Despite their diminutive size, compact excavators are often subjected to harsh applications. Yet, when properly selected and fitted, these machines can thrive in the most demanding environments.
Bobcat Co. designs it excavators with the assumption they will be used in tough applications. "We assume that almost any excavator we build is going to end up with a breaker on it just because it is such a commonly owned or rented attachment," says Tom Connor, excavator product specialist. "From the basic plumbing, work group structure, pin sizing, etc., we basically assume there is a high probability the excavator will spend 10% to 50% of its life in demolition applications. Your main focus may be excavation. But if you run into a situation where you have to bust rock, we don't want you to have to rent another machine or beef up your machine to allow that."
The design of key components will give you an idea of the unit's overall durability in such applications. "For example, IHI compact excavators come standard with a one-piece boom, which is more durable in a demolition application," notes Kendall Aldridge, IHI/Compact Excavator Sales.
Wacker Neuson incorporates structural steel and high-quality components in its compact excavator line. "Our torsion-resistant X-shaped chassis frame, the solid welded structures and the steel castings used in high-stress areas ensure that our machines are robust," says Jay Baudhuin, compact equipment manager. "Also, our pins and bushings are purposely designed to be oversized."
High-stressed bearings are supported by replaceable hardened steel bushings with special machined grease grooves. "These bearings, pins and bushings mean the machines can withstand severe-duty applications, there will be lower maintenance cost and higher resale value," says Baudhuin.
Select tracks for conditions
One of the most important considerations with compact excavators is track selection. Three types are available: rubber, steel and hybrid, which is steel with rubber pads.
"Rubber tracks are the most popular choice because they do less damage to grass, asphalt or concrete pavement, or other sensitive surfaces on the way into or on the jobsite," says Bill Gearhart, marketing and product manager, Yanmar Construction Equipment. "If the jobsite or jobsite entrance is covered with broken concrete or jagged rocks, steel tracks would be preferable, as these conditions can prematurely wear or damage rubber tracks."
Steel tracks are suggested for demolition applications, where sharp metal parts could slice rubber track and expose the embedded steel cables. "The advantage of steel tracks in these harsh conditions is that they will wear better than a rubber track," says Baudhuin. "The disadvantage is if used on sensitive, soft ground, such as landscaping or asphalt, the tracks can damage the ground. Also, steel tracks will have more of a tendency to slip on some surfaces (like a wet trailer ramp) than a rubber track."
You really need to evaluate how you intend to use the machine. "Extreme demolition applications where debris becomes a factor in tearing up tracks is an excellent time to look at steel tracks," says Aldridge. "The advantage to steel track is the longevity factor. The disadvantage is that the contractor is limited where the unit can be used."
Weight can become an issue if you are close to the 10,000-lb. commercial license requirement with the truck, trailer and equipment. "Typically, a steel track will up the operating weight of the machine 1% to 5%," says Connor. Noise can be another concern. "Some people object because they are noisy compared to a rubber track."
And while they last longer, a steel track is typically more expensive to get into than rubber track. "That kind of flip-flops when you get into the 16,000- to 20,000-lb. machines," notes Connor. "Rubber tracks are kind of a new thing for that size."