Great Plains ADC2350BE Operator Manual - Manual (Page 69)

Great Plains Manufacturing, Inc. Table of Contents Index Adjustments 65
2012-08-01 Table of Contents Index 167-085M
16. Subtract the calibrated rate per acre (or hectare)
from the target rate to determine a correction
difference.
17. Refer to the seed rate chart for Seed Rate gearbox
setting values for the target rate.
18. Determine the amount of rate change for each
degree of control arm rotation from the target setting.
If the calibrated rate was
higher than target (as in our example),
examine lower gearbox setting values.
If the calibrated rate was
lower than target,
examine higher gearbox setting values.
19. Adjust the control arm by the number of degrees
needed to adjust for the calibration difference.
The rate of the arm adjusting crank is more than one
scale degree per turn, and the crank can only be
pinned at quarter turns. Pin it when the indicator is
closest to the corrected setting.
20. Run the calibration again, starting at step 9, using
the new Variable Rate Gearbox scale setting.
This validates the gearbox adjustment, and
establishes a new, more precise Calibration
Constant.
21. With the present meter satisfactorily calibrated,
re-mount the final drive gear removed from the other
hopper.
22. Repeat the calibration procedure for the other
hopper, starting at step 1.
If only planting from a single hopper, see “Single
Hopper Operation” in the air cart Operator’s manual
for methods of disabling the meter on the hopper not
in use.
23. Remove and store the calibration crank.
Example: TargetRate = 67.6
RateDifference = 67.6 - 75.6,
which is: -8 pounds
The calibration run metered 8 pounds too much.
You must lower the gearbox setting to compensate.
RateDifference T etR
arg
ate CalibratedRate – =
56.9 63.7 34 82719
60.5 67.8 35 82843
64.2 72.0 36 82969
68.1 76.3 37 83099
72.0 80.7 38 83232
76.0 85.2 39 83369
TargetRate
Example:
Initial Variable
Rate Gearbox
Setting: 38
Example:
1 degree lower reduces rate by 67.6-63.9, or 3.7 lbs
2 degrees lower reduces by 67.6-60.4, or 7.2 lbs
3 degrees lower reduces by 67.6-56.9, or 10.7 lbs
Example:
The calibration difference was 8 pounds.
Adjusting down 2 degrees would correct by 7.2 pounds,
but adjusting by 3 would over-correct to 10.7 lbs.
So adjust the gearbox setting to just over 2 degrees
lower, to a final scale setting slightly below 36.