Know the Basics: Compact Excavator 101

Summary

Mini excavators, also known as compact excavators, are classified as earthmoving machines with an operating weight of 10 metric tons or less. They emerged in North America in the mid-1980s and have grown tremendously in popularity. Their advanced hydraulic systems can outperform larger tractor loader backhoes, and they offer greater flexibility to dig adjacent to objects, place spoil or load a truck. Mini excavators are versatile machines built for a simple purpose – fast, efficient trenching and excavating. It is common to see a compact excavator operated in conjunction with a skid-steer or compact track loader, because the machines complement each other and can get work done faster than larger dedicated earthmoving equipment.

Mini Excavator Main Components

1. House – Attached to the undercarriage with a swing bearing, the house contains your operator’s cab, engine, hydraulic pump and distribution components. The house and the workgroup rotate or “slew” 360 degrees to provide exceptional agility when working in confined areas where larger machines can’t fit. 

2. Undercarriage – The undercarriage includes standard rubber excavator tracks surrounding drive sprockets, rollers and idlers which propel the machine. The most common type of undercarriage for smaller mini excavators is the retractable undercarriage. This H-shaped undercarriage can be retracted to temporarily reduce overall machine width, which is valuable for traveling through small openings or working in tight areas. It should be expanded before doing any work. A fixed excavator undercarriage is typically a little wider than the house structure. 

3. Workgroup – The boom, arm and any attachment you add to the machine are all included in the workgroup. Compact excavators are unique in that their workgroup is connected to the front of the house with a “swing frame.” The swing frame can be hydraulically pivoted left or right so you can do offset digging parallel to the excavator tracks. 

4. Backfill blade – Hydraulically activated and controlled from inside the excavator cab, the backfill blade is connected to the undercarriage and used for grading, leveling, backfilling and dozing. It can also be used as a stabilizer for the machine depending on its position. An angle blade option is ideal if you need to backfill and grade quickly. This option lets you angle the excavator’s backfill blade 25 degrees left or right to direct soil from one side to the other.