20 series openers – Great Plains 3N-4025P Operator Manual User Manual
Page 40

3N-4010P, 3N-4015P, 3N-4020P and
3N-4025P
196-286M
4/23/2010
38
Closing Disk
For proper seed-to-soil contact, the closing disks
must have enough down pressure to close the
seed trench without unnecessary soil
compaction.
Refer to Figure 36
To adjust down pressure on closing disks, ratchet
spring cam to next cam height by turning head of
support bolt (1) clockwise.
20 Series Openers
Opener Down Pressure
Refer to Figure 37
Opener springs provide the down pressure nec-
essary for opener disks to open a seed trench.
The springs allow the openers to float down into
depressions and up over obstructions.
You can adjust down pressure individually for
each opener. This is useful for penetrating hard
soil and planting in tire tracks.
Use enough down pressure to cut the seed trench
and maintain proper soil-firming over seed. Ex-
cessive opener down force will lead to premature
wear on opener components.
Figure 37
20 Series Opener with Meter
Opener spring
Disk
18273
Figure 36
Closing Disk and Tube Holes
20338