Great Plains 3N-4025P Operator Manual - Manual (Page 113)

Great Plains Manufacturing, Inc. Table of Contents Index Adjustments 109
2014-01-29 Table of Contents Index 196-538M
20P Series Row-Unit Adjustments
Refer to Figure 149, which depicts a 20 Series row unit fully
populated with all features supported on 3N-4020P drill
(excepting Seed-Lok
®
). From front to back, they are:
1. Dual Down-Pressure Springs & Cam (Standard)
See “20P Series Row-Unit Down Pressure” on
page 110. Each row-unit is mounted on the planter
with parallel arms. This parallel-action mounting
allows the row-unit to move up and down while
staying horizontal. A cam
adjusts the force
between 100 and 225 pounds.
2. Double Disk Openers (Standard)
A pair of canted opener disk blades
open a furrow
and keep it clear for the seed tube. These disks are
adjustable for contact. See “20P Series Row-Unit
Down Pressure” on page 110.
3. Side Depth Gauge Wheels (Standard)
These wheels
are the primary control of seeding
depth (set by the T-handle). They also have
adjustments for angle and disk contact. See “Side
Gauge Wheel Adjustments” on page 111.
4. Shut-Off Cap (Standard)
Disable rows for alternate row spacing. “Row Unit
Shut-Off” on page 79.
5. Singulating Seed Meter (Standard)
6. Seed Tube (Standard)
A seed tube mounted between the disks (not shown)
delivers seed to the trench. It is fed by the seed
meter, and has a seed flap
, shown here cut back
for clearance from the seed firmer. See “20P Series
Seed Firmer Adjustments” on page 113.
7. Seed Firmer (Optional)
An optional seed firmer (Keeton
®
shown) minimizes
seed bounce and improves soil contact. See “20P
Series Seed Firmer Adjustments” on page 113.
8. T-Handle (Standard)
This handle
sets the height of the side depth
gauge wheels. See “20P Series Row-Unit Planting
Depth” on page 110.
9. Press Wheels (Standard)
The press wheels close the furrow, gently pressing
the soil over the seed to ensure good seed to soil
contact for even emergence. They have adjustments
for down-pressure, stagger and angles. See “20P
Series Press Wheel Adjustments” on page 114.
Certain Machine Damage:
Do not back up with row-units in the ground. This will cause
severe damage and row-unit plugging.
Figure 149
20 Series Row Unit
34191
1
5
8
2
3
6
9
4
9
7
1
1
1
1
1