Great Plains CTA4000 Operator Manual - Manual (Page 45)

Adjustments 41
08/03/2010 160-269M-A
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 48
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 re-
quired. 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 no-till conditions, you can
increase spring pressure on individual or on 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 49 and Figure 50
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 13 pounds of
force at opener disk (approximately 9 kg per cm).
Do not tighten nut more than one inch (2.5 cm).
3. After adjusting, lock flange nut in place with jam nut.
The length of the spring is factory-set to:
13 5 ⁄
16
in (33.8cm).
The reference points for this length are the
center of the upper/front clevis pin
and
the base of the lower/rear spring stop cup .
The factory preset length is recommended for conven-
tional till and min-till conditions. Shorten it for rows in tire
tracks or more difficult min-till conditions. The minimum
recommended length is:
12 5 ⁄
16
in (31.3cm).
Figure 48
Pivot Point Bolt Holes
26382
2
1
3
1
2
Figure 49
Row Unit Spring Tension
17158
1
1
Figure 50
00 Series Spring Length
26454
3
2 4
2
3
4