Great Plains 3PNG15 Material Rate - Manual (Page 10)

202-553B 8/17/2006
Great Plains Mfg., Inc. 10
Native Grass Calibration
The Native Grass Box is for seeding fluffy, native grass
blends like Big Blue Stem, Indian Grass, and Side Oats
Grama.
We recommend that you test and adjust your drill using
the procedures listed below to help insure an accurate
seeding rate.
1. To adjust seeding rate, find out which sprocket ar-
rangement you have on the seed box; then decide
which sprocket arrangement is needed for native
grass unit (see seeding chart and sprocket arrange-
ments). To change sprockets on native grass unit, re-
lease idler arm and remove chain. Remove lynch
pins on driver and driven sprockets Rearrange
sprockets accordingly.
2. The pounds per acre in the seed charts are based on
drills with 9.5L x 15” rib implement gauge wheel tires.
Be certain that your tires are properly inflated.
3. After setting up your sprocket arrangement, com-
plete the following procedure to calibrate drill for your
specific seed type.
a. Record weight of an empty container large
enough to hold seed metered for one acre.
b. Fill three or more compartments at the outboard
end of drill box at least one half full. Pull seed
tubes off openers under the the compartments.
NOTE: For drills built after October 1, 2005, calibrate
using gauge wheel or supplied calibration crank. For
drills built before October 1, 2005, use gauge wheel to
calibrate or order the calibration crank kit available
through your Great Plains Dealer.
c. Raise drill off the ground. Be sure all safety lock
pins and/or blocking is in place.
d. To calibrate using gauge wheel, rotate gauge
wheel to see that feed cups and drive are work-
ing properly and are free from foreign matter.
e. To calibrate using calibration crank, attach cali-
bration crank to coupler on upper gauge wheel
jackshaft using retaining pin.
f. Turn gauge wheel or crank several times to fill
seed cups with seed. Turn wheel or crank until
seed falls to the ground from each cup.
g. Place empty container under the seed tubes to
gather the seed as it is metered.
h. If calibrating with gauge wheel, rotate drive
gauge wheel until one acre has been tallied on
the acremeter. This will be approximately 450 ro-
tations for the 12’ drill and 364 rotations for the
15’ drill.
i. If calibrating with calibration crank, use table on
below to determine number of rotations based on
drive type.
j. Check that the three seed cups have plenty of
seed coming into them.
Calibration Crank Revolutions per Acre
Drive
Type
Crank
Revolutions for
12’ Drill
Crank
Revolutions for
15’ Drill
1 302 245
1A 621 502
2 99 80
2A 203 164
23467
3PNG Calibration Crank