To adjust the altitude increase or decrease the throttle accordingly. The speed of
the climb or dive is directly proportional to how far you move throttle out of its
centre position. The maximum climb and descend rate is controlled to 2 meters
per second.
Until the GPS Position Hold locks onto its position it is common for the
Draganflyer X8 to initially rise up to 3 meters (10 ft) and fall. It is also
common for the X8 to drift slightly with the wind them move back to the
position where the GPS lock was established. This adjusting process is
especially prevalent when the conditions are windy. To minimize these
effects in windy conditions maintain required throttle and pitch and roll control
briefly as the GPS Position Hold acquires lock.
Magnetometer Heading
Any helicopter must know its heading (which way it is pointing) in order to do a position
hold. The Draganflyer X8 uses a magnetometer (electronic compass) to sense the earth’s
magnetic field.
Earth’s magnetic field varies throughout the world. Therefore it is necessary to calibrate
the Draganflyer X8’s magnetometer for your location. If you are traveling significant
distances (100s of kilometers) with the Draganflyer X8, it may be necessary to recalibrate
the Draganflyer X8’s magnetometer. All calibrations can be conducted using the hand
held controller. If the Draganflyer X8 is not calibrated for your geographic location the
GPS position feature will (probably) not work properly.
A heading error of only a few degrees can degrade GPS position hold performance. If a
significant heading error is present the Draganflyer X8 will begin to fly in circles when in
position hold. If the heading error is greater than 45 ˚ these circles will grow bigger until
the Draganflyer X8 eventually crashes. If you notice the Draganflyer X8 flying in large
circles when in position hold mode, abort the GPS hold and fly in Altitude Hold.
Local interference is another source of heading error. Local interference refers to
magnetic fields that are generated by objects in your immediate environment. Possible
sources include electrical power lines, steel structures, and even anomalies in local
geology.
One simple way to detect if the magnetometer is out of calibration is to fly the helicopter
manually at several different headings. If you notice the heading drifts by large amounts
(15 degrees or more) or the Draganflyer X8 wants to spin in circles do not attempt a
position hold. You can try a different location to eliminate possible local interference or
try recalibrating the magnetometer.
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