Cyclic ring:
Bron: http://www.vstabi.info/forum/read.php?26,61945,61971
Bron: http://www.helifreak.com/showthread.php?t=268182
Hi.
To shed some light on the CR:
First of all, it's not a ring, it's a double-truncated cone.
So, the more collective you add, the more the CR reduces cyclic travel.
When setting the CR in setup mode, you do not have the control loop active.
When checking in flight mode, the servos might do more travel then they will *ever* do in flight since the heli doesn't react to the control loop, the control loop is open. E. g. the roll or flip rate is limited naturally so the control loop won't oversteer in the air (where it has a feedback from the moving sensors).
In a full collective move, it's rather uncommon to bang the cyclic stick, even more so since even the hottest setup would certainly bog.
So, when you do the setup as instructed, AND when the other setup steps are within the given range of values (collective, cyclic), you are practically safe. Even if you can cause a situation where the mechanics would bind when on the ground.
There is no "hard limit" to the servo travels since this would affect flight behaviour badly, we (read like: you ) want to get our geometry right so everyhing works best.
— Eddi
Bron: http://www.vstabi.info/forum/read.php?26,61945,61971
Apart from eliminating binding at the extremes and at center collective, it also essentially sets a maximum pitch on the blades, which can prevent blade stalls. Blade pitch is equal to the sum of the collective pitch and the cyclic pitch; as you move collective to either side of center, the CR will reduce the maximum amount of available cyclic to keep the sum consistent.
Bron: http://www.helifreak.com/showthread.php?t=268182