Great Plains 2SNG30 Material Rate - Manual (Page 3)

8/17/2006 202-499B
Great Plains Mfg., Inc. 3
Calibration
Note: Seeding rates will vary greatly with variations in
sizes of seeds. Although the seeding rates listed in this
manual are based on an average seed size, we recom-
mend you test and adjust your drill using the following
procedures to help ensure an accurate seeding rate.
NOTE: For drills built after October 1, 2005, use
gauge wheel tire or supplied calibration crank to cali-
brate. For drills built before October 1, 2005, use
gauge wheel to calibrate or order the calibration crank
kit available through your Great Plains Dealer.
NOTE: The calibration crank is only for use with the
2SNG drills. Only the 2SNG drills will come equipped
with the calibration crank.
1. To calibrate, use either gauge wheel or supplied
calibration crank. If using calibration crank, attach
crank to coupler on upper jackshaft drive with re-
taining pin and disengage lockout on drive wheel.
2. Raise drill off the ground.
3. Rotate gauge wheel or calibration crank to see
that seed cups and drive are working properly, not
binding, and free from foreign material.
4. To adjust your seeding rate, first you must decide
which sprocket arrangement you need. To change
sprockets, remove nut on the double speed
change sprocket and turn sprocket over. Loosen
the idler arm bolt, put chains on and tighten both
bolts. (The lengths of the chains will need to be ad-
justed in order to make this change.)
5. There are many factors which will affect seeding
rates, including seed treatment, weight of seed,
size of seed, surface condition of seed and tire
configuration, pressure and slippage. Minor ad-
justments will probably be needed to compensate
for these factors.
6. The pounds-per-acre in the seed charts are based
on drills having 9.5L x 15" implement gauge wheel
tires.
7. The large differences in seed size and treatment
can cause a wide variation in actual seeding rates.
The seed rate charts on the following pages are
based on average size seed. This may differ from
the seed you are using. Use the seed rate charts
as a guide. Set the pounds-per-acre desired at the
indicator number for your row spacing and com-
plete the following procedure to calibrate the drill
for your specific seed.
a. Record weight of an empty container large
enough to hold seed metered for one acre.
b. Place several pounds of seed over three of the
seed cups at the outboard end of the drill box.
Pull the seed tubes off of these three disk open-
ers.
c. Turn gauge wheel or calibration crank a few
turns to fill the cups with seed. Turn wheel or
crank until seed drops to the ground from all
three cups.
d. Place a container under the three seed tubes to
gather the seed as it is metered.
e. To calibrate using gauge wheel, turn gauge
wheel until one acre has been tallied on the
acremeter (182 rotations on a 30’ drill or 225 ro-
tations on a 24’ drill).
f. To calibrate using the calibration crank, use
chart below to determine number of revolutions
based on drive type. Turn calibration crank se-
lected number of rotations for drive type.
g. Be sure to check the three seed cups to make
sure each cup has plenty of seed coming into
them.
Calibration Crank Revolutions per Acre
Drive
Type
Crank
Revolutions for
30’ Drill
Crank
Revolutions for
24’ Drill
1 122.5 151
1A 251 310.5
2 40 44.5
2A 82 101.5
23467
2SNG Calibration Crank