Construction Equipment Guide
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800-523-2200
Mon July 20, 2009 - National Edition
Using a grader attachment on a Bobcat loader is an alternative to dozers and an efficient method of spreading and grading material, especially on job sites larger equipment can’t access. Bobcat now offers two additional grader options for larger and more powerful loaders. New features include hydraulic side-shift for easier grading in tight areas or next to obstacles and an end-wing kit to use the grader like a box blade.
Grader attachments are typically used to prepare base material for roads, parking lots, buildings, sports fields and lawns. The new 96- and 108-in. (244 and 274 cm) graders are approved for use on Bobcat S300 and S330 skid steer loaders; the Bobcat A300 all-wheel steer loader; and the T250, T300 and T320 compact track loaders.
The combination of a heavy-duty grader on an approved loader will move as much material as a small, dedicated dozer. When used with the Bobcat laser-control system, grader attachments on loaders will grade material to within plus or minus 0.25 in. (.6 cm) of the desired grade, according to the manufacturer.
Bobcat graders have blades that move six different ways to grade any surface. A new feature available on heavy-duty graders is hydraulic side shift, which moves the blade as much as 13 in. (33 cm) to the left or right, making it easier to grade next to buildings, poles and other obstacles. This feature eliminates hand labor and excessive movement of the loader when grading. When the grader approaches an obstacle, such as a pole, the blade can be moved out of the way and then moved back in place once the pole has been passed.
A feature normally found on dedicated dozers also is now available on Bobcat heavy-duty graders. A proportional hydraulic valve provides three speeds at which the moldboard is raised or lowered so operation is more closely matched to the speed of the loader. The longer the operator presses the button that controls the valve, the faster the moldboard moves. The operator can make small adjustments when performing fine grading or move the moldboard more quickly when making faster passes.
The proportional hydraulic valve provides smoother operation and quicker reaction of the grader when used with a laser-control system. With the laser system, the farther the blade is from grade, the more quickly it will move to grade. A high-speed moldboard raise-and-lower function is available on loaders with selectable joystick controls, to allow the operator to override the laser system and make quick adjustments as necessary.
The front bolster on the graders oscillates 12 degrees to the right or left to minimize the effect of uneven ground and how much and how quickly the blade needs to respond while grading. The tires on the bolster provide flotation to keep the grader moving smoothly over the work area, according to the manufacturer.
A dirt shield has been mounted over the moldboard to keep material pushing forward instead of coming over the top of the grader. The cutting edge of the moldboard is reversible, and when the edge wears out, it can be flipped over to provide a fresh cutting blade.
A bolt-on end wing kit is available to turn the grader into a box blade. This kit gives the grader two different functions, eliminating the need for an additional attachment. Using the grader with the box blade end wings enables the operator to carry more material, especially sand and gravel, when doing fine grading.
Bobcat recently released new laser receivers for use with grader and box blade attachments. The receivers combine new features that improve grading accuracy and speed while making it easier to make adjustments to the grade. These improvements include in-cab grade control, allowing the operator to adjust the grade from the cab instead of getting out of the machine to raise and lower the transmitter. This feature requires Bobcat selectable joystick controls and permits operators to change the blade position up to 2 in. (5 cm) in either direction to quickly alter the grade.
Another improvement to the new laser receivers is a longer photo cell, making it possible for the attachment to travel farther up or down without losing the signal from the transmitter. This feature enables the operator to stay in the machine to adjust the transmitter and decreases the number of passes it takes for the attachment to complete the grade.
For more information, visit www.bobcat.com.