Grade School
The New-school Machine for the Old-school Operator
By Jason Morgan
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| Much more important than blade down pressure is the pitch angle of the blade. The right angle allows the dirt to flow more smoothly. But there’s no magic number for the angle; it’s going to depend on the job conditions. |
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Even in elementary school, future contractors saw that the big picture was filled with small details. The daunting start of shoebox dioramas, Styrofoam solar systems and exploding volcanoes led to an arduous end of fine finishing work that gave that feeling of accomplishment. The beginning of every new project is exciting and a little nerve-racking; as adults on the jobsite, the contractors get that same rush after winning a bid. While our parents aren’t around to get us started and help us finish, the motor grader sees us through the beginning and the end of the project.
When prepping the jobsite, motor graders are used for rough road cutting to allow excavators to dig to the utilities. For many utility jobs, there is a need for the motor grader to level and even dig and install operations. After the job, motor graders take care of the fine finishing work — leveling and grading the road for re-pavement.
Motor graders are categorized by horsepower; typically, utility-spec’d motor graders fall within the 140- to 200-hp range. But the size of the motor grader is generally dictated by the jobsite conditions and requirements.
“If there is going to be a significant amount of material to be handled then the size would increase,” says Phil Newberry, Market Development Engineer for Motor Graders, Caterpillar Inc. “The size of machine depends partly on productivity requirements, meaning a smaller unit can do the work of a larger unit but it will require additional time.”
Within any motor grader, there are a bevy of new-age features. From controls and attachments to blade materials and grading system add-ons, a new technological age has dawned on the motor grader market.
School’s in Session
Working from the inside out, the first thing an operator may take notice of is the control scheme. There are two schools of thought in motor grader controls — lever and steering wheel and pilot-controlled joysticks. Multi-lever controls aim to prevent function cross talk in precise applications and limit wrist rotation in operation. Joystick controls aim to simplify motor grader controls by placing all of the machine’s controls into two joysticks.
Popularized by Caterpillar’s M-Series motor graders, the joystick controls work in tandem. The left joystick primarily controls the machine direction and speed. To steer the machine you lean the joystick left or right and can twist the joystick to either side for articulation. The left moldboard lift cylinder is also controlled by the push and pull of the joystick to lower and raise the blade, respectively.
The right joystick primarily controls the drawbar, circle and moldboard functions. Like the left moldboard lift cylinder, the right moldboard cylinder is controlled by pushing and pulling the right joystick. A thumb switch (left and right) also controls the drawbar center shift. Finally, triggers control the electronic throttle control and differential lock and unlock.
On the other hand, the lever and steering wheel control operate in a very easy and logical manner. The steering wheel controls the machine direction and a series of 10 separate levers, within easy reach of the operator, control the moldboard, drawbar, articulation, front attachment and wheel lean. There are conflicting opinions on motor grader controls within the industry.
While joystick controls have revolutionized the operations of excavators and loaders, operators of motor graders tend to be detailed-focused individuals. Manufacturers such as Komatsu and John Deere are not convinced that joystick control is the answer to lessening the motor grader control learning curve.
“In the industry it seems like joysticks are the end-all, be-all of control, but in a survey Komatsu did with customers, many still prefer the conventional controls for easy operation,” says Steve Moore, motor grader Product Manager for Komatsu. “A motor grader is a finishing tool; the type of people who run them are more concerned about what kind of controls make that machine operate vs. a wheel loader or excavator. I still think the jury’s out on what kind of controls you need on a motor grader.”
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| Once populating the jobsite, grading stakes are becoming an icon of the past with the popularity of GPS and laser grading systems that automatically alert the operator of the grade. |
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“Lever controls retain the control pattern that has been the industry standard for 30 years,” says Jeff Rowan, John Deere Product Marketing Manager. “The way to really simplify operations is to concentrate on how the operator and the controls work together and to get that exactly right. One example of this is the high level of integration with productivity-enhancing electronic grade control systems like Trimble and Topcon. Manufacturers like Deere offer plug and play integration with both major grade control providers to accommodate any customers’ preference.”
Next to control preference is the machine’s visibility. Many manufacturers — like Case, Komatsu, John Deere, Caterpillar and Volvo — have made great strides in providing the best visibility to the blade and rear of the machine for precision operation and safety.
“The key with motor graders is operator experience,” says Rowan.
“A Deere grader, for example, has numerous features in the cab to help the experienced operator to be as productive and accurate as possible, but it comes down developing expertise.”
Driver’s Ed
The nerves kick in when you put the machine in gear.
Although mailboxes and curbs were the obstacles during driver’s education, the pressure on motor grader operators comes from being able to hit their grades while watching for manholes and the like. The drive functions of today’s motor grader are as varied as the manufacturers. The most common shared drive transmission is all-wheel drive. All-wheel drive provides added tractive effort in poor traction conditions, like mud, and improved drive control for fine grading.
Among the transmission offers from the multitude of manufacturers, Komatsu offers dual-transmission that switches the machine into an automatic-style transmission when engaged.
“For everyone who is running a clutch, when they start inching for fine work, they are going to have to clutch the machine,” says Moore. “The dual-transmission is like your car. When you come up to a stop light, you take your foot off the accelerator and put it on the brake. It has a torque converter, so 1) you don’t need to use a clutching pedal, 2) it’s very smooth and 3) it’s very easy to use. You can imagine a motor grader operator just using his accelerator to inch around manhole covers and curbing vs. trying to run the throttle and clutch using two pedals.”
Volvo offers an 11/6 transmission that has 11 forward and six reverse gears. This provides the operator with greater speed control and efficiency for fine grading work. Caterpillar offers electronically-controlled shifting, which optimizes inching modulation and smoothes shifting between all gears and directional changes.
These different transmission offerings add to the productivity of the machine but it can also lead to fuel efficiency, but that’s not the only factor.
“In some states there are shutdown policies,” says Moore. “There are aftermarket automatic shutdown devices. Like the trucks in California that are required to shut down if the machine idles more than two to three minutes; it’s going to take it down from an high idle to a low idle or shut the machine off. With this equipment, there are so many variables that you might not want to shut down the machine, but shutdown policy is an avenue to look at.
“The other technology is the satellite-based fleet management systems. It tells you how much fuel you have and then you can determine how much fuel you’re using by hour or by day and how much idle time the piece of equipment is doing. So as a manager, you can take this data and say, ‘this machine was idling 66 percent the other day.’ He or she can make a management judgment to shut the machines down and save fuel.”
Making the Grade
Regardless of the new control schemes and transmissions, it all comes down to how your operator cuts the grade. While grading stakes sprouted up from the ground like pylons of productivity in the past, today’s jobsite is going stakeless thanks to laser and GPS grading systems. Offered by many manufacturers who partner with grading-system experts Trimble and Topcon, the popularity of grading systems in motor graders is taking off, depending on the job conditions of course.
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| When prepping the jobsite, motor graders are used for rough road cutting to allow excavators to dig to the utilities. After the job, motor graders take care of the fine finishing work —leveling and grading the road for re-pavement . |
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“Laser and GPS systems are on an estimated 70 percent of the graders on major site prep and new road construction projects,” says Mitch Blake, Case Brand Marketing Manager. “For county road work maintenance, this percentage would be much lower.”
Similarly, Komatsu is expecting to see a near 20 percent increase in grading systems within the next five years. “These systems are gaining acceptance in the market very rapidly,” states Moore. “
All highway work is going to use a [grading system]. The only stakes you’re going to see on a highway job are the ones to lay down the concrete or asphalt. Komatsu is expecting to see motor graders moving from 10 percent usage of the GPS grading systems into the 30 percent realm. It’s in dozers, it’s in excavators, so it will take off. That’s where the future is going.”
These systems can also save the contractor material cost. If an experienced grader operator with electronic grade control can do the job in a more controlled manner, grading to 1/8 in., instead of 1/4 in., for example, the contractor can save a lot just in dirt, over the length of a large project, says Rowan.
Aside from the productivity of new-fangled technology, keeping your machines maintained always gives a boost to machine efficiency.
“Fuel, engine oil and hydraulic levels, as well as air filters should be monitored daily,” says Blake. “Belts, hoses and wear surfaces should be checked monthly. Analysis of the machine’s lubricants should be done every 6 to 12 months. Lubrication of the unit should be followed per the recommendation of the manufacturer.”
When you invest $270,000 to $300,00 for a utility-spec’d motor grader, keeping your motor grader primed and productive keeps your operational costs down and profits up. Just as motor graders take on finer work toward the end of a job, the management of motor graders is in the details. Machine up-time, idle time, productivity and efficiency all come together to keep your crews motoring.
Jason Morgan is Associate Editor of Utility Contractor.
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