Great Plains 2420F Operator Manual - Manual (Page 36)

1520F, 2020F, 2420F, 1510HDF, &
2010HDF
8/14/2006
34
Seeding Rate
Adjusting the seeding rate requires the following:
1. adjusting drive sprockets,
2. setting seed-rate handle,
3. positioning seed-cup doors,
4. checking seeding rate.
Refer to the seed rate charts on page 37. These
charts list proper sprocket sizes and seed rate
handle settings for various seeds and seeding
rates.
The seed rate charts are based on cleaned, un-
treated seed of average size and test weight. The
charts are based on 9.5L x 15 rib implement tires
for 15ft drills and 11L x 15 rib implement tires for
20ft and 24ft drills.
Many factors will affect seeding rates including
foreign material, seed treatment, seed size, seed
weight, field conditions, and tire pressure. You
likely will need to make minor adjustments. Set
and check the seeding rate, then readjust the rate
as necessary.
Before setting the seeding rate, rotate the gauge
wheels. Check that seed cups and drive are work-
ing properly and free from foreign material.
Adjust Drive Sprockets
Install drive sprockets for the drive type for your
desired seeding rate.
For correct drive type, refer to seed rate charts be-
ginning on page 18. The charts list drive types as
1, 2, 3, or 4. Refer to the following table for the cor-
rect-sized sprocket for each drive type.
Drive Type Driver Driven Speed
Type 1 14 Tooth 44 Tooth Slowest
Type 2 24 Tooth 36 Tooth Two Times Faster
Than Type 1
Type 3 24 Tooth 24 Tooth Three Times Faster
Than Type 1
Type 4 24 Tooth 15 Tooth Five Times Faster
Than Type 1
To change drive sprockets, refer to Figure 5. Loos-
en idler plate (1) and remove drive chain (2) .
Remove lynch pins from shafts and rearrange
driver (3) and driven (4) sprockets.
Reroute drive chain over sprockets and idlers as
shown in Figure 5. Move idlers into chain so
chain has 1/4-inch slack in its longest span.
Tighten idlers.
17669
Set same drive type on both drill sections.
Set Seed Rate Handle
Position seed rate handle for each drill box as in-
dicated on seed rate chart. One handle is shown
in Figure 6.
To adjust seed rate handle, loosen wing nut un-
der handle. Slide handle until indicator is just past
the correct setting. Retighten wing nut.
Figure 5
Driver and Driven Sprockets
17618
Figure 6
Seed Rate Handle