Great Plains 3N-3020 Material Rate - Manual (Page 5)

4/28/2004 196-366B
Great Plains Mfg., Inc. 5
Checking Volumetric Seeding Rate
The seed charts are based on cleaned seed and
12.5 x 15, rib implement transport tires and 13 x
5.00 - 6 contact drive wheel tires. Factors includ-
ing foreign material, seed treatment, seed size,
seed weight, field conditions and tire pressure will
affect seeding rate. Set and check the seeding
rate, then readjust the rate as necessary.
1. Record the weight of an empty container
large enough to hold seed from three seed
cups for one acre.
2. Place several pounds of seed over three seed
cups on an outside end of the drill box.
Refer to Figure 4
3. Turn contact drive wheel clockwise a few
turns to fill seed cups with seed and until seed
drops to ground from all three openers.
4. Place a container under the three openers to
gather seed as it is measured.
5. Turn contact drive wheel clockwise 420 revo-
lutions. Check to make sure seed cups have
plenty of seed covering them.
6. Weigh measured seed. Subtract initial weight
of empty container. Divide by three for the
amount measured by each cup, then multiply
by the number of drill openers for the pounds-
per-acre seeding rate.
7. If seeding rate is different than desired:
• Double check drive range sprocket combina-
tions.
• Check for seed cup malfunction.
• Check that all three rows are getting seed.
• Adjust seed-rate handle accordingly.
• Refer to “Troubleshooting,” in the operator’s
manual.
Equations for calibrating volumetric
measured seed empty container –
3 (number of cups measured)
------------------------------------------------------------------------------------------ pounds per cup =
pounds per cup number of openers × pounds per acre =
19114
Figure 4