Great Plains Uni-Press - Manual (Page 20)

WING FLOAT / CONTOURING
The main wing sections are capable of following contours by means of a pressurised
hydraulic system. A low pressure (approx. 10 to 20 bar) is set and held in the wing folding
cylinders automatically as the unfolding procedure is carried out. In the unlikely event that
this pressure needs to be adjusted refer to the following procedure.
To Adjust the System Pressure
PLEASE NOTE: - A low oil flow should be used, i.e., tractor tickover or low flow selected.
It is normal to
operate at 10-20 bar. This can be increased to 40-50 bar max, or reduced to 5
bar as conditions determine. Higher pressure will cause the wing tips to dig in causing the
centre of the machine to lift it out. Too little pressure will cause the wing tips to lift out & the
centre of the machine to dig in. When towing another implement behind the Press, the
pressure may need increasing to compensate.
In all cases the normal adjustment method is to minimise system pressure & then increase by
adjusting the pressure valve until the desired pressure is achieved.
In all cases, regardless of tractor make, adjustment should start from zero (minimum
pressure) and gradually increase up to desired pressure value.
With the machine off the ground,
1. Pressurise the wings to unfold. As the unfolding begins the pressure reading on the gauge
will drop. When the wings have fully unfolded the pressure reading will start to climb.
Keep pressurising the wings until the gauge has stabilised at the pre-set pressure. The
standard factory setting is 15 bar.
2. If the system needs adjusting:- Partially fold the wings & hold them in this position. To
adjust the pressure utilise valve 3 (shown below). Unscrew the adjusting screw until no
resistance can be felt (almost fully unscrewed position). Unfold the wings fully as before,
checking the gauge reading. Maintain hydraulic pressure unfolding wings & adjust the
screw whilst pressurising.
y Turning adjuster clockwise increases pressure.
y Turning adjuster anti-clockwise decreases pressure.
Once desired pressure is achieved lock the valve. As a check, partially fold the wings,
stop, and then unfold again maintaining pressure until the gauge stabilises at your desired
setting.
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