Great Plains NTA2007 Operator Manual - Manual (Page 103)

Great Plains Manufacturing, Inc. Table of Contents Index Adjustments 99
2012-01-05 Table of Contents Index 166-372M
Marker Adjustments
Review “Marker Safety Information” on page 62 before
adjusting markers. There are four operating adjustments
for markers:
• Marker Extension: (page 100)
Once set for a specific row spacing, this only needs
periodic checking to ensure the clamp is secure.
• Marker Tension: (below)
You may want to adjust the spring tension to ensure
the markers track uneven ground, and do not drag
excessively when markers are folded.
• Disc Angle: (page 101)
(below) Even if your row spacing rarely changes, you
may need to adjust disc angle for soil conditions and
planting speed.
• Marker Speed: (page 101)
Once initially set by your dealer, this rarely needs
modification.
There are also two maintenance items for markers:
“Marker Hydraulic Bleeding” on page 134
“Marker Shear Bolt” on page 134
Marker Tension Adjustment
Refer to Figure 82
The strength of the mark is a function of marker arm
weight at the disc. A spring
behind the pivot assembly
acts against some of that weight. The spring is
adjustable, and may be used to increase or decrease
force at the marker disc.
The suggested initial marking force is 23 kg (50 lbs.). For
marking forces up to this value, use the weighing scale
included with the drill to lift the extended marker disc.
To adjust the marking force:
1. Fold the markers (page 62). This minimizes spring
tension for adjustment.
2. Set the marker hydraulic circuit to Neutral.
Shut off the tractor.
3. Loosen the eye bolt jam nut (on the top side of the
bracket).
4. Turn the adjust nut to change marking force:
Loosen this nut (relaxing the spring) to increase
marking force.
Tighten this nut (tensioning the spring) to decrease
marking force.
5. Tighten the jam nut to secure the new setting.
Impact / Crush / Pinch / Sharp Object Hazards:
Make all adjustments with tractor hydraulics shut down, and
the marker circuit in Float. Keep all persons clear of both
markers and their sweep arcs when testing adjustments. The
marker that moves may not be the one expected. A folding or
unfolding marker is a crushing hazard, and moving sharp
object hazard, that can cause serious injury or death. It has
multiple pinch points.
Note: If the marker spring force is set too low, the marker
may fail to return to its cradle when folded.
Figure 82
Right Marker Tension Spring
31198
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2
3
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2
3