Great Plains YP1625A Operator Manual - Manual (Page 65)

Great Plains Manufacturing, Inc. Table of Contents Index Adjustments 61
2013-08-13 Table of Contents Index 401-625M
Row-Unit Down Pressure
Row-unit springs provide the down pressure necessary
for row-unit discs to open a seed trench. The springs
allow the row-units to float down into depressions and up
over obstructions. Springs also provide down force on
coulters when using optional row mounted coulters.
You can adjust down pressure individually for each
row-unit. This is useful for penetrating hard soil and
planting in tire tracks. For best results always adjust
tractor tires so they are not ahead of 30 inch or 70 cm
rows.
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. Excessive down force will also
cause uneven seed depth.
Refer to Figure 70 through Figure 72
To adjust down pressure, use 1
1 ⁄
8
inch (29 mm) open
end wrench or tool stored under the walkboard.
Position wrench on nut and pull back and down. Move
adjustment cam to new setting. If using cast tool
stored under the walkboard, be sure row unit is off the
ground to fully relax springs.
Minimum and maximum settings are indicated by
position of adjustment cam. Each notch on adjustment
cam will increase the down pressure on the row-unit
springs. Use the table below as a setting reference.
Note: Do not set all rows any higher than notch 4. Using
settings above this on all rows will create uneven
depth control and improper function.
Spring Down Pressure
Individual rows may be set higher if running in heavy tire
tracks.
Figure 70
Row Unit Cam Operation
29605
1 3
Figure 71
Cam Minimum Setting (1)
27065
2
3
1
2
3
Figure 72
Cam Maximum Setting (6)
27065
Cam Notch Pounds Kilograms
zero (out of notch) Lock-Up & Maintenance
one 320 145
two 355 160
three 385 175
four 435 200
five 485 220
six 535 245
tip Do Not Use