Posted on: 18 Jan 2017
Topic: General News
A small machine that can rival the biggest in the industry.
A relatively new entrant in the construction industry, mini excavators have become an indispensable piece of machinery in the contemporary urban landscape. Versatility, size, ease of operation and the convenience of transporting them have made them the earthmoving industry's jack of all trades.
The mini excavator is used by contractors from a wide variety of backgrounds, for an even wider range of jobs, including utility trenching, tree harvesting, tree transport and planting, repairing digs, small scale excavations, grave digging, light demolition, home repair, renovation, and roadside applications.
The mini excavator's ability to work in tight and confined spaces, which are proliferating every day in every city in Australia, combined with their power and maneuverability simply mean that they can go to worksites that bigger machines couldn't possibly access.
Mini excavators are classified as machines having an operating weight of 4,535kg and under. Most mini excavators, also known as compact excavators, have three assemblies comprising a house, undercarriage, and work group. The machine movement and function are controlled through the transfer of hydraulic fluid.
THE GROWTH OF MINIS
Like their larger siblings, the mini excavator is made up of a tracked or wheeled undercarriage or chassis, a cab, and a boom extension with a bucket attachment. Most new mini excavators come with a retractable undercarriage, meaning that the tracks can be expanded and detracted to less than 0.91 m wide or larger enabling the machine to squeeze through tight spaces.
One point worth mentioning here is that the undercarriage can be the most maintenance intensive part of the machine. Mini excavators utilize hydraulic piston pump technology. This technology allows machines to be built with a smaller engine, as piston pumps require 20 per cent less horsepower. The latest hydraulic pump systems are a combination of piston and gear pumps in which different pumps carry out different functions. For example, two pumps typically manage the operation of the boom arm and bucket, and a third pump manages the swinging of the cab.
The first mini excavator, YNB300, was introduced by Yanmar into the Japanese market, in 1968. Takeuchi had their first mini excavator two years later. Soon these machines gained wide currency in Japan and Europe. With the entry of Bobcat into this space, mini excavators gained popularity, through Bobcat's products and promotions, in North America, and then Australia. Bobcat started referring to them as compact excavators.
In the 1990s these machines were spotted for their business value by rental businesses. The rental fleets gave the end-users a risk-tree opportunity to test the new excavators in worksites. From then on, the adoption of mini excavators has progressed impressively, with sales increasing by over 900 per cent from the 1990s to the 2000s. The list of manufacturers too increased considerably from just three players to possibly over 30 players in the current market.
WHAT TO LOOK FOR
While the variety is certainly good news, it also means that users have to understand a machine well before they decide to use it for a particular job. A machine's weight, dig depth, bucket size and function are important considerations when buying or renting. It is important not to get carried away by horsepower. Sometimes a larger mini excavator would be better than a smaller one.
When choosing a machine, it is important to ensure the equipment will meet most of the needs of a particular job. Having said that, the variety in the market means that it's hard to get a one-size-fits-all piece of equipment; rather the "best fit" should be what buyers look out for. Features like air conditioning and cabin comfort can be good; however, some contractors prefer their users to be connected to the outside and to have to step out every now and again to help with other jobs in a site. Last, but not least, training from the manufacturer is vital in enabling a business to get the most out of a machine and avoid downtime from damage or accidents. Below are some of the reason why weight, bucket size and tail swing are important factors.
•WEIGHT: A mini excavator's weight is the key to its versatility. Its light weight also makes it suitable for working on soft or sensitive terrain. Users can be assured that a mini excavator will leave a smaller footprint in any worksite. Lighter machines are better designed for traversing soft or wet ground with pipes and cables not far from the surface. As mentioned earlier, their size also makes them easy to transport in a truck or by trailer.
•BUCKET SIZE: Make sure the bucket size is suited to the job. A smaller bucket,for example, is ideal for digging near utility lines, and a bigger bucket will be perfectfor wet or muddy terrain. The standardrange of most bucket sizes is from 12 to24 inches.
•TAIL SWING: Two other notable features of mini excavators is zero tail swing and independent boom swing. Most manufacturers are now building mini excavators with zero tail swing or zero swing radius. Conventional tail swing is the ability of the machine to rotate at 360°. On the contrary, zero tail swing allows the machine to rotate to the full 360° without the cab overlapping the width of the tracks. Tail swing should be an important consideration before pairing a job with a machine, especially in tight residential or urban areas.
Offset booms, also known as articulated booms or swing booms, are becoming a standard feature on several models. The offset boom or independent boom swing enables the machine to dig within close proximity to walls, foundations, or other structures without having to change angles or be realigned. This provides the machine arm with the ability to dig parallel to the tracks. Machines that permit a number of attachments can save time and money.
A number of machines are manufactured with backfill blades giving the machine dual functional capability to not only dig up dirt but to push dirt back into the hole after being dug up or for basic levelling. Some of the more popular mini excavator attachments are grapple, auger, hammer and thumb, rippers, breakers, clamps, plate compactors, trenchers, and grading and trenching buckets.
The mini excavator's size can be deceptive: a few decades ago heavy equipment operators considered these machines to be toys. Today, their ability to punch well above their weight has earned them the respect of the entire industry, not just for their impressive capability, but also for their small footprint and cost efficiency.
Article featured in Earthmoving Equipment Magazine, December/January 2017 Edition