Great Plains 3P4025AH Operator Manual - Manual (Page 56)

52 3P4025AH Table of Contents Index Great Plains Manufacturing, Inc.
411-099M Table of Contents Index 2014-07-29
Row Unit Down Pressure
Refer to Figure 40
The ideal amount of down-force causes the side gauge
wheels to compress any loose surface soil, but not press
a trench into subsoil.
To assess down-force, operate the planter for a short
distance on typical ground (with or without seeding), and
stop. Leave the planter lowered (row units in ground).
At several row units, inspect the furrow created by the
opener discs, but prior to furrow closing by the press
wheels.
Note: Be sure to inspect rows both in and out of tire
tracks.
Refer to Figure 41
1.
If the side gauge wheels are leaving no tracks, or
light tracks, increase down-force.
2. If the wheels are compressing trash and loose soil,
and leaving clear tracks right at the top of the
subsoil, down-force is probably correct and needs no
adjustment.
3. If the wheels are creating a trench into the subsoil,
down-force is too high and needs to be reduced.
Adjusting Down-Force
Refer to Figure 42
Row unit springs
provide the primary down pressure
necessary for row unit disks to open a seed trench. The
empty weight of the row units themselves contributes
about 130 pounds (59 kg) of the total force. When full of
seed, another 100 pounds (45 kg) is added.
The springs allow the row units to float down into
depressions and up over obstructions. Springs also
provide down force on coulters when using optional row
mounted coulters, and provide the primary down force on
row cleaners (optional), seed firmers (optional) and
press wheels.
Figure 40
Checking Furrow
31962
{
Inspect Furrow Here
Light or no side gauge
wheel tracks Insufficient down-force
Increase down-force
Gauge wheels compress
loose soil only Ideal
No adjustment required
Side gauge wheels
making deep tracks Down-force too high
Reduce down-force
Figure 41
Assessing Down-force
1
2
3
Figure 42
25 Series Row Unit Springs
31962
1
1