Great Plains 3N-3020P Operator Manual - Manual (Page 33)

4/23/2010 196-248M
31 Adjustments
Second, the press wheels provide opener depth
control. The higher the press wheels run relative
to the double disks, the deeper seed will be
placed. To maintain a consistent depth, upward
press-wheel movement is restricted by an inde-
pendently adjustable stop on each opener. Refer
to “Opener Seeding Depth,” page 34, for informa-
tion on how to make this adjustment.
Coulter Adjustments
The drill is assembled so that when the coulters
are at two inches deep, the seeding depth is about
one inch. This is a good baseline setting for most
seeding operations. As field conditions warrant,
you can change settings on the entire drill or indi-
vidual coulters.
To prevent uneven seeding depth and excess opener
wear, run coulters at least 1 inch below seeding
depth.
Hydraulic Depth Control
Refer to Figure 12
The field-lift cylinder on the left transport wheel is
equipped with a hydraulic valve that regulates
coulter depth. Use the valve and knob shown to
adjust coulter depth.
Turn the knob clockwise to lower the coulters.
Each clockwise rotation will lower the coulters
about 3/32 inches. Make depth adjustments with
the implement slightly raised. After adjusting the
valve, raise and lower the implement several
times and recheck coulter depth.
The depth stop regulates depth on all coulters. If
the ends of either box run higher or lower than the
center, the field-lift system may be out of phase or
have air in it, or the frame sections may not be lev-
el. Refer to “Rephasing Lift System,” page 24,
“Bleeding Lift Hydraulics,” page 19, or “Leveling
Frame Side-to-Side,” page 21.
Weights
Transport Hazard. Adding more than the recommend
weight to the drill frame could cause a tire to blow dur-
ing transport, leading to a serious road accident and
personal injury. Do not add more than 2000 pounds to
the drill frame.
Raise Coulters
Lower Coulters
16271
Figure 12
Depth control adjustment