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it may be necessary to shift both gangs across so as to transfer the weight away from the side
dipping in.
Wheel set-up
There are a couple of points regarding the setting of the wheel for depth. If the wheels are right
in the air whilst cultivating, all the weight of the frame bears on the gang frames. If the plough
is digging in one side the gangs would need to be adjusted so that the weight of the frame is
on the side which is not digging in. This can only be done within the bounds of the amount of
offset of the machine to the tractor. On the converse side, if the machine is being carried on
the wheels, the frame can be moved so that it carries the side digging in more and stops it
diving in. Remember to always set the wheels at the same position. Setting at ground level
works better than right in the air. If you don’t set the wheels at the same position each run your
setting is different and it make it difficult to work out what your other changes are doing. If the
tractor has a float position then this can be used to keep wheel depth constant.
Tractor behaviour
Should the tractor pull any way but straight, after the machine has been set correctly in a level
position, then the reason can always be contributed to the amount of drag set up by the discs
passing through the ground. This drag can vary to a great extent because of the condition of
the soil eg. wet, dry, sand, clay. As it would be impossible to give an answer to all these
situations, due to the large variation in soil, we will provide the following example:
The machine, when set up correctly, is found to be pulling the tractor badly to the left hand
side. The correction method used in this instance was to slide the draw bar to the extreme right
hand side of the pull bar, resulting in the desired tracking of the tractor. A tractors incorrect
pulling behaviour would be due to an uneven working pressure on the discs and by trying the
following methods there will be a solution, which will correct the tractor’s direction so it will
maintain a straight line to the direction of travel.
a) Check the gangs are set at the correct angles
or
try an alternate angle (refer (d))
bearing in mind the closer you have the gangs at 90
to the frame the lesser the
penetration.
b) Place the draw bar in different positions along the pull bar and vary the angle with each
setting until the optimum is achieved
c) Evenly adjust springs either up or back along the pressure screw. This step is used to
transfer more work to either the front or rear gangs, by digging the discs deeper into the
ground, thus increasing the drag on one or the other gang. When this work is shared
evenly between the two gangs, the tractor will cut straight and true. To increase the
work load of the front gangs, fit the pressure screw in the hole position on the wheelkit
axle (see next section).
d) If you do not wish your machine to have an uneven penetration, e.g. back gang cutting
deeper than the front gang or vice-versa, as described in (c), then the drag is also
affected by the angle of the disc. The greater the angle, the greater the drag, the less
the angle, the less the drag and penetration. So adjusting the angles is another
alternative.
Increasing penetration
As mentioned above (c), greater penetration by the front gang can be achieved by running the
pressure screw in the hole position (rather than the slotted position). When the wheels are
lifted off the ground there will be a transfer of weight from the tractor to the front gang. The
higher the lift the more pressure is created and the greater the front disc penetration. However
this can also affect how true the machine runs and therefore other alterations may need to be
made (see above). Always set the wheels at the same position to ensure each job cuts the
same depth.
