Great Plains CTA4000 HD Operator Manual - Manual (Page 51)

Great Plains Manufacturing, Inc. Adjustments 47
2012-11-28 160-037M
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 61
1.
Raise the implement 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. 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 62 and Figure 63
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 is recommended for
conventional till and min-till conditions. Shorten it for
rows in tracks or no-till conditions. The minimum
recommended length is:
12
1 ⁄
4
inch (31.1 cm).
Figure 61
Pivot Point Bolt Holes
26427
2
1
3
1
2
3
Figure 62
Row Unit Spring Tension
17158
1
1
Figure 63
00HD Spring Length
26452
3
2
4
2
3
4