The following pages are to assist in the proper setting of seeding rates
for the 2700 and 3000 Three-Point drill. The rates indicated in the
charts are approximate values. To assure the most accurate seeding
rate it is recommended that the drill be calibrated for the desired seed
at the time of planting.
Calibrating the seeding rate requires four steps: arranging
the drive sprockets, setting the seed-rate adjustment handle, positioning the seed-cup door, and checking the
seeding rate.
Refer to the seed-rate charts starting on page 6. These
charts list the proper sprocket sizes and seed-rate-handle
settings for various seeds and seeding rates.
The seed-rate charts are based on cleaned, untreated
seed of average size and test weight. The rates are based
on 9.5L x 15 rib implement tires. Many factors will affect
seeding rates including foreign material, seed treatment,
seed size, field conditions, tire pressure and test weight.
Minor adjustments likely will be needed. Set and check
the seeding rate using the procedures below, then re-adjust the rate as necessary.
Before setting the seeding rate, rotate the drive gauge
wheel to see that seed cups and drive are working properly and free from foreign material.
Change Drive Sprockets
Refer to Figure 1
3
Refer to the seed-rate charts for the correct drive
type–1, 1A, 2 or 2A.
To change the drive type
Refer to Figure 2
1. Loosen the idler-arm bolts and remove chains.
2. To change the double speed-change sprocket, remove nut and turn sprocket over.
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Figure 1
Drive Types
Idler
Spr
oc
ket
Idler
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9/9/2010
Figure 2
Double Speed-Change Sprocket
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Page 4
4
Refer to Figure 3
3. To change the jackshaft sprocket, remove the set
screws and slide the sprockets so the correct-sized
sprockets are aligned. Reinsert set screws.
Great Plains Mfg., Inc.
16412
Refer to Figure 4
4. Shorten orlengthen chainsas necessary and reinstall
chains. Be sure chain is installed with the chain connector link retainer towards the centerline and the clip
opening (split end) is facing the opposite way of the
chain travel. Move the idler arms into chains. See Figure 4 for correct chain slack.
Set Seed-Rate Handle
Refer to Figure 5
5. The position the handle for each drill box to the setting
indicated on the chart. One handle is shown. To adjust
the handles, loosen the wing nut under the handles
and slide until the indicator lines up with the correct
setting.
Figure 3
Jackshaft Sprocket
1/2
3/4
Figure 4
Chain Slack
In.
In.
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12927
Figure 5
Seed-Rate Handle
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Page 5
Great Plains Mfg., Inc.
5
Position Seed-Cup Doors
Refer to Figure 6
For wheat and other small seeds. move the seed-cupdoor handles to the highest position. For soybeans
and other large seeds, lower the handles to the second position. If excessive seed cracking occurs, lower
the handles to the third position. Move the handles to
the fourth, wide-open position for seed-cup clean out.
Make sure all handles are in the same position before
drilling.
13867
Figure 6
Seed-Cup-Door Handle
Check Seeding Rate
1. Record the weight of an empty container large enough
to hold the seed metered for one acre.
2. Place several pounds of seed over three seed cups on
an outside end of the drill box. Pull the seed tubes off
these three openers.
3. Raise the drill off the ground.
4. Turn the gauge wheel a few turns to fill the cups with
seed. Turn wheel until seed drops to the ground from
all three cups.
5. Place a container under the three seed tubes to gather the seed as it is metered.
6. Turn the drive gauge wheel until one acre has been
tallied on the acremeter (200 rotations on a 27-foot
drill or 182 rotations on a 30-foot drill). Check that
the three seed cups have plenty of seed coming into
them.
7. Weigh the metered seed. Subtract the initial weight
of the empty container. Divide by three for the
amount metered by each seed cup, then multiply by
the number of drill openers for the pounds-per-acre
seeding rate. If this figure is different than desired,
adjust the seed-rate handle and recheck the rate.
Note: If your results vary greatly from the charts, you
may want to repeat the calibration procedure.
When satisfied with the rate, set the same seeding rate
on the opposite drill box by repeating steps 1 through 3.
Small Seeds Attachment
To calibrate the seeding rate on the optional small seeds
attachment, follow these steps.
Refer to Figure 7
1. The proper small-seeds sprocket arrangement given different drive types on the main drill box. Arrange the sprockets on the small-seeds attachment
according to which drive type you will use on the
main drill box.
Note: For accurate metering on the small seeds attachment, the main drill box sprockets must be set to drive
type 1, 2 or 2A.
2. Set the seed-rate adjustment handle on the small
seeds attachment as indicated by the chart on
Small Seeds Attachment Seed Rate Chart, page 9.
3. Calibrate the small seeds attachment to your material by following the steps under Check SeedingRate, page 5.