Adjustments During The First Flight, Blade Tracking - GRAUPNER Jet Ranger Handbuch

6. Adjustments during the first flight
6.1 Blade tracking
„Blade tracking" refers to the height of the two rotor blades when they are spinning. The
adjustment procedure aims at fine-tuning the pitch of the main rotor blades to exactly the same
value, so that the blades rotate at the same level.
Incorrectly set blade tracking, with the blades revolving at different heights, will cause
the helicopter to vibrate badly in flight.
When you are adjusting blade tracking you are exactly in the „firing line" of the blades. In
the interests of safety you should keep at least 5 metres away from the model when you
are doing this.
You can only check blade tracking if you are able to see clearly which blade is higher and which
is lower. The best method is to mark the blades with coloured tape as follows:
There are two alternative methods: figure „A" shows the use of different colours on the blade
tips; fig. „B" shows the use of the same colour, but applied at different distances from the blade
tips.
Procedure for adjusting blade tracking
1. Set the helicopter to the point where it is almost lifting off, then sight directly along the rotor
plane.
2. If you can see clearly that the rotor blades are running in the same plane, no adjustment is
required; however, if one blade is running higher than the other, the settings must be
corrected.
3. Locate the pushrods between the swashplate and the mixer levers (4618.150); the
adjustment is made at the ball-links on both ends of these pushrods: unscrew the links to
raise the blade, screw them in to lower it.
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Jet Ranger