Great Plains P18432A Operator Manual - Manual (Page 21)

21 SLD
Operating Instructions
The SIMBA SLD is an amalgamation of
time proven, successful Simba design
components brought together to form this
important development. The SLD has been
designed to provide a one pass mix with
a fissured layer at disc depth for through
drainage and root access to lower horizons.
This enables rapid drainage and access after
rain, creating a greater effective capacity for
moisture compared to ploughing for the
same effective total depth of cultivation.
In principle, the machine is a tandem disc
with trip reset Pro-Lift tines, designed for
low draft, high speed operations. The
addition of a rear mounted roll enables
more effective cultivation in one pass. The
leading set of disc blades cultivate the top
horizon, minimising clod formation and
reducing tine loadings and blockage. This
starts the ‘top down’ cultivation process,
retaining weathered tilth in the surface level
for stale seedbed purposes. The trip reset
tines follow the disc blades to shatter at
depth retaining the surface intact to work
as a stale seedbed. This eliminates the
problem of ‘wet years’ in non-plough based
terms. The key to the SLD’s success is
the lower draft tine point and wing which
maintain shatter across the full width of
cultivation. The rear roll or trailing press
then consolidates the surface, cracks any
clods and firms the soil profile before/after
the rear gang completes mixing to depth.
The corrugated top and shattered lower
horizons are left fully weatherproof to any
conditions between cultivation and drilling
whilst retaining moisture below the surface
for rapid straw breakdown and optimum
establishment of the next crop.
4. Adjustment / Operation
4.2 Disc Units
The SLD features two rows of discs which
chop and mix the crop residue. A disc
spacing of 250mm ensures a fine tilth and
being arranged in a symmetrical format
around the centre line of the machine,
crabbing is eliminated, leaving the machine
to pull straight making the most efficient use
of the power available.
The discs fitted to the SLD are 610mm in
diameter (24”). They are manufactured
from heat treated chrome boron steel which
ensures excellent wear resistance and
enhanced working life.
Each disc is mounted on a Pro-Active sprung
leaf linked to a track rod system. Gang
angles can be varied with ease and accuracy
using a graduated adjuster.
Adjustable angling of the discs (between
10°-25°) ensures penetration and stubble
mixing are achieved in one pass. Working
depth can be varied simply via shimmed
adjusters. All this is achieved without
compromise to consolidation.
A level, evenly cultivated finish is maintained
by adjusting the balance of soil throw
between the front and rear disc.
Sprung leaves offer protection against
damage as well as offering a degree of
contour following as they flex up and down
in work.
The centre disc unit can be adjusted
independently of all other disc units to
ensure a level finish across the machine
width.