Great Plains NTA3007HD Operator Manual - Manual (Page 97)

Adjustments 93
04/04/2011 166-207M
Frame-Mounted Coulter Force
In normal operation at target running depth, the spring is
at full extension or only slightly compressed. It com-
presses briefly as obstructions and denser soil are
encountered.
Coulter springs are set to 181 kg (400 lbs). In normal
operation at target running depth, the spring is at full
extension. It compresses briefly as obstructions are
encountered.
• In heavy no-till conditions, you may observe the
springs in compression most of the time. This means
that the blades are not reaching the desired coulter
depth. If drill weight is available, you can increase the
spring down-force to compensate.
• In light but rocky conditions, the factory spring setting
may be higher than needed. You can extend blade life
by reducing the force at which the blades ride up over
obstructions.
To adjust the coulter spring:
Refer to Figure 100
1.
Raise the drill and install transport locks. See “Rais-
ing” on page 33.
2. Determine the new spring length desired. See the
table at right.
3. Measure the current length of the spring(s) to be
changed. If already shorter than 24.8cm (9
3 ⁄
4
in), or
longer than 26cm (10 1 ⁄
4
in), do not further adjust
them.
4. Loosen the jam nut .
5. Rotate the adjuster nut until the spring is at the
new length. Tighten the jam nut.
Note: If all springs are continuously in compression, the
coulters can lift the wing frames off the ground (at
the gauge wheels), resulting in uneven coulter
depth and/or uneven seed depth. If the drill is al-
ready operating at maximum down-pressure, re-
duce coulter depth.
Null4:
Null4:
Do not use spring lengths shorter than 24.8 cm (9.75 in). It
may contribute to premature parts failure which will not be
covered by warranty.
Figure 100
Frame-Mounted Coulter Spring
27139
Spring Length Force at Blade
26.0 cm (10.25 in) 136 kg (300 lbs)
25.4 cm (10.00 in) 181 kg (400 lbs)
24.8 cm (9.75 in) 238 kg (525 lbs)
1
1
2
3