Great Plains NTA2007 Operator Manual - Manual (Page 99)

Great Plains Manufacturing, Inc. Table of Contents Index Adjustments 95
2012-01-05 Table of Contents Index 166-372M
Row Unit Spring Adjustment
Row unit springs normally require no adjustment. The
factory setting for the row unit springs is:
In some unusual conditions, rows in tire tracks may need
to be set heavier.
1. Make adjustments with the wings unfolded and the
rows lifted off the ground, so that the springs are at
full extension.
2. Loosen the jam nut . Rotate the adjuster nut .
Shorten spring to increase down-force; lengthen
spring to reduce down-force.
For each turn of the adjuster nut, the down force at
the opener disc changes by approximately:
1.7 kg/turn (3.7 lbs/turn)
3. Re-tighten jam nut after setting force.
Disc Blade Adjustments
Opener disc angle and stagger is not adjustable, but
disc-to-disc spacing is, and may need attention as discs
experience normal wear. Spacers will need to be reset
when blades are replaced.
Refer to Figure 75
The ideal spacing causes the blades to be in contact for
about 25 mm (1 inch). If you insert two pieces of paper
between the blades, the gap between them should be
0 to 44 mm (0 to 1.75in).
If the contact region is significantly larger or smaller (or
there is no contact at all), it needs to be adjusted by
moving one or more spacer washers. If the contact
region varies with blade rotation, one or both blades is
likely bent and in need of replacement.
Spring length 324 mm (12
3 ⁄
4
in)
Assembly length 562 mm (22
1 ⁄
8
in)
Machine Damage Risk:
Do not use spring lengths shorter than 29.8 cm (11
3 ⁄
4
in).
It may contribute to premature parts failure not covered by
warranty.
Figure 74
Row Unit Spring
29427
1
2
3 4
1
2
3 4
Figure 75
Checking Disc Contact
26447