Great Plains PT1230 AA1080 Operator Manual - Manual (Page 23)

21
Section 3 Adjustments
4/12/05 PT1230 Pull-Type Folding Planter 401-069M-B
Great Plains Mfg., Inc.
Section 3
Adjustments
Planting Rate
Transmission Adjustment
To change the planting population, change the sprocket
combination on the transmission.
1. Refer to Planting Rates for Finger Pickup Corn
Meters, page 22, or Planting Rates for Brush Meters,
page 23, for proper sprocket combination for your de-
sired planting population.
2. Remove cover from transmission by loosening knob
on cover. See Figure 3-2.
3. Loosen carriage bolt and flange nut on idler plate. Ro-
tate idler plate and move idlers out of chain.
4. Remove chain. Place correct sprockets for desired
planting rate on shafts. Store all unused sprockets on
storage bracket.
5. Reroute chain over idlers and sprockets.
6. Turn idler plate counterclockwise to take up all but 1/4-
inch slack out of chain. Retighten carriage bolt and
flange nut on idler plate.
7. Replace transmission cover and hand tighten knob.
2-to-1 Drive Reduction
The charts on page 22 and page 23 are based on a 15-
tooth, driven sprocket in the contact-wheel drive. To re-
duce planting rates by one-half, switch to 28-tooth sprock-
et. See Figure 3-1.
Figure 3-1
2-to-1 Drive Reduction
Checking Planting Population
After setting transmission, always field check planting
population as follows.
1. Release spring pressure on closing wheels or disks.
2. Tie up closing disks or wheels to hopper support using
a chain or heavy wire. Lock up optional Seed-Lok
wheels.
3. Adjust 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.
If the planting population is significantly different than de-
sired, make the following checks.
• Double check the sprocket combination in the trans-
mission. Refer to Planting Rates for Corn Meters,
page 22, or Planting Rates for Brush Meters, page 23.
• Check air pressure in the gauge-wheel tires. Refer to
Tire Inflation Chart, “Appendix,” page 62.
• Check for meter malfunction or excessive contact-
drive-wheel slippage. Refer to “Troubleshooting,”
page 38.
16863
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