"Compact excavators excel at precision and accuracy," Rabe comments. "But due to their smaller size, they are not efficient large volume material movers. Compact excavators can do the same job as full-size machines, but they may take too much time to get the job done. So contractors should consider moving to a larger excavator when high-efficiency material moving is the primary application objective."
How deep do you need to dig?
Dig depth is likely the most important selection parameter with any size excavator. It defines the work envelope, Wolf points out. Like many manufacturers, Case offers multiple arm length options to meet different reach or dig depth needs.
Avoid the temptation to skimp on dig depth capability. Using the smallest model that can do the job could cause you to sacrifice productivity.
For example, if you need to dig 8-ft. holes, Aldridge advises against trying to get by with an 8.5-ft. dig depth machine. "That size machine will dig your 8-ft. holes. But as far as the speed of the machine and the productivity, it's just not there," he says. "You will want something with more power for more speed and productivity. You would want something more like 12 ft. That will give you the speed and power to dig down and work as fast as you can."
However, if most of your work is utility work that's just 3 to 4 ft. deep, you can get by with a smaller machine. If you do occasionally dig deeper, consider renting a larger unit for those jobs.
Most compacts will also have a dozer blade, which is a benefit for backfilling trenches. "Our three largest compacts have an available power angle blade to help reduce the time required to backfill a trench," notes Caldwell.
What attachments will you use?
Attachments define the hydraulic flow and coupler requirements for the excavator. Consider how much flow/pressure is required with the attachments you're likely to use, especially those with high-flow requirements, such as augers and breakers.
When considering attachments, also take a look at pump sizes/numbers/types, etc. needed to run those attachments, suggests Aldridge. "We have four pumps in our excavators," he says. "That gives you the ability to run multiple functions at once without losing power from one function to another."
Most manufacturers have progressed away from gear pumps to piston pumps, which require less horsepower to run. Granted, they're more expensive, but they're also more efficient and last longer.
"Piston pumps give you the same flow and working capabilities, but with less horsepower," says Aldridge. "That gives you the ability to run a smaller engine, and that leads to lower emissions and lower engine costs."
What weather will you work in?
Canopies and cabs for compact excavators have come a long way. With today's machines, more spacious platforms, pilot proportional joystick controls and standard load-sensing two-speed travel are just a few of the features you will find.
If a considerable amount of the jobs you're doing are in dusty conditions or inclement weather, you might want to consider upgrading to an enclosed cab with climate control options, suggests Wolf.
What are the ground conditions?
The ground conditions you're likely to encounter help determine if rubber or steel tracks are the better choice. Some manufacturers also offer steel track with rubber track pads. While this option is more expensive, it can provide a balance between the durability of steel with the softness of rubber.
"Almost all compacts are sold with rubber tracks. Rubber tracks don't tear up asphalt or concrete," Aldridge notes. "But steel tracks offer more traction and they're more durable for use in severe applications such as demolition. We sell a limited number of steel tracks, mostly in mountainous areas."
What is your work area clearance?
Compact excavators shine in tight and confined spaces. But you will want to evaluate just how tight and/or confined your typical work site is.
"For a new construction site, size is typically not an issue since there are no obstructions," says Rabe. "But with an existing jobsite, which may have trees and restricted access, size is critical."
The application is a key factor in machine sizing, he continues. For example, you may be able to fit a 6-metric-ton unit on the jobsite, but the application may only require a 3.5-metric-ton unit, which in turn may be a more efficient unit for the job.