Great Plains 3P806NT Material Rate - Manual (Page 4)

2 3P806NT Table of Contents Main Box Rates Great Plains Manufacturing, Inc.
151-143B Table of Contents Main Box Rates 2011-10-21
Calibration Overview
Detailed calibration steps vary with each box, see:
“Main/Dual Box Seed Rate Calibration” on page 6,
“Fertilizer Rate Calibration” on page 31,
“Native Grass Rate Calibration” on page 17, and
“Small Seeds Rate Calibration” on page 24,
Some general information applies to all boxes, and is not
repeated in those pages referenced above.
Calibrate with Drill Raised
Perform the calibration with the drill hitched and raised.
Install lift-assist cylinder lock(s). Calibration with the drill
lowered is not recommended, as the drive tires in ground
contact prevent drive operation.
Calibrate for
1 ⁄
10
th
Acre or Hectare
The number of revolutions per area is:
Crank counts below 10 are not recommended. Sample
sizes may be too low, and fractional crank turns
introduce more error.
Calibration Crank Storage
Refer to Figure 2
The calibration crank
is found at the top front frame,
left of center, pinned to a stob on a 3-point weldment.
Note: The retaining pin at the stob can also secure the
crank to the jackshaft.
Using Calibration Crank
Place the hex socket of the crank on the right end of the
main jackshaft
.
Operate the crank clockwise
A wide range of cranking speeds produce accurate
calibrations. For reference, at 6 mph (10 kph) field speed,
jackshaft rpm is 65 (about 1 revolution per second).
Check Affected Boxes
Empty any boxes not being calibrated or remove a drive
chain to prevent undesired meter operation. Alternatively,
set rate handles to zero.
Figure 2
Calibration Crank
28410
2
1
revolutions for Crank Tire
Full Acre 656 1170
65.6 117
Full Hectare 1622 2890
162 289
32341
1/10 th Acre
1/10 th Hectare
1
2