Great Plains 2N-3020 Operator Manual - Manual (Page 21)

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Section 3 Adjustments
2/28/08 2N-2420 and 2N-3020 Two-Section Folding No-Till Drill 196-164M-A
Great Plains Mfg., Inc.
Section 3
Adjustments
No-Till Seeding
To get full performance from your no-till drill, you need a
good understanding of coulter, opener and press wheel
operation.
Coulters. Drills with 10-inch row spacing are outfitted with
no-till coulters. Coulters are mounted independently and
directly ahead of each opener. The coulters cut through
heavy trash, making a groove in the soil. The coulters are
mounted directly on the box frame. Consequently, the cut-
ting depth of all coulters changes as the drill is raised and
lowered. The cutting depth of the coulters is controlled by
an adjustable hydraulic depth stop. Coulters that run di-
rectly in tire tracks can be lowered individually. Refer to
Coulter Adjustments, this page, for information on how to
make these adjustments.
Openers. Each opener is mounted on the drill with parallel
arms. This parallel-action mounting allows the openers to
move up and down while staying in-line with the coulters.
The parallel-action mounting also maintains the contact
point throughout the opener depth range. Opener double
disks widen the coulter groove, making a seed bed. The
down force needed to cut and widen the coulter groove is
supplied by two springs on the parallel arms. Adjusting
these springs changes opener down-force. Opener depth
is controlled by an adjustable side wheel. Refer to Opener
Adjustments, page 20, for information on how to make
these adjustments.
Press Wheels. To close the furrow, double-V press
wheels are attached to the rear of each opener. To provide
consistent seed firming, the press wheels are free to move
downward from their normal operating position. This sys-
tem maintains pressing action even if the opener is lifted
when the disks encounter obstructions. Press-wheel
down pressure is adjustable. Refer to Press Wheels, page
21, for information on how to make this adjustment.
Coulter Adjustments
The drill is assembled so that when the coulters are at 2
inches deep, the seeding depth is approximately 1 inch.
This is a good baseline setting for most seeding opera-
tions. As field conditions warrant, you can change settings
on the entire drill or individual coulters.
NOTE: Models with 7 1/2-inch row spacing are not outfit-
ted with coulters.
Hydraulic Depth Control
The master field-lift cylinder on the left transport wheel is
equipped with a hydraulic valve that regulates coulter
depth. Figure 3-1 shows the valve and knob used to adjust
coulter depth.
Turn the knob clockwise to lower the coulters. Each clock-
wise rotation will lower the coulters about 3/32 inches.
Make depth adjustments with the implement slightly
raised. After adjusting the valve, raise and lower the imple-
ment several times and recheck coulter depth.
The depth stop regulates depth on all coulters. If the ends
of either box run higher or lower than the center, the field-
lift system may be out of phase or have air in it, or the
frame sections may not be level. Refer to Lifting the Drill in
the Field, “Operating Instructions,” page 17, Bleed Field-
Lift Hydraulics, “Drill Preparation and Setup,” page 11, or
Leveling Adjustment, page 28.
Weights
If more weight is required for coulters to penetrate the soil,
weight brackets are available from your Great Plains deal-
er. Refer to Weight Brackets, “Options,” page 39 for part
numbers and ordering information.
Refer to the charts below for the results of adding weights
to your drill. Always add an equal amount of weight to each
box frame. Never add more than 500 pounds to each box
frame.
Figure 3-1
Left Transport-Wheel Cylinder with Depth-Control Stop
Raise Coulters
Lower Coulters
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