Great Plains 3S-3000F Operator Manual v2 - Manual (Page 42)

40
Section 3 Adjustments
3S-3000 Three-Section Folding Drill 195-110M-A 11/9/07
Great Plains Mfg., Inc.
Seeding Depth
General Description
The 3S-3000 has double-disk openers with depth-control-
ling press wheels mounted on floating opener frames.
This system provides accurate depth control and seed
placement over uneven terrain. When used with live
closed-center tractor hydraulics, the drill provides con-
stant opener down pressure through a wide range of
opener movement. The following is an introduction to the
seeding components and how they work.
Double Disk Openers
Each opener is mounted on a floating opener frame.
Opener bodies are staggered for easy soil flow. Long and
short opener bodies provide for 7" of stagger for planting
through residue. All openers pivot on a common axis to
maintain consistent depth as opener frames follow con-
tours. A single spring provides down pressure necessary
for the double disks to open a seed furrow. The spring al-
lows openers to float down into depressions and up over
obstructions. Individual openers can be adjusted to ac-
count for tire tracks. Refer to page 42 for individual opener
adjustment instructions.
Press Wheels
A press wheel is attached to each opener body. Press
wheels provide two important functions.
First, press wheels close seed furrows and gently press
soil over seed. To provide consistent seed firming, press
wheels are free to move down from normal operating po-
sition. This maintains pressing action even if opener disks
encounter obstructions or hard soil.
Second, press wheels control seeding depth. To maintain
a consistent depth, the relationship between the bottom of
the opener disks and press wheel is fixed upwardly by an
adjustable stop on each opener. The position of the adjust-
able stop determines how deep seed is placed. Raising
the stop increases seeding depth. Lowering the stop de-
creases seeding depth. Refer to page 42 for press wheel
adjustment.
Floating Opener Frames
Each drill section has an opener frame which pivots about
the centerline of the drill gauge wheels. These floating
opener frames have the ability to rock the openers 15 de-
grees up and 15 degrees down as a group. By pivoting at
the gauge wheels, openers maintain a consistent depth as
opener frames rock up and back.
Down pressure for each opener frame is provided by two
cylinders working on a constant lever arm. When com-
bined with live hydraulics, cylinders provide constant down
pressure across the width of each opener frame – regard-
less of how the frame is positioned. Two cylinders per
opener frame along with special trunnions also provide
some ability for one end of an opener frame to rock inde-
pendent of the other while maintaining constant opener
down pressure across the frame. A pressure-control valve
on each circuit allows you to adjust down pressure.
The opener frame has one adjustment point for two differ-
ent operating positions – one for drilling with normal down
pressure and another for drilling with high down pressure.
Refer to Opener Frame Adjustments, page 43.
00 Series Opener Down Pressure
!
DANGER!
Crushing hazard – You will be seriously injured or killed if you
are caught between raising openers and drill frame. Always
stop tractor engine, set park bake, and remove key before ad-
justing or servicing openers. Keep all bystanders well away
during drill operation.
!
WARNING!
Escaping fluid under pressure can penetrate the skin causing
serious injury. Avoid the hazard by relieving pressure before
disconnecting hydraulic lines. Use a piece of paper or card-
board, NOT BODY PARTS, to check for suspected leaks. Wear
protective gloves and safety glasses or goggles when working
with hydraulic systems. If an accident occurs, see a doctor im-
mediately. Any fluid injected into the skin must be surgically re-
moved within a few hours or gangrene may result.
Opener down pressure controls opener penetration and
press-wheel soil firming. Use only enough down pressure
to cut a furrow and maintain proper soil-firming over seed.
Excessive opener down force may cause bulldozing of the
openers in light soil conditions, and will lead to premature
wear on opener components.
The following chart shows the approximate force at the
openers for a given pressure at the pressure control valve.
Gauge
Setting
Pounds Force at Opener Disks
6 inch rows 7-1/2 inch rows 10 inch rows
200 PSI 87 92 99
300 PSI 96 103 113
400 PSI 105 113 128
500 PSI 113 124 142
600 PSI 122 135 157
700 PSI 131 146 171
800 PSI 140 157 186
900 PSI 148 168 200
1000 PSI 157 178 214
1100 PSI 165 189 229
1200 PSI 174 200 243
NOTE: To account for additional compaction from
drill and tractor tires, set pressure on center section
openers slightly higher than wing section openers.