Tuesday, September 23, 2008

Heli 3D: Collective Management, Rainbow & TicToc

Collective Management

This is one of the fundamental skill in 3D flying, thus I feel the need to start this entry trying to explain collective management, it is especially important in the next 2 moves that im going to talk about.

Ok, lets face it, our helicopter engine is not as powerful as we want it to be. Try to hold it at full load with high pitch over an extended period of time and one may notice that the power will start decaying (bogging). Also, you may have noticed that a particular heli with the same setup seems to be lots more powerful under the control of an expert pilot.

The experts didn't have any secret equipment/fuel on their heli, but they've mastered collective management.

So what does it mean to manage the collective well?
Think of collective management as singing or even doing sport that requires explosive power. We can't hold the high notes for long nor exert the super jumping strength continuously.
But if we give ourselves sometime to recover and breath, we would be able to perform again.
Our heli is not made of meat & blood, but they would appreciate that kind of 'respect' too.

To put into context of R/C heli, sudden punch from high RPM + high pitch = explosive power. Once the heli started shooting off, it should have enough momentum to continue traveling the intended path. Relax the throttle by reducing it gradually, and once you have reached the intended spot, the engine should be ready for another explosive power move again.

Sounds easy? haha no, timing is very crucial especially when giving 'gradual reduction' of throttle. This is the reason why only pro-pilots uses high pitch range (eg: +-13 on a 50 size heli), because they're able to time the sticks input correctly without bogging the heli.


Rainbow is good move for learning collective management.
1. Begin getting to 1st point (shown as the left most heli on the following picture) of rainbow by going from upright position to inverted via a backward flip
2. Just a second before the heli reaches the 1st point, reduce the throttle gradually (from positive to negative)
3. Once the heli reaches the 1st point, give full negative punch of throttle, this should shoot the heli to 3rd point (shown as right most heli).
4. Again, remember point '2', reduce the throttle gradually (from negative to positive) a second before reaching 3rd point.
5. Once at 3rd point, give full positive punch.

(Note: The above descriptions serve only as an example, it is not recommended to apply full stick all the time, unless you're into the 'pop' effect)

The 3 points of "Rainbow"

Tic Toc

Upright tictoc is sortof like rainbow, just that the tail is supposed to be fixed at one area.
Pretty much the same collective management skill required as rainbow, and fixing the tail at one spot requires precise timing in transiting from one point to another.

Aileron tictoc requires the same collective management skill too, the stick movements are kindof like doing half roll, rudder input would be required to move it around (tail pointing up would move the heli forward, tail pointing down would move heli backward). If the tail seems to move toward or away from the pilot, elevator input would be required to align the heli side-way.

Lastly, Ive made a video recording with stick movement (mode 1) of Rainbow, upright tictoc & traveling aileron tictoc.

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