Great Plains 3PYPA Operator Manual - Manual (Page 72)

68 3PYPA Table of Contents Index Great Plains Manufacturing, Inc.
401-647M Table of Contents Index 03/20/2012
Row Unit Down Pressure
Refer to Figure 78
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 dis-
tance 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.
Null4:
Refer to Figure 79
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 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 Down-Force
Refer to Figure 80
Row unit springs
provide the primary down pressure
necessary for row unit disks to open a seed trench. The
weight of the row units themselves contributes about
130 pounds (59 kg) of the total force.
The springs allow the row units to float down into depres-
sions 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.
Null4:
Figure 78
Checking Furrow
29600
{
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
Null4:
Figure 79
Assessing Down-force
1
2
3
Null4:
Figure 80
25 Series Row Unit Springs
29600
1
1