Great Plains 3S-4000HDF Operator Manual - Manual (Page 66)

62 3S-4000HD/HDF Table of Contents Index Great Plains Manufacturing, Inc.
195-067M Table of Contents Index 2013-06-13
Opener Height
The depth to which the opener disk blades penetrate the
soil is controlled in front by the tool bar and pivot (opener
height), and in the back by the press wheel height.
If the actual ground level is lower for some rows, such as
those in tire tracks, you can lower that row unit by
lowering the pivot point.
Refer to Figure 66
1. Raise the drill just enough to relieve tension in the
down-pressure spring.
2. Remove the bolt from the upper hole .
3. Re-position the arm at the lower hole , and secure
with bolt.
Note: No spring tension or position adjustment is
required if opener height is changed. The pivot
holes are designed for neutral effect on spring
tension. (The bolt at the top end of the spring uses
a hole
that depends on spring length, and not
opener height.)
Row Unit Down Pressure (Spring)
For planting in tire tracks, and for no-till conditions, you
can increase spring pressure on individual openers, or
all openers. Adjust the spring in conjunction with the
subframe down-force, and opener height, to keep the top
of the row unit parallel to the ground.
Refer to Figure 67 and Figure 68
To increase spring pressure:
1. Loosen jam nut at lower end of opener spring.
2. Tighten flange against spring tension.
Note: Each
1 ⁄
4
inch adjustment adds about 17 pounds of
force at opener disk (approximately 12 kg per cm).
3. After adjusting, lock flange nut in place with jam nut.
The length of the spring is factory-set to:
12
9 ⁄
16
inch (31.9 cm).
The reference points for this length are the
center of the upper/front clevis pin
and
the top edge of the lower/rear spring stop cup .
The factory preset length of 12
9 ⁄
16
inch is recommended
for conventional till and min-till conditions.
Shorten it for no-till conditions.
The minimum recommended length is:
12
1 ⁄
4
inch (31.1 cm).
2
1
3
Figure 66
Pivot Point Bolt Holes
26427
1
2
3
Figure 67
Row Unit Spring Tension
17158
1
1
Figure 68
00HD Spring Length
26452
3
2
4
2
3
4