YP1225A and YP1625A
Sprocket Indexing (Stagger)
Great Plains |
401-625B | 6/19/19
15
10. Check the position of the rear row sprocket. The
tooth tip at, or just ahead of the index mark must be
the tooth called for by the chart. If not, release spring
and re-mount chain.
11. Repeat step 4 through step 10 for each row pair.
12. Re-install seed discs and meter covers.
Fine Adjustment Indexing
If, after indexing, the side-to-side seed stagger is still
considerably uneven, it is possible to make small
adjustments that may correct it. Imbalance can occur
over time as row unit chains wear and stretch.
The Indexing charts provide columns for alternate rear
row sprocket alignments. These settings move the
placement of the rear seed drop. The amount of
movement is given as a percentage (
20% or
40%) of
the in-row seed spacing.
Adjustments are made only to the rear row timing.
•
Advancing the timing (dropping the seed sooner,
moves the seed position back).
•
Retarding the timing moves the seed position
forward.
If an adjustment is made, test it on one row pair before
adjusting the entire planter.
1. Make sure the current front sprocket index is 1, and
the current rear sprocket index number matches the
“Initial” number in the indexing chart for the
population being planted.
2. Measure the actual stagger at the rear row seeds.
3. Determine by how many inches (or cm) the rear
seed placement needs to move in order to be
centered between the front seed placements.
4. Determine the percent of seed spacing, and whether
advance or retard, required to adjust the rear seed
drop to the desired spot.
5. In the tables (thumbnail view below), find the new
rear sprocket tooth setting for the percent retard or
advance desired.
29717
Example:
The front sprocket is “1”. At a target population of 31,500
seeds/acre, the rear sprocket is at tooth “17”.
At this population, spacing in a single row is 13.3 inches.
The rear row seeds would be ideally at 6.6 inches ahead or
behind the front row seeds.
We find that the rear seeds are being placed 1.5 inches
behind the front seeds.
We need to move the rear seeds back another 5.1 in.
A 40% advance is 5.3 inches at this seed spacing.
Moving the rear sprocket from tooth 17 to tooth 18 provides a
40% advance.
acre
hectare
acre
hectare
Retard
Advance
Retard
Advance
31 500
77 838
26 250
64 865
17
14
1
4
18
32 000
79 070
26 667
65 895
17
14
2
11
18
32 500
80 310
27 083
66 924
5
14
2
8
18
33 000
81 540
27 500
67 954
5
18
5
8
14
33 500
82 780
27 917
68 983
2
18
17
15
14
34 000
84 020
28 333
70 013
1
18
17
12
14
34 500
85 250
28 750
71 043
1
3
9
12
14
These Columns are for Fine Adjustment Only
Twin Row 30in
Twin Row 36in
Seeds per
Seeds per
40% Rear Seed Drop
Adjustment
Initial Rear
Tooth
Number
20% Rear Seed Drop
Adjustment
