Great Plains PT1230 AA1062 Operator Manual - Manual (Page 32)

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Section 5 Planting Rate Adjustments
10/10/12 PT1230 Pull-Type Folding Planter 401-069M-A
Great Plains Mfg., Inc.
Planting Rate
Transmission Adjustment
To change planting population, change the sprocket com-
bination on the transmission.
1. Refer to “Planting Rates for Finger Pickup Corn
Meters” on page
32 for the proper sprocket combina-
tion for your desired planting population.
2. Remove the cover from the transmission by loosening
the knob on the cover.
Left-Hand Planter Transmission
Figure 5-1
16861
3. Loosen the carriage bolt and flange nut on the idler
plate. Rotate the idler plate to move the idlers out of
the chain.
4. Remove the chain. Remove sprockets currently on
transmission shafts.
5. Find the correct sprockets on the storage brackets
and place on the transmission shafts.
NOTE: When not in use, store all extra sprockets on the
storage bracket.
6. Place the sprockets on the drive/driven shafts.
7. Re-route chain over idlers and sprockets.
8. Turn the idler plate to take up chain slack. Chain
should have a maximum of 1/4-inch slack.
9. Retighten the carriage bolt and flange nut to secure
idler plate.
10. Replace the transmission cover and hand tighten the
knob.
2-to-1 Drive Reduction
The 15/28 tooth drive sprocket located on the inner side of
the contact drive wheel assembly will give you a 2-to-1
drive reduction and reduce planting rates by about one-
half.
NOTE: After each sprocket combination adjustment, make
a field check to be sure you are planting at the desired
rate.
16863
2-to-1 Drive Reduction
Figure 5-2
Checking Planting Population
After setting the transmission or contact-drive reduction,
always field check the planting population as follows.
1. Release spring pressure on opener disks and wheels.
2. Tie up closing disks and wheels to hopper support us-
ing a chain or heavy wire. Pin up optional Seed-Lok
wheels
3. Adjust the planting depth to a shallow setting.
4. Plant at a normal speed for a short distance.
5. For 30-inch rows, measure 17 feet 6 inches (one-thou-
sandth of an acre.)
6. Count the number of seeds in one row over the mea-
sured distance.
7. Multiply the number of seeds counted by 1000. This
gives you total population.
Example
• 30-inch row spacing
• Measure 17 feet 6 inches
• 24 seeds over measured distance in one row
24 X1000 = 24,000 plant population per acre
If the planting population is significantly different than the
desired, make the following checks.
• Double check the sprocket combination in the trans-
mission. Refer to the “Planting Rates for Finger
Pickup Corn Meters” on page
32.
• Check air pressure in the gauge wheel tires. Refer to
Tire Inflation Chart, “Appendix” on page 63.
• Check for meter malfunction or excessive contact-
drive-wheel slippage. Refer to “Section 6 Trouble-
shooting” on page
39.
Section 5
Planting Rate Adjustments