Great Plains P17921E Operator Manual - Manual (Page 27)

27 UniPress
Operating Instructions
4. Adjustment / Operation
General Rules when Setting
the UniPress
• Run slightly tail low to give increased
clod cutting and consolidation in
harder conditions.
• In trashy conditions the use of the
levelling board may be limited due to
raking trash.
• Increase the rake angle of the levelling
board in spring time operation to carry
more soil for levelling.
• Reduce rake angle on levelling board
to hold soil and rub clod against clod in
harder conditions. This will also align
clods with the DD rings facilitating
better cutting.
The boards need to carry a certain amount
of soil to effect a levelling operation and also
to give a clod to clod crushing action.
When reversing the UniPress into corners
when working headlands ensure that the
levelling boards are fully raised and the
machine tilted onto the roll rings far enough
to allow the lower ends of the sprung leaves
to clear the ground.
4.6 Pitch Control
Pitch control on the UniPress is governed
by the quantity of shims fitted to the depth
stops attached to the drawbar cylinders.
Increasing the number of shims will lift the
front of the chassis when lowered into the
work position.
Running the UniPress level allows the press
rings to give an even consolidation and clod
crushing action, with the sprung leaves of
the levelling board aiding the clod crushing
action, aligning the clods for the roll rings.
Running the machine significantly nose
down or raised will reduce the load on the
rear axle leading to loss of drive of the axle
and then blockage, together with a reduced
consolidation effect.
If any roll axle starts to block regularly, this
is generally an indication that the roll axle
is not tight. Failure to keep the axles tight
results in loss of drive between each pair of
rings allowing rings to turn individually on
the axle. Should this occur the axle must be
tightened immediately to prevent any dam-
age occurring to the axle shaft.
If the roll axles start to block regularly this
may also be an indication that the ground
conditions are too wet for the UniPress to
be effective.
In practice it is possible to use the UniPress
on ground conditions that are unsuitable to
achieve the desired effect, and it is usually
possible to operate the machine without
regular blockage under such unsuitable
conditions, assuming that the axles are tight
and rings smooth.
As such, especially under wet conditions,
it is advisable to check on the cultivation
effect of the UniPress. Often the use of the
press 12 - 24 hours after the disc or longer
following the plough gives a far superior
surface consolidation effect.