Gregor99
Key Veteran
Location: Western Wa
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| That may work on a big heli but the King is just too small and light to counter the force of the tail.
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Size has nothing to do with it.
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| I see nothing wrong with an unlevel swash
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Breaking this into two parts as there are two primary forces and two typical remedies.
Fore/Aft With our heavy tailed Esky's this is the one we are most familiar with and usually caused by poor CG. Tilting the swash forward will stabilize the heli in steady hover. However to accomplish this, the neutral pitch position of the front of the rotor has more negative pitch that it would be required with a perfect CG. When you pull back on the right stick, the front of the rotor gets some positive pitch but not as much as it would with a perfect CG. The results across then entire rotor there ends up being more net negative pitch than if the CG were perfect. As result when you pull back on the right stick you now have to apply a little collective to compensate. If you go inverted, the heli response to the tilted swash is now reversed so you have to hold the right stick back twice as much to maintain a steady hover. I didn’t make this up, it came from Slider.
Side to Side The second most common swash correction is compensating for the thrust of the tail. If done to perfection the heli will hover hands off (or close to it) with the heli tilted to the right. This looks cool on video and of course is great feeling if all your going to do hover. But since hopefully all of will eventually do more than tail in over, we can quickly outgrow this perceived perfection. The problem with this setting is that is isn’t dynamic. If we could use a static setting to compensate for tail thrust, we could all be using rate gyros, or maybe even no gyro and simply using revo mixing. As the heli moves into forward flight weathervaning reduces the amount required tail thrust. The tilted swash now causes the heli to lean to the right. When you go inverted, the tilted swash is now working opposite of what it does in the upright flight. Instead of adding a little cyclic input to correct now you have to add a lot. Even in basic slow maneuvers I’ve noticed an unpleasant interaction. As I was working on my figure 8s in the garage I notice that when turning left, I had to fight the heli. Turning right it seemed fall into the turn very easily. As I looked closer during the left hand turns, the heli was already leaning to left. I had to first get it back to center then lean it right. In the right and turns, the heli was leaning right already, so very little input was needed. Moving to more level swash made the both turns more equal and the transitions, especially on the left turns feel much more natural.
By trying to perfect the balance of the heli by tilting the swash you are only correcting for one flight condition, steady hover. In other flight conditions, the titled swash causes imbalances approximately twice as bad as the original imbalance leaving the pilot to dynamically compensate for them. I'd rather have my heli balanced for most flight conditions instead of just one. I don't spend at of time hovering these days so I care very little if I need to add a little right stick to hold a position. I spend more time turning left and right, and level swash feels more natural.
Taking the road less traveled |
