does offer good power, the system decreases flow to the slew motor as more than one function is used,” he says. “The operator will find that his ability to slew or rotate the excavator house is slowed. Since the pressure, or power, does not vary, it leaves operators frustrated when excavating tough materials.”

Instead of variable piston pumps which redirect power to different functions, many models, including Ditch Witch and Volvo, offer load sensing systems. These systems allow multiple hydraulic functions to operate simultaneously at full power without compromising performance. “This allows the work group and drive system to be multi-functioned without loss of power,” Anderson says. A load sensing system can also offer a smoother feel in applications such as trenching operations.

“Multifunction hydraulics give operators fast cycle times and impressive digging and breakout forces,” Connor says. “High-efficiency, torque-limiting piston pumps help advanced hydraulics deliver more usable power by continuously responding to loads. More power means more production for the operator.”

Attachment options
The compact excavator’s versatility in using multiple attachments – and the ability to change them out rapidly – makes the machine even more attractive. Anderson says you should not only match the machine to your application, but also match the attachments available for the machine. “Attachments give compact excavators a broader scope of work possibilities,” he says. “Thumbs, augers and hammers allow the machines to be used for more than just digging.”

Ingersoll Rand and Volvo make auxiliary hydraulics standard on its excavators to allow a greater range of attachments. “A standard open-flow return for the auxiliary hydraulic line allows a hammer or similar attachment to be installed without requiring special return lines,” says Jeff Powell, product marketing manager, Ingersoll Rand.

Ease of use and operator comfort has also been addressed. Mike Lumbers, product manager, Ditch Witch, says the company’s newest model enhances comfort and safety. “A wide entrance, a wide seat and lots of floor space maximize comfort,” Lumbers says. “The operator’s station also features a neutral engine start system, which prevents the operator from starting the machine when the hydraulic functions are engaged.”

Consider details enhancing comfort and productivity. For example, Bobcat offers the Hydraulic X-Change mounting system, which means the operator can retract or extend hydraulic pins at the flip of a switch. Volvo’s compact excavators have consoles and armrests suspended with the seat to minimize jolts to the operator. Ingersoll Rand’s newest models allow operators to choose between ISO or SAE control patterns during excavation by pressing a button inside the cab. Look for the features that will prove most useful for your application and operator.

Site savvy
Smaller jobsites not only mean smaller machines, they can also mean a wide variety of hazards. Keeping your eyes open is always important, but when you’re working on small jobsites alertness is crucial. Before you start, check your work area for obstructions, trenches, slopes, dropoffs and overhangs. When operating the machine across a slope, swing to the uphill side to dump the load. Always drop spoil a sufficient distance from the trench to prevent cave ins. Know your soil conditions, and look for rocks, stumps and buried obstructions such as foundations, footings and walls. When you’re working on the edges of an excavation, don’t get too close. The edges could collapse, or the weight of the machine could cause a slide. Don’t dig under the machine – you could cause a cave in.
Source: Association of Equipment Manufacturers

Meticulous maintenance
If you’re working on your compact excavator in an enclosed area, use an exhaust pipe extension to rid the work area of fumes.

Make sure the machine is stationary. Lower the attachment, engage the parking brake, disconnect the battery and remove the ignition key.

Only remove the guards or covers that access the part of the machine you are working on. Wipe away any excess grease and oil. While the guards and covers are open, make sure the machine is not left unattended and keep people away from the machine.

If you are working beneath raised equipment, use rigid, stable supports like jack stands or wood blocks. Never use concrete blocks – they can collapse under even light loads. Check your hoists or jacks to make sure they are in good condition.

Always disconnect the battery before beginning work on the electrical system. Only work on the electrical system if you are completely familiar with the system’s details.

Remember the hydraulic system may hold pressure even after the machine is shut down. Cycle all hydraulic steering and other controls after shutdown, and follow manufacturer’s instructions on relieving pressure. Cooling systems may also be hot.
Source: Association of Equipment Manufacturers

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Compact Application Tips: When bigger isn’t better