Great Plains CPH-20 Operator Manual - Manual (Page 15)

13
Section 3 Adjustments
12/29/2011 CPH Center Pivot Hitch 148-152M
Great Plains Mfg., Inc.
Section 3
Adjustments
Coulter Down Pressure
The amount of coulter down force needed to cut a soil
groove varies with soil conditions. Adding weight or short-
ening the coulter spring increases coulter down pressure
and cutting force. Refer to Coulter Down Pressure, page
13, for more information on these adjustments.
Added Weight
In hard soil conditions where coulter penetration is limited,
you can add suitcase weights to brackets on hitch the
frame. Adding weight on the hitch frame provides the best
weight distribution for no-till drilling.You can add up to 100
pounds (45 kilograms) of additional weight per foot of hitch
width (1200, 1500 or 2000 pounds maximum). Place an
equal amount of weight on each weight bracket.
Figure 3-1
Weight Brackets
Coulter Springs
Coulter-spring length is preset at the factory to 10 inches,
giving coulters an initial operating force of 400 pounds
(181 kg). This setting is adequate for many difficult no-till
conditions. For lighter no-till conditions where rocks or oth-
er obstructions are a problem, you can reduce coulter
down pressure to give coulters better impact protection.
Refer to the following chart for adjusting coulter down
pressure.
NOTE: Do not reset coulter-spring length shorter than
9 3/4 inches (24.77 centimeters). Shortening springs
more than 9 3/4 inches (24.77 centimeters) may contribute
to premature failure of parts and warranty will be voided.
Seeding Depth
For accurate seeding-depth adjustments, you must adjust
your hitch and drill to match your soil conditions.
To adjust seeding depth:
1. Adjust coulters to desired depth. Refer to Coulter
Depth, page 13.
2. Adjust length of gauge-wheel turnbuckles on drill for
proper frame height. Refer to Leveling Drill, “Prepara-
tion and Setup,” in the drill operator’s manual.
3. Set lock plate on hitch level link to position that best
matches your field conditions. Refer to Lock Plate,
page 14.
4. Adjust hitch level link. Refer to Level Link Adjustment,
page 15.
Coulter Depth
A no-till coulter is mounted on the hitch directly ahead of
each opener on the drill. The coulters cut through heavy
trash and make a groove in the soil for the openers.
The center-pivot hitch is designed to allow coulters to pen-
etrate approximately two inches (5 centimeters) into soil
when the tongue is level. However, hard soil or heavy crop
residue may cause shallow penetration. If coulter penetra-
tion is different than desired, depth can be adjusted
hydraulically for all coulters or manually for individual
coulters.
Hydraulic Control
Make the following adjustment when drilling in level
ground with the seed box half full.
1. Retract tongue cylinder to transfer weight to coulter
toolbar.
2. Set tongue cylinder so that coulters are at desired
depth. Note setting on cylinder gauge (see Figure 3-2)
so that you can return to the same depth.
NOTE: Use cylinder gauge only as a reference. Gauge
does not measure actual coulter depth.
Figure 3-2
Cylinder Gauge
17212
Spring Length
Coulter Down
Pressure
10 1/2 in (26.67 cm) 175 lbs (79 kg)
10 1/4 in (26.03 cm) 300 lbs (136 kg)
10 in (25.40 cm) 400 lbs (181 kg)
9 3/4 in (24.77 cm) 525 lbs (238 kg)
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