3 or more rotor blades ???

XXavier

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I thought the azimuth was represented on the horizontal axis, in degrees. I was asking about the +2 to -2 numbers.

Sorry... In the upper sketch, it's the deviation, in degrees, from the rotor plane, i.e., of a blade tip from the plane perpendicular to the rotor axis at the blade root. The flapping angle, as seen by an observer riding that axle. In the lower sketch, it's the deviation, (as seen from an observer riding the tip path-axis) of a blade tip from a plane passing through the blade root and parallel to the tip-path plane.
 
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Tyger

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Thanks... I would have thought it typically more than two degrees.
 
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Sorry... In the upper sketch, it's the deviation, in degrees, from the rotor plane, i.e., of a blade tip from the plane perpendicular to the rotor axis at the blade root. The flapping angle, as seen by an observer riding that axle. In the lower sketch, it's the deviation, (as seen from an observer riding the tip path-axis) of a blade tip from a plane passing through the blade root and parallel to the tip-path plane.
In a all floating rotor, I think that deviation would be 0 degree or every close to it since the rotor freely floats to the same plane of the blade tips. We can measure the angle between rotor and the mast to know if we in danger of striking anything.
 

XXavier

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In a all floating rotor, I think that deviation would be 0 degree or every close to it since the rotor freely floats to the same plane of the blade tips. We can measure the angle between rotor and the mast to know if we in danger of striking anything.

I don't think it works that way... In my opinion, the tip-path plane of a gyro rotor with a floating hub does also tilt back, exactly like a conventional, fully articulated rotor...
In both cases, the rotor 'floats freely', and the tip-path plane adopts a blowback angle, in one case because of the floating hub, and in the other by virtue of the flapping and lead/lag hinges that the blades have...
 

Jean Claude

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The tips plane of a rotor with a floating hub must be controlled by the ball swashplate like a helicopter.
The speed dissymmetry between the advancing and retrating sides produces a flapping angle between the swashplate plane and the tips plane.
 
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I wonder if it's possible to achieve the bottom graph on post #37 and keeping the upper graph a straight horizontal line through the use of a swash plate.
 

XXavier

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I wonder if it's possible to achieve the bottom graph on post #37 and keeping the upper graph a straight horizontal line through the use of a swash plate.

The floating-hub rotor head of the Doblhoff gyro/helicopter and of the gyro built by Chuck Beaty have no flapping or lead-lag hinges. Blade feathering was achieved by means of a spider, equivalent to a swashplate. The Doman helicopters did also have a floating-hub rotor head, with no flapping or lead-lag hinges. Feathering and collective were controlled with a swashplate.

Captura de pantalla 2021-01-21 a las 1.11.52.png
 
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C. Beaty

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As nearly as I can recall, Wolfy, 3 ea 11 ft blades of 5 inch chord on a gyro that flew at 425 lb AUW gives nearly 31 lb/ft2 of blade area. I still have that gyro stored in a shed, growing cobwebs.
All that green stuff is grass. If your cows were suddenly dropped off in Florida, they’d think they’d died and gone to cow heaven.
 
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wolfy

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Wow very lightly loaded I am impressed.
Yeah does look pretty nice over there mate, guessing with your near constant rain fall your green all year?

wolfy
 

C. Beaty

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With the Atlantic Ocean on one side and the Gulf of Mexico on the other, Florida doesn’t have temperature extremes but it does stay humid. We’re in the middle of the “dry” season so it doesn’t rain every day but the grass stays green.

 

Martin W.

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Fusion Copter is already working on the FC4, with 4 seats and 4 blades. They're not scared to post pictures ;)

View attachment 1151635

Interesting .... thanks ... !!!!

A 4 passenger production gyro would be a "first" in many ways.
Groen Bros built a 4 passenger but it did not go into production (Groen Hawk 4)

I am curious about the Fusion Copter specs ... they use two Rotax 912's for crew/cargo payload of 300kg (661 lbs)

While the Titanium Explorer uses one Rotax 912 for crew/cargo payload of 307kg (676 lbs)

 

Martin W.

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Also curious to see Fusion Copter adapt the double 2-blade teetering rotors in a + formation

Previous experiments in helicopters and the Wilford Gyro reveal that the 2-per-rev impulses fight each other with destructive results at the blade root (hub bar)

Mind you they had both sets of blades in the same plane ... whereas Fusion has them one above the other ... maybe that makes a difference , I dont know.

Anyway , its good to see the innovation by Fusion , and as I said earlier a 4 passenger gyro is a "big deal" in modern day.
 
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