GRAUPNER mc-16 Programming Manual page 197

Conversely, if the model hovers below the mid-point,
correct this by reducing the angle of attack appropri-
ately.
It may also be necessary to correct the carburettor
opening for the hover point (point "1") with "C1 
throttle".
This diagram shows only the change
to the hover point, i. e. collective
pitch minimum and maximum are
both left at -100 %
or +100 %.
Modify these settings until they really result in a con-
stant rotational speed over the full control range be-
tween hovering and climbing flight.
Descent setting
The descent setting should now be configured by plac-
ing the model in a steady descent from forward flight at
a considerable altitude by fully reducing collective pitch;
adjust the collective pitch minimum value (point "L") so
that the model descends at an angle of 60 ° ... 70 °.
Therefore, on the "Pitch" graph page, put the vertical
line on Point "L" by moving the pitch stick then change
this point's value appropriately with the selection keys
of the right four-way button.
This diagram shows only the
changes when setting the minimum
collective pitch value.
Once the model can fly this maneuver properly, set the
value for "Throttle min" – the value for point "L" on the
graph page for "C1  Throttle" – so that the rotational
speed neither increases nor decreases. This completes
the set-up procedure for throttle and collective pitch.
Some important closing remarks
Before starting the motor, ensure that the
+100%
throttle limiter is fully closed: this ensures that
the carburettor now responds only to the C1
trim lever. There will be a visual and an acoustic warn-
ing if the carburettor is open too wide when the trans-
-100% mitter is switched on. Otherwise, if the carburettor or
1 2 3 4 5
Control travel
speed controller is open too far when the motor starts,
there is a danger that the motor will run up to speed
immediately after starting, and the centrifugal clutch will
engage immediately.
Accordingly,
Nevertheless, if the motor is accidentally started with
the carburettor too wide open, the golden rule is this:
Hold the rotor head securely!
Instead, close the throttle limiter immediately, even if
this risks damaging the drive system (in the worst case
scenario).
+100%
Hover
point
The costs of repairing a clutch, a gearbox or even the
motor itself are negligible in comparison to the injuries
-100%
1 2 3 4 5
Control travel
and damage that an uncontrolled model helicopter can
cause if it is allowed to thrash about with spinning rotor
blades.
always hold the rotor head
firmly when starting.
Don't panic!
Don't let go!
YOU must ensure
the helicopter never moves
in an uncontrolled manner.
Always make sure no other person
is present in the
helicopter's hazard area.
The switchover from idle to a flight setting with in-
creased system rotational speed must not take place
abruptly. This will cause the rotor to accelerate very
quickly, resulting in premature wear to the clutch and
gear train. Since the main rotor blades are generally
mounted on a freewheeling unit, they will be unable to
keep pace with such rapid acceleration; they will re-
spond by swinging far out of their normal position and
may even cause a boom strike.
Therefore, after the motor is started, system rotational
slowly
speed should be increased by way of the throt-
tle limiter. If a switch has been assigned to the throttle
limiter, always ensure the »Control adjust«" menu,
page 116, is used to program a time constant of
about 5 seconds to run up system rotational speed
(opening the throttle limiter). Do not, however, program
a delay for closing the throttle limiter. Leave the default
value of "GL" in the "Type" column alone, however, to
configure this setting globally for all flight phases.
Program description - Helicopter mixer 197