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Old Dec 19, 2010, 07:47 AM
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Quote:
Originally Posted by djdavies83 View Post
Is coming where the tip of the blade is higher than it's centre?
The blades are pulled upwards all along their length by the aerodynamic lift, greatly corresponding to their pitch, airspeed (mostly propportional to RPM) and airflow from the rotor above or below it (air is a viscous fluid). The inner ends of the blade are fixed and lift the hub with them, while the tips are free -- within the limits of the blade-holders!! -- to rise. However the "centrifugal" (actually centripetal) forces of the blade, esp at the fast moving outer section, which are trying to go straight ahead (thank you for explaining momentum, Sir Issac) but are instead forced to circle around the hub, "pull" on the hub (the hub actually pulls the blade, and the blade resists) .... and the resultant of the lift and centripetal forces is a very flattened CONE!

THAT is the "coning angle", when viewing the rotating rotor disc edgewise.


Note: on very small & light helis it is possible to force the blades into a negative coning angle. I actually did this for a while with both this heli and the 3-ch 9008, but the added stability proved unworkable for the 5888, since their system was not designed for it! View some of the YouTube Chinese videos posted in the 5888 video-thread I started. When you free-frame you can see the proper coning angles, since the Chinese engineer (I am sure!) bent & adjusted the hub plates just as I have (the point of science & physics is that it should work universally: he & I both found this out independently!).



Lee
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