Translations:Help:FAQ:Helisetup/9/en
Is it OK to leave it like this? What does this setting actually do?
When setting up the cyclic throw, you must/should always set exactly 6 degrees. The entire control loop is tuned to this value. If you set more or less, the predefined gain values, feedforward settings, etc., will no longer match. Of course, you can use a larger or smaller angle, but in that case you will most likely have to adjust parameters so the control loop does not oscillate and continues to operate properly.
Key rule: Always set cyclic throw to 6° cyclic pitch during setup.
The color of the status LED is only informational and indicates how much of the available servo travel is being used.
The more servo travel is used, the better, because this allows more sensitive and precise control. For good system performance, it is important that the status LED lights "as blue as possible", meaning a large amount of servo travel is used to reach the 6° cyclic pitch. If the 6° cyclic pitch is reached too early, this indicates that not all of the available servo travel is being used. As a result, control precision suffers because part of the servo’s resolution is lost.
With high-quality, precise and backlash-free servos, this may still work well even with limited travel (and Status LED not blue at 6° cyclic pitch). However, especially on small helicopters of the 250 to 450 class, this is often not the case, because the servos are usually not as accurate there and the mechanics often have considerable play in the linkages. So it is mandatory we see at least a blue light at this setup step. In any case, we recommend to mechanically increase the available control travel to exclude any possible issues from the beginning.
How to get a blue light?
This can be achieved, for example, by increasing the distance of the linkage point on the blade grip using longer balls, thus moving the linkage point further away from the rotor head’s rotation axis (feathering shaft). Alternatively, the ball links on the servo horn can simply be attached further inward. But with both of these options, note that the available collective pitch range is reduced. These measures therefore do not change the ratio between cyclic and collective pitch — both are reduced equally.
To change only the cyclic travel, shorter balls must be mounted on the inner ring of the swashplate. This moves the linkage point closer to the rotation axis so that a cyclic tilt of the swashplate results in less movement at the blade grip. Or, you can extend the balls on the outer ring of the swashplate, causing a given servo movement to produce less tilt of the swashplate. Of course, both options are often not as easy to implement as simply moving the linkage one hole further inward on the servo horn.