Great Plains NTA3007 Operator Manual - Manual (Page 96)

92 NTA907 or NTA3007 Table of Contents Index Great Plains Manufacturing, Inc.
166-371M Table of Contents Index 2012-07-02
Calibration for Manual Gearbox
Note: For drills with Variable Rate Kit installed, continue
at “Variable Rate (Servo) Calibration” on
page 95.
Complete step 1 through step 13 beginning on page 90.
14. Set gearbox (page 89): Remove the hairpin cotter
securing the gearbox adjustment crank. Rotate crank
until the control arm indicator points to the scale
setting that matches the rate from the seed rate
chart or as determined by any previous calibration of
a similar material for the same rate.
15. Re-insert the hairpin hairpin cotter.
16. Turn the calibration crank, for enough turns to be
sure the meter flutes are full and the system is
metering.
17. Stop cranking. Wipe meter doors. Empty the bag.
18. Push and then and then
to get to meter calibration.
19. On the seed monitor terminal,
set the monitor to Calibration mode .
enter [ 5 ] for the “# Meter Revs”, and
press the Start softkey .
This “# Meter Revs” parameter does not affect the
monitor calibration because the monitor counts
actual meter shaft revolutions and uses that count to
compute the Calibration Constant.
The “# Meter Revs” parameter is used for a progress
bar displayed during calibration.
20. Turn the hand crank to simulate meter operation for
1 ⁄
10
ha or
1 ⁄
10
ac. See table at right.
Note: It is important to turn the calibration crank rapidly.
Use a comfortable speed not exceeding
2 revolutions per second, which would simulate
10 km/h (6.2 mph) planting speed. A longer
calibration is always more accurate, especially for
low rates and small seeds.
1 ⁄
10
hectare is easy to
calculate and is a minimum calibration run.
See table at right for revolutions per area.
Note: For more accurate results, crank for a full hectare
or acre. With two people, the second person can
observe the revolution count on the seed monitor.
Machine Damage / Invalid Results Risks:
Rotate the calibration crank only in the:
CLOCKWISE direction on drill left, or;
COUNTERCLOCKWISE direction on drill right.
Operating in reverse can cause gearbox damage.
Note: The rate of the arm adjusting crank is more than
one scale degree per turn, and the crank can only
be pinned at quarter turns. Pin it when the
indicator is closest to the desired setting.
Calibration Crank Revolutions
NTA907 Contact Wheel
Revs/hectare 1050 1134
Per 1/10th ha 105 113
Jackshaft
NTA3007 Contact Wheel Jackshaft
Revs/acre 425 459
Per 1/10th ac 42.5 45.9