Great Plains 3PYPA Operator Manual - Manual (Page 73)

Great Plains Manufacturing, Inc. Table of Contents Index Adjustments 69
03/20/2012 Table of Contents Index 401-647M
An adjuster cam sets down pressure individually for
each row unit. This is useful for penetrating hard soil and
planting in tire tracks. For best results always adjust trac-
tor tires so they are not ahead of 30in or 70cm rows.
Refer to Figure 82
Use only enough down pressure to cut the seed trench
and maintain proper soil-firming over seed. Excessive
row unit down force will lead to premature wear on row
unit components, uneven seed depth and gauge wheel
slippage.
Refer to Figure 81 (shown at cam setting 2),
Figure 82 and Figure 83
To adjust down pressure, use a 1
1 ⁄
8
in (29mm) open end
wrench or the tool stored under the walkboard.
1. Raise the planter. Although this adjustment can be
made with the planter lowered, the springs will be in
tension, and will require more effort. The extra force
required may also damage tools.
2. Install lift cylinder locks.
3. Put tractor in Park and shut it off.
4. Position wrench on the fixed nut near or slightly
forward of vertical.
5. Pull upper spring link back.
6. Move the adjustment cam to the new setting on
the spring adjust bar .
Note: Do not set all rows higher than notch four. Using
high settings across all rows causes uneven plant-
ing. Individual rows may be set higher if running in
tire tracks.
Null4:
Figure 81
25AP Series Row Unit
Spring Adjustment
29605
3
5
2
2
Cam Notch Pounds Kilograms
zero (out of notch) Lock-Up & Maintenance
one 235 105
two 260 120
three 295 135
four 355 160
five 415 190
six 475 215
tip Do Not Use
29831
Null4:
Figure 82
Row Unit Minimum Cam (at 1)
27065
4
6
3
Null4:
Figure 83
Row Unit Maximum Cam (at 6)
27065
4
5
2
6