Great Plains 1007NT Material Rate - Manual (Page 24)

Great Plains Mfg., Inc.
22
150-290B 07/08/2009
Note: If you are planting a mix similar to mixes planted in
the past with this drill, set the Drive Type and final
sprocket for the previous mix.
10. Note the current reading of the acremeter, unless
you do not plan to rely on it for the calibration.
11. Rotate crank or gauge wheel for one tenth acre or
hectare.
12. Check that the three seed cups have plenty of seed
coming into them.
13. Calculate the area rate at current drill settings.
Weigh metered seed, and subtract the initial weight
of the container. Divide this number by 3 (number of
cups metered). Multiply by the number of openers
(which is less than 15 if using alternate spacing)
14. If the measured rate is within 3% of your desired field
rate, no further adjustment is necessary. Skip to step
20.
The rate just measured is used to locate a new setting in
the Native Grass Cup Rate tables on page 24.
15. Calculate the revolutions needed for the target field
rate. Multiply the calibration revolution rate by the
ratio of desired to measured seeding rate. Divide the
rate just measured by the cup revolution rate (from
the tables) at the current drill settings.
Figure 8
Native Grass Driven Sprocket 20T
28379
2 Area Sampled Wheel Revolutions
Full Acre 491.6
49.2
Full Hectare 1214.8
121.5
1/10 th Acre
1/10 th Hectare
For example, gross weight of containers & sample is:
2.45 lbs
The net weight (pounds) is:
0.95 = 2.45 - 1.5
The pounds per seed cup per acre is:
3.17 = 10 x 0.95 ÷ 3
The SampleRate pounds per acre is:
47.5= 3.17 x 15
PoundsPerSeedCup 10
NetWeight
3
---------------------------- × =
SampleRate PoundsPerSeedCup 15 × =
NetWeight GrossWeight EmptyContainer s
( )
– =
In our example, the 47.5 lbs/ac rate is 148.4% of the
desired 32 lbs/ac rate, or 48.4% high. An adjustment is
indicated.
For example:
Drive Type 2, 20T Driven, and no Rate Reduction is a
cup shaft rate of:
103.78 RevolutionsPerAcre
The shaft rate needed for the target field rate is
69.9 = 103.78 x 32 ÷ 47.5
FinalRevs RevolutionsPerAcre
FieldRate
SampleRate
---------------------------- Ч =