* UPDATE. It's just simple Physics. The wobble only happened in heavy windy conditions. Some have said I am wrong, but offer no solutions. I simply tightened my blades up to be more snug (one was looser than the other) and the wobble completely went away! It is obvious to most that in my explanation, that the downwind blade has no wind resistance and is flying faster than the wind, so it stays straight out. When it comes the upwind into the wind, it is feeling resistance of the wind, and pushed back slightly when the blades are too loose, as the main shaft is trying to turn it. It cant possibly lead, so it lags. The blades don't have to be so tight not to move, but enough to overcome the wind in high conditions.
And this IS a modern helicopter compared to the EH 1 heli I compared it to, not to flybarless helis that I also have owned and flown extensively.
Slow RPM, is zero to what ever hovers, and no more. My EH 1 turns only 1000 RPM with fixed rotors and does not wobble at that slow speed. I do not take off in 3d, high rpm mode typically. Tightening the very loose blades fixed my wobble, so it is hard to argue with success.
Again, even with perfectly manufactured blades and being perfectly balanced, with head speeds around 1250, the folding blade that is advancing into the wind, gets slightly pushed back by wind resistance, making it not in line, compared to the other blade.
This allows the rotor disc to be slightly out of balance, thus the wobble. In 3d mode, around 2500-2600 rpm, the centrifugal force is so high, the blade stays closer to actual alignment and symmetrical, so it does not wobble where you can see it. The more the wind, the more the misalignment, and the more the wobble. Others have many other words for it, but us old time heli fliers called it wobble. Tightening the blades can help reduce the wobble at low head speeds so before you knock it, try it first. Thanks for watching and subscribing.
Dave Herbert
~NightFlyyer~
AMA L-8221
Негізгі бет My Helicopter wobbles? Here's why! Tightening my blades fixed it.
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