With articulation, graders are significantly easier to manoevre and more versatile.
What is frame articulation?
Articulation refers to a a flexible joint in the machine’s frame. On a grader, this is usually located near the cab, enabling the front part of the grader to pivot relative to the rear.
The joint acts somewhat like an “elbow”. It shortens the turning radius of the machine and makes it easier to manoevre, allowing sharp turns and improving control in confined spaces.
Caterpillar’s G series
In 1973, Caterpillar revamped its line of machines, introducing the G Series of articulated motor graders. These proved so popular that their design was changed little over the next 20 years.
Today, it’s still true that articulated frame graders are more versatile and accurate than rigid-frame graders, reducing the need for additional equipment on site.
Using an articulated grader: key operating tips
Modern, articulating graders essentially have a pivot point or hinge between the front and rear axles. Using articulation gives your machine improved agility and versatility.
Learning how to use your grader’s articulation effectively will make your grading more efficient and more accurate.
Using articulation when steering shortens the machine’s turning radius which is using when grading in tight spaces. Articulation also allows the operator to:
- Counter side draft from large windrows and blade loads
- Change moldboard cutting width
- Reduce blade loads without using your circle
- Steer the leading end when reversing.
For output in maintenance procedures, there are three modes available:
Straight
Only front steering is used. For most finishing, ripping and scarifying, long-pass blading, light to medium windrows, blading shoulders and dry-ditch cleaning.
Articulated
Uses front and frame steering. As it gives the shortest turn radius, it’s good for close work, like in corners and cul-de-sacs.
For constructing V ditches, spreading materials or operating in small areas, for short turns, V-ditch construction, spreading material and cutting high banks.
If you want to change the cutting width of the moldboard and lessen blade loads without using the circle, this is the mode to use.
Crab
Here, the front wheels and the frame go in the same direction. For cleaning wet ditches, heavy windrowing operations, faster finishing or cutting banks on a gentle slope.
How to use motor grader articulation
Before attempting articulation with your motor grader, read the operation manual to ensure safe operating procedures.
In articulation mode, you will use the joystick or levers to articulate the frame depending on the type of machine you have.
Machines with a joystick sometimes have automatic centring. This straightens the grader back to its default position.
There is also a screen or gauge in the cab that will show you the current articulation.
When turning, you can lean the wheels using your machine’s joystick or levers. This shortens your articulated grader’s turn radius and makes it more stable on slopes.
For turning right, lean the wheels to the right and articulate to the right. Vice versa for turning left.
There can be a tendency for the front of the machine to veer out of line. To correct this, articulate the rear module in the opposite direction. Then hold the machine in line, keeping an eye on both the tyres and the heel of the blade.
History of articulation in motor graders
In 1967, the construction world was awed by the JD570, developed by John Deere. In addition to front-wheel steering, the JD570 featured frame articulation. The machine could operate more efficiently, especially in confined areas, than any previously built grader.
The two steering methods combined let drivers “crab steer”, allowing for completely new uses. The grader’s front wheels could be articulated to move on slopes, on windrows and in ditches, while the back wheels stayed on solid footing.
The JD570 remained relatively unaltered until 1972, when it was only slightly modified and launched as the JD570A. Other manufacturers cottoned on, and soon all of them were offering graders with articulated frames in their lines.
For information about the range of refurbished Caterpillar 140G, 140H and 140K motor graders available from KH Plant, contact us online or call one of our representatives on +27 83 274 4882.
