Lu,
"... Lockheed CL-475 ... the gyro was a circular ring that was mounted around the rotorhead."
This is the system i am really interested in, since it was basically just a gyro augmenting a rigid rotor in a light helicopter. Mechanically very simple, with no need for power assist.
"... 186 ... was so stable and flew so well that the Lockheed designers decided to scale up the dynamic system ..."
Shows system works on a medium size machine. A modern implementation of this would clearly be electronic with laser gyros and electric linear actuators.
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Nick,
"The "power assist" could very well be electric ... the cost could be down to $2000 ..."
Agreed for a medium heli, but why introduce more active systems on a light heli trainer?
"... stabilizer bar ... specifically ignores pilot input unless the input is held long enough. This means that mechanical stability systems almost always reduce plot controllability and control response as necessary costs of their use."
Ah, you're getting confused with the Bell system here. The Bell-bars were designed to supply attitude inertia into the teetering rotorhead, to "low pass" pilot input. IMHO it is a bad system and should not be considered. The Lockheed system did not affect rotor attitude inertia, but just put an attitude reference into the system - as Lu highlights, control was exceptional.
"As I said before, I see no reason to make complex mechanical systems (stabilizer bars, dual rotors, specially designed flapping hinges, etc) to achieve ease of control and high stability."
Agreed, but if we take (say) a Sikorsky/Schweizer 300, then i am just talking about a single gyro in (say) the swash plate mech. That $2000 would be overkill on this modification, and (provided a CL475 type mech) the control would be exceptional.
Due (only) to limited finances i have only had an introduction to the R22. Most of the flying was suprisingly similar to gliding, once you retrain your feet (no collective but there is an airbrake lever). Mastering the hover was clearly going to ingest to much cash for my tastes, hence this thread...
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Dave,
"... feathering the retreating blades, however, logic, and others, suggest that this reverse velocity should be utilized by putting the blades on the retreating side into a negative pitch."
I'm not against this, but am convinced that you can never get close to the optimum downwash distribution using this technique. This goes for conventionals, coaxials, intermeshers and interleavers. For a start you will always get upwash (fountain effect) in the circle (rotor planform) of zero velocity. The alternative is the V22...
Just in case it is reverse velocity utilisation that has lead you to the tri-teetering hub, check out Widgeon's post (especially the links to the pics) in the thread:
http://www.pprune.org/forums/showthr...83#post1923883
Mart
[Edit:ammendments]