Great Plains 3N-4020 Operator Manual - Manual (Page 82)

78 3N-4010F/3N-4010HDF/3N-4020F Table of Contents Index Great Plains Manufacturing, Inc.
196-359M Table of Contents Index 2013-10-29
10HD Row Unit Down Pressure
Refer to Figure 102
The ideal amount of down-force causes the press wheels
to compress any loose surface soil, but not press a
trench into subsoil.
To assess down-force, operate the drill for a short dis-
tance on typical ground (with or without seeding), and
stop. Leave the drill lowered (row units in ground).
At several row units, inspect the furrow created by the
opener discs and closed by the press wheels.
Note: Be sure to inspect rows both in and out of tire
tracks.
Refer to Figure 103
1. If the press 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 sub-
soil, 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 10HD Row Unit Down Force
The springs allow the row units to float down into depres-
sions and up over obstructions.
With Frame-Mounted Coulters
With frame-mounted coulters, the seed trench is prima-
rily opened by the coulters. Row unit springs provide only
additional assistance needed to make a furrow “V”
shaped and ensure furrow closure by the press wheels.
Often, the rows may be run at the minimum spring set-
ting, other than in tire tracks, which commonly need
some adjustment.
If trench depth is not being achieved across all rows,
adjust the force and/or depth of the coulters before mak-
ing row unit spring adjustments.
With Unit-Mounted Coulters (or no coulters)
Without frame-mounted coulters, the row unit springs
provide the primary down force for cutting through resi-
due and opening the seed trench.
Figure 116: 10HD Series:
Checking Furrow
27064
{
Inspect Furrow Here
Light or no press wheel
tracks Insufficient down-force
Increase down-force
Press wheel(s) compress
loose soil only Ideal
No adjustment required
Press wheel(s)
making deep tracks Down-force too high
Reduce down-force
Figure 117: 10HD Series:
Assessing Down-force
1
2
3