According to Caterpillar, good motor grade operators “move the maximum amount of material in the minimum amount of time, run machines safely and know how to cut down on unnecessary wear and tear.”
One of the most important aspects of an operator’s job is keeping the cutting edge sharp. This involves knowing how to operate the grader to protect the blade and, when necessary, to whet its edges.
Why worry about the blade?
It’s obvious that a motor grader depends on its blade, but the blade is far from the most expensive or time-consuming part to replace. So why is it crucial for the operator always to think about the blade?
There are some good reasons. Attempting to penetrate and cut material with a dull or badly worn blade can result in excessive shock, putting pressure on the rest of the motor grader (including the frame and drivetrain). This may damage or significantly shorten the life of components that are much, much more expensive and difficult to replace.
A worn blade also makes a motor grader less efficient. More horsepower is needed to force the blade through each cut, resulting in higher fuel costs, more wear and tear on tyres and lower overall productivity.
It’s down to the operator
Like other aspects of motor grader operation, proper use of the blade comes down to operator know-how and experience. An expert operator can significantly reduce wear and tear on a grader’s cutting edge, helping keep it even and sharp.
To keep the blade of a motor grader sharp, it’s vital to position the moldboard correctly and to use appropriate speed, avoiding jerky movements.
Positioning the blade
When operating a grader, it can be tempting to keep the moldboard pitched forward so you can see the cutting edge. However, this will prematurely blunt the edge, making cutting and trimming more difficult.
Instead, to keep the blade on a motor grader sharp, an experienced operator keeps the top of the blade just slightly forward of the cutting edge, pitching the blade forward only when it’s necessary to make a cut.
The operator should also periodically change blade angles. Keeping the moldboard forward results in wear just along the front of the cutting edge. Periodically tilting it back – for example when carrying, mixing, spreading or combing material – will even out the wear across the edge, helping keep it even and sharp.
Using a motor grader to scarify or rip a surface can also help keep the blade sharp, preventing the cutting edge from becoming rounded along just one side.
When grading curbs, it’s important to switch between leading with the left and right side of the blade. Ideally, aim to use the entire length of the moldboard, preventing uneven wear only to the outer sides of the leading edge.
Slowly does it
In the case of grading, quicker isn’t better. Operating a motor grader slowly and smoothly is the best way to avoid unnecessary wear and tear.
Generally it’s best to keep to a speed below 10 kilometres per hour, and never to exceed about 16 kilometres per hour.
Keeping approach speeds sensible and avoiding jerky motions help minimise stress on the blade and prevent shock loads that can damage other parts of a motor grader. This also prevents unnecessary fuel consumption.
Replace when necessary
It’s worth remembering that even with the most expert of operators, the cutting edge of a motor grader is designed to wear and will have to be replaced eventually. The blade should be regularly inspected. Replace it if there are signs of excessive wear or bending, or if there are missing bolts.
At KH Plant, we specialise in reconditioning Caterpillar motor graders, restoring them to as-new condition. Contact us for more information or a quotation.
