Great Plains 606NT Operator Manual - Manual (Page 35)

Great Plains Manufacturing, Inc. Table of Contents Index Adjustments 31
2014-02-10 Table of Contents Index 151-061M
Coulter Adjustments
Refer to Figure 29
A no-till coulter
, is mounted directly ahead of each
opener on the drill. The coulters cut through heavy trash
and make a groove in the soil for the openers.
The coulter is designed to operate with its spring at full
extension. The spring is briefly compressed as the disc
encounters and rides over difficult obstructions.
Coulter Depth
Great Plains recommends operating at a tool bar height
of 24
3 ⁄
4
in. (62.9 cm). Small adjustments may be
required for unusual seeding depths and as coulter discs
wear. If the coulters are not reaching desired depth (and
the springs are uncompressed), the drill may need more
weight (page 30).
Drill-wide coulter depth is controlled by tool bar height.
The coulters are mounted on the drill frame. Group
coulter cutting depth changes as the drill height is raised
and lowered.
Note: When the opener frames are running level, the
opener disc depth is
1 ⁄
4
in. (6 mm) above coulter
depth.
Tool bar height is set by the tractor hitch for 3-point drills,
and by cylinder depth stop (page 18) for pull-type drills.
Individual Coulter Depth
Refer to Figure 29 and Figure 30
Individual coulter depth may be adjusted by raising and
lowering the spring bar
.
1. Determine the new coulter depth desired, and/or the
difference between that and the current depth.
2. Raise the drill until the coulter discs are just touching
the ground. The press wheels are supporting some
row unit weight at this point.
3. Measure the current spring bar length , from
bottom of tool bar to bottom of spring bar. For
reference, the factory setting is:
12
1 ⁄
2
± 1 ⁄
8
in. (31.8
±3 mm)
Determine the new bar length required.
4. Loosen the clamp bolts . Use a mallet to adjust the
bar height. Re-tighten the clamp bolts to Grade 5
torque specification.
Figure 29
Frame-Mounted Coulter
18645
1
3
4
2
1
2
Figure 30
Coulter Spring Bar
32612
T O
9
C
3
6
5
Seeding Depth Risk:
When adjusting coulter height, also reset opener spring force
(page 34). Changing the coulter height changes the distance
between row unit and spring attachment.
3
5
5
6