Great Plains 2510HDF Material Rate - Manual (Page 7)

Great Plains Manufacturing, Inc. Main Box Seed Rate 5
10/19/2010 288-340B
Main Box Calibration
Refer to sample data and formulas at right.
1.
As necessary, convert your target seed population to
pounds per acre.
2. Set Drive Type, rate handle and seed cup door per
the earlier instructions.
3. Record weight of an empty container large enough
to hold seed metered for one acre for three rows.
4. Place several pounds of seed over three seed cups
on an outside end of a drill box. Pull seed tubes off of
these three openers and route them to container.
5. Raise the drill.
6. Rotate gauge wheel or calibration crank a few turns
to confirm gearbox has engaged and to confirm that
the seed paths are free from foreign matter.
7. Turn gauge wheel several times to fill seed cups with
seed. Turn wheel until seed falls from each cup.
Place seed collected so far back in the box.
8. Rotate gauge wheel until one acre has been tallied
(see table on page 2). Simulate field speed.
Note: You can also rotate the gauge wheel jackshaft by
means of a wrench or socket, on the drill side that
does not have the acremeter. When turning the
gauge wheel jackshaft, count tire rotations, as the
axle and jackshaft sprockets are not 1:1.
9. Check that the three seed cups have ample seed
coming into them.
10. Weigh metered seed.
11. Subtract initial weight of container (tare weight).
12. Divide by three.
13. Multiply by the number of openers on your drill to
determine total pounds seeded per acre.
14. If this figure is different than desired, set your seed
rate adjustment handle accordingly.
Note: You may want to repeat the calibration procedure if
your results vary greatly from seed rate chart.
When drilling, check seeding rate by noting acres drilled,
amount of seed added to drill and seed level in drill box.
If you are seeding more or less than desired, adjust
seeding rate slightly to compensate for field conditions.
For example:
Drill: 2510HDF-2910
Seed: Soybeans, 80,000 seed bag weight: 35 pounds
Target population: 210,000 seeds per acre
80000 ÷ 35 = 2286 seeds per pound
210000 ÷ 2286 = 92 pounds per acre
Drive Type: 3
Rate Handle: between 50 and 55, approximately 51
Assume empty ContainerWeight of:
2.5 pounds
From table, rotations per acre is:
214
For a 25-foot drill, tire rpm for 5 mph is:
52
Assume container plus seed weighs:
12.6 pounds
SeedWeight:
12.6 - 2.5 = 10.1
PoundsPerCup:
10.1
÷ 3 = 3.36
PoundsPerAcre:
3.36 x 29 = 97.5
Target was 92. Result is 6% high.
Adjust handle down by 3 (6% of 51)
to a Seed Rate Handle setting of:
48
SeedWeight TotalWeight ContainerWeight – =
PoundsPerCup
SeedWeight
3
-----------------------------
=
PoundsPerAcre PoundsPerCup OpenerCount Ч =