Great Plains 1300 13-Foot Material Rate - Manual (Page 8)

6 1300 and 1300F Table of Contents Metric Charts Great Plains Manufacturing, Inc.
175-157B Table of Contents Metric Charts 2014-03-10
Main Box Seed Rate Calibration
Differences will exist between the tested seed and field
conditions used to generate the Seed Rate Charts, and
your seed and conditions. To accurately achieve your
target population, Great Plains recommends calibrating.
Perform the calibration with opener frames lowered (if
the openers are raised, the clutch disengages). Leave
the tractor hitched for movement control.
Estimate the sample sizes.
Take your planned population (in our example,
barley at 60 pounds per acre
and divide it by the row count of your drill
21 in our example.
The expected sample size is 2.9 pounds per row, or
8.6 pounds for 3 sample rows.
14. To perform this calibration, you need a scale that is
accurate near the aggregate sample size, and three
(3) light-weight containers, each capable of holding a
row’s sample.
15. Disengage the lock-out hub (see Operator Manual),
to permit independent rotation of the main jackshaft.
Refer to Figure 6
16. Remove the calibration crank from its storage stob
on the left top side of the main toolbar. Store the
retaining pin on the stob.
Refer to Figure 7
17. Place the hex socket of the crank on the left end of
the main jackshaft.
18. Pull the seed hoses off the top of three opener seed
tubes, at the top of the openers. Place the hoses into
each sample container.
19. If not already done, set the Drive Type, Seed Rate
Handle and Seed Cup Doors across the drill. If
fertilizer is loaded, remove the fertilizer drive chain
(unless you are simultaneously calibrating fertilizer
rate).
20. Load seed above the rows to be sampled. Load well
more than the expected sample size.
21. Rotate the crank several turns counter-clockwise to
ensure that the drives and seed cups are engaged,
working properly, free from foreign material, and that
seed is flowing steadily from the meters. Stop.
22. Note the current reading of the acremeter, unless
you do not plan to rely on it for the calibration.
23. Empty the sample containers back into the seed box.
24. Record the weight of the empty containers and place
them back under the three hoses to gather metered
seed.
Figure 6
Calibration Crank Stored
16651
Figure 7
Calibration Crank Engaged
16652
For example:
on a drill with a row spacing of:
7.5 inches
and row count of:
21
you desire to plant barley at:
60 pounds per acre
which, from the chart, is an initial Seed Rate Handle
scale setting of:
47 (interpolating from 50)
For example:
three empty 1.8 pound containers weigh:
5.4 lbs