Case 845B VHP Operator's Manual page 102

Operating Tips
Articulated graders can be operated with the frame ARTI-
CULATED OR OFF SET (CRAB).
NON ARTICULATED frame is normally used for grading
large areas and for road maintenance and conservation.
With the frame ARTICULATED, the turning radius is re-
duced, making machine control easier in restricted areas.
In addition, a more precise control of material spreading
is permitted.
The OFFSET position permits the operator to maintain
the machine on firm ground when working in ditches, and
reduce the number of passes necessary to spread ma-
terial. This permits a better weight concentration, behind
the blade in severe operation conditions.
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CHAPTER 4 – OPERATING INSTRUCTIONS
ARTICULATED
OFF-SET
Although the grader permits the circle turn 360°, most of
the grading operations are done with the blade between
15° and 45° in relation to the work direction.
Increasing the angle of the blade reduces the side move-
ment of the material cut by the blade. However this per-
mits deeper cuts and more "severe" grading.
The change of the attack angle, blade pitch is also very
important for productivity.
Tilting the moldboard towards the front, eases the rolling
of the cutting material and allows still better spreading
and compaction of the material.
Tilting the moldboard towards the rear, permits higher
cutting action of the moldboard, but reduces the material
rolling along the moldboard.
The blade with the involute "ROLL-AWAY" profile main-
tains the capacity to roll material, with the top of the blade
inclined to the rear.
Changing blade angle while cutting, generates side forces
on the machine. These forces should be compensated by
leaning the front wheels and/or articulating the frame in
the direction of the blade cutting forces.
1. LEANED FRONT WHEELS
2. ARTICULATED CHASSIS
The angle change is only recommended during the cut-
ting, for machines equipped with phenolic resin plates
on the circle supports, in order to reduce the friction and
wear of the circle table.
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