Great Plains CALIBRATION CRANK Assembly Instructions - Manual (Page 4)

152-302M 10/4/2005
Great Plains Mfg., Inc.
Calibration Crank Kit 4
Calibrate
Refer to Figure 2
1. To adjust seeding rate, decide which
drive type (gearbox) setting you need
from the seeding charts. Set the gear-
box.
2. Record weight of an empty container
large enough to hold seed metered
for one acre.
3. Place several pounds of seed over
three seed cups on an outside end of
drill box. Pull seed tubes off of these
three openers.
4. Attach calibration crank to gauge
wheel jackshaft and secure with re-
taining pin. Disengage lockout on the
drive wheel. Rotate crank a few turns
to confirm clutch and gearbox are en-
gaged.
5. Rotate calibration crank to see that
feed cups and drive are working prop-
erly and are free from foreign matter.
6. Turn crank several times to fill seed
cups with seed. Rotate crank until
seed falls to the ground from each
cup.
7. Turn crank 935 rotations. This is equal
to one acre.
8. Check that the three seed cups have
plenty of seed coming into them.
9. Weigh metered seed. Subtract initial
weight of container. Divide by three.
Multiply by the number of openers on
your drill to determine total pounds
seeded per acre. If this figure is differ-
ent than desired, set your seed rate
adjustment handle accordingly.
NOTE: You may want to repeat the cali-
bration procedure if your results vary
greatly from seed rate chart.
Equations for calibrating seed rate:
measured seed - empty container
3 (number of seed cups measured)
= pounds per seed cup
pounds per seed cup x number of openers = pounds per acre
23389
Figure 3
Calibrate