Single blade rotor!

[Sapientino]

do you now this?
http://www.lidak.it/

it is italian and regurarly flying
it has several patent since it has solved all problem connectet to single bladed rotor. I know mr lidak personally and he 's a genius!
this copter is power with two Moto Guzzi fuel injected engines and now he's planning to produce it
it has also a revolutionaty variable idraulic power trasmission to tail rotor

[Jan Verhoeven]

Concept dates from late 50's, early 60's; developed to produce a light and easy hover trainer, as well as a testbed for the GRP MBB BO-105/BK-117 rotorblades that came with the famous Titanium rigid rotorhead. Also the tailrotor was single bladed.

http://avia.russian.ee/helicopters_eng/bo-102-r.html

http://avia.russian.ee/helicopters_eng/bo-103-r.html

[Rotor Rooter]

Sapientino

Can you tell us more about this interesting helicopter?

It appears that the only US patent by Vladimiro Lidak is #6,619,585 for 'Helicopter single-blade rotor'. This is the patent that Al Hammer mentioned on the forum a few months ago.

Thanks;
Dave

[Sapientino]

Sapientino

Can you tell us more about this interesting helicopter?



one of the most interesting thingh is that has two 90 hp indipendent engine (I mean it can fly with only one safely )
another is that blade is made of wood/composite
this prototype is flying great since 1998 and now he is building a certified version for production.
it is also revolutionary the fact that with idraulic trasmission of tail rotor, the tail rotor doesn't change pitch but only revs!
mr Lidak says that his single blade proved to be 15% more efficient than double blade
I was thinking about using this concept on a gyro!

[Rotor-Head]

What is the benifit, other than only buying one blade at a time rather than two?

[Rotor Rooter]

Sapientino;

Thanks for the additional information.

Your friend's patent should go a long way in reducing the 1/rev. vibration created by unbalanced thrust.
Do you know if Vladimiro Lidak had a problem with unbalanced drag? And if so, what he did to reduce it?


Rotor-Head;

On a helicopter, the fewer the blades, the more efficient the rotor. The implication is therefore that a single-bladed rotor will be the most efficient.
I assume that this theoretical advantage will also apply to the gyrocopter.

Dave

[Rotor-Head]

Rotor-Head;

On a helicopter, the fewer the blades, the more efficient the rotor. The implication is therefore that a single-bladed rotor will be the most efficient.
I assume that this theoretical advantage will also apply to the gyrocopter.

Dave
How does control input change? I took my remote controlled helicopter and disconnected one of the linkages from the swash plate to one of the the rotor grips so that one rotor was completely non-controllable. It just swung around lengthwise. I started it up and it flew fine using only one blade to generate life and control, while the dead blade just acted as a counter balance. The only difference I noticed is that I had to put about twice the movement in the stick to fly as it does with the 2 blades.

Ona 1 blade system, are the angles and deflections greater than in a standard helciopter?

[Sapientino]

What is the benifit, other than only buying one blade at a time rather than two?

theoretically the single blade is more efficient since it doesn't pass in the flow of the other one

[Sapientino]

Sapientino;
Do you know if Vladimiro Lidak had a problem with unbalanced drag? And if so, what he did to reduce it?


I don't know

[Sapientino]

Sapientino;

On a helicopter, the fewer the blades, the more efficient the rotor. The implication is therefore that a single-bladed rotor will be the most efficient.
I assume that this theoretical advantage will also apply to the gyrocopter.

Dave

infact we spoke about testing this concept on my autogyro

[Rotor Rooter]

Sapientino,

Thanks again.
______________

Rotor-Head,

On a 1 blade system, are the angles and deflections greater than in a standard helicopter?
As a guess only, I suspect that the angles will be close to those of a standard helicopter. The difference may be that the area of the single blade is increased and/or the rotor speed is increased.
__________________________

For anyone who is interested;

Last week a friend converged small electrical coaxial R/C to two single-bladed rotors. He said that the rotors were a lot heavier than the original 2-bladed rotor but the craft hovered beautifully.

Yesterday he tested a larger individual single-bladed rotor powered by a hand-drill. He said that it shook like crazy. He suspects that the problem is the in-plane drag of the rotor, particularly since the blade has built in twist. Today he is going to put a small vertical flat plate at the root of the CW-arm. He will then test the rotor with the flat plate being incrementally advanced outward toward the CW.

If this eliminates the vibration, he will then remove the flat plate and put an additional small arm on the rotor. This arm will be normal to the pitch axis and be azimuthually 90-degrees ahead of the blade. Then by incrementally sliding a small weight out this arm, he will see if 'weight' will provide the same vibration elimination as 'drag'.

Cheap and fun experiments in rotorcraft aerodynamics. :)

[C. Beaty]

Eugene Glurahef received patents on sliding counterweights 90º to the feathering axis while developing single blade tail rotors at Sikorsky.

That would have been in the 1950s or thereabouts.

[Victor Duarte]

a stupid remark :
a single blade rotor needs a counterweight for the lost blade....
a counter-drag for the lost drag....
additionnal stuff to compensate the lost blade...
why not to put another blade ????????

[MikeBoyette]

Chuck,
Tell them about flying your single bladed gyro in the 70's. That's a great story.

[C. Beaty]

It’s a long story, Mike, but I’ll try to repeat it as succinctly as I can.

I traded some stuff for a set of run out Hughes-269 rotorblades.

I made up a hub that incorporated a door hinge style joint at its center and used outboard drag hinges because the previous owner had tapered the root ends of two of the Hughes blades to make them resemble Bensen blades.

They flew beautifully after the usual amount of tinkering but I had the misfortune to be flying over the Gulf of Mexico about 100 yards offshore at Birdy’s altitude when a wire running my electric fuel pump came loose. Mustering dolphins, of course.

Needless to say, I did a water landing in about 12’ of water.

Someone was kind enough to give me a ride back to the airport where we picked up my trailer and a pair of ski ropes. Since I was already cold and wet, -it was around Christmas-, I swam out to the spot, dove down and tied a rope to the gyro.

Got the thing home, pulled the spark plugs on the engine, hosed everything down with fresh water and after a couple of days of drying, the trusty Mac lit right up.

I still had the urge to fly but had only one good rotorblade left. The obvious solution seemed to be a one-blade rotor.

I had seen pictures of the one-blade helicopter by one of the predecessor companies of MBB, so thought, with insufficient thought, why not?

My first attempt wouldn’t autorotate; I had been in too much of a hurry so had used a length of 1½” steel rod for a counterweight but it was too draggy.

Dragged everything back to the shop and made up a proper counterweight; a teardrop shape welded up from 1/8” steel sheet with enough lead poured in for balance.

The rotor autorotated just fine and was glass smooth as long as the stick wasn’t moved. Rapid stick movement caused a violent vertical hopping about like a dirt-tamping machine.

I think I might have gotten daylight under the wheels but decided then and there one-blade rotors weren’t my piece of cake.

My friend Gary, younger and far braver than I, wanted to have a go at it. Gary was just then growing new skin after a bout with an overhead stick.

I said; “Gary, be careful, move the stick very slowly or it will start hopping pretty violently.”

Well, Gary wasn’t careful; the machine started hopping and he stirred it around rapidly trying relocate the sweet spot and it hopped over with the rotor at full speed.

Gary lost more skin and it was back to the drawing board for me.

I suppose the MBB helicopter worked because of the use of a Hiller style servo rotor which can be adjusted for very slow rotor following. I have no idea how they compensated for the unbalanced torque.

[Rotor Rooter]

Chuck,Eugene Glurahef received patents on sliding counterweights 90º to the feathering axis while developing single blade tail rotors at Sikorsky.Thanks. Found patent # 2,475,318. It will be interesting to read.
______________________________________________

zeeoo,
why not to put another blade ????????You sound like Gillette. They are currently market-testing a 5-blade razor? ;)

Seriously, IF the single blade does offer an aerodynamic advantage and IF the 'dead' counterweight can be replaced by an essential item, and IF the problem of vibration can be overcome, then the single-bladed rotor may represent an efficient and economical rotorcraft?

It appears that electricity will be the dominant means of propulsion for future vehicles. Why not replace the counterweight with an electric motor? This provides the opportunity and the pleasure of spending little money developing a rotorcraft, while other others are spending billions of dollars, on your behalf, advancing electric vehicle technology and lowering its cost.

What about a gyrocopter having a single-bladed rotor c/w a small electric motor as the counterweight, and 2 or 3 alternators on the engine?

What about adding a large homemade capacitor and thereby shortening the takeoff and landing roll?

[Victor Duarte]

Dave,
in my mind, electric motors have a worse weight/hp ratio than thermic ones..am i wrong ?
so, producing electricity with a classical engine to feed an electric one may be less efficient, no ?
maybe with a fuel cell..
if i understand correctly, you think in using electricity to control the rotor..
do you think it is reliable enough for an amateur machine ?
can you imagine a "bug" in the control process... a potentiometer or a sensor goes mad and you have a wonderful eggmesher :D
i am certainly joking because i'm scared ... but i wouldn't trust something completely electrical, with no mechanical backup in an "amateur" or recreational machine..

and yes, we need more blades to shave !! the human, as the evolution suggests, becomes more and more hairy...

[C. Beaty]

Dave, how do you locate patent numbers so quickly?

I’ve had a number of patents issued in my name but can’t find them without knowing the patent number in advance.

The US Patent Office web site completely baffles me. I didn’t think searches by subject matter were possible for patents issued before 1980.

[Rotor Rooter]

Zeeoo,

Power to weight ratio;
It has been mentioned that electric motors producing up to 2 hp per pound are being manufactured. Currently, they are probably expensive, but look at what happened to the price of cars when Henry Ford got involved, and look at what happened to the price of electronic devices when Gates and Intel got involved.

Safety;
Automobile users will never accept electrical vehicles that have lower standard of safety than current vehicles have, and the automobile will continue to be a primary source of components for rotorcraft hobbyists.

Some people have probably already flown with electric prerotors. Few, if any, have flown an all electric rotorcraft. What we are talking about is the pleasures and dreams of some rotorcraft hobbyists as they slowly and proudly develop a rotorcraft that morphs from one to the other. Flying initially by remote control or ground based generator, or with very short fly times but the improvements and pride of their craft will continue.

[Rotor Rooter]

Chuck,

I cheated. Two of Gluhareff's patents were referenced on Vladimiro Lidak's patent. :o

[Victor Duarte]

Dave,
ok , i m with you when you talk about the evolution of elctric motors... i'm just scared that they will be exactly like gas engines today : for cars.
that means that aviation will have to dig and dig again to find acceptable motors...unless rotax produces the future 912 E (for electric) at 25,000$
i'm ok, electric motors can be powerful and lighweight BUTthe weight needed to produce or keep power is HUGE ...almost like NiMH betteries W/ a brushless motor.. the problem is the potential energy/weight that is, for now, higher in gasoline or kero....maybe with a fuell cell it will be better..a smal atomic turbine could be even better..
seriously, when you think in such a rotor for a gyro, do you mean the electric motor could control the cyclic ?

[MikeBoyette]

Dave,
I have one of those new Gillette 5 blade razors, It works great.

[Rotor Rooter]

zeeoo,when you think in such a rotor for a gyro, do you mean the electric motor could control the cyclic? Maybe yes, maybe no. The details are up to the individual.

Currently rotorcraft is a mature industry. Those who seek to build a craft with a future must think in terms of future technology. They will have to think in terms of; no tail rotor, composite construction, plus electric power and controls.

We know that it is coming. Why fight the tide when you can ride the wave.

[Victor Duarte]

Dave,
i agree, thinking about a future design must be done with a visionnary sight.
there are 2 goals possible in design : shape the future of make the present more available..both are valuable paths..
i think the amateur market needs the second one...
but ,yes, it's coming, no...it's here : http://world.honda.com/news/2004/2040824_03.html
it's just a matter of some years to find this in every backyard.

Just don't forget what happened to most of the "visionaires"...remember good year...tucker... the famous custer's channel wings..and all the others.. not to mention la cierva or kaman...
they were beaten , not by lack of genius...but by stupidity and, overall , the rules of the industrial lobby..

[Ga6riel]

Electric motors to propel cars are an entirely worthwhile notion, not sure that translates well to aviation but it would be interesting to examine. The auto industry are terrified of this, they have a huge infrastructure investment in cast technology, much of which would be useless in an electricly motivated world. For this reason they have created the doubts that it would ever work, would be safe and reliable.

Prior to 1910, the Baker electric car could manage 120 miles on its Edison wet lead acid cells. In 1994 GM released the Impact electric car. It interesting to note that after 2 world wars, the space race and nuclear weapons the Impact could manage 90 miles range, 70 by the federal driving cycle. With that failure, GM can say that hey we tried, it just doesnt work. Its an idea whos time has come, and the sooner the better for we need it.

[dynacure]

Hydraulic driven tail rotor was tried on the second prototype Masquito heli
from Belgium. Now they are back to flexible shaft (as used in Wunderlich prerotator) driven tail rotor.

[Rotor Rooter]

Still on topic, if single-blade rotors offer the greatest efficiency, AND the vibration can be minimized.


http://www.acpropulsion.com/ACP_PDFs/ACP_SoLong_Solar_UAV_2005-06-05.pdf

http://www.acpropulsion.com/ACP_PDFs/ACP_SoLong_UAV_48hr_Flight_2005-06-05.pdf

[autorotate]

i may be in the wrong forum but if anyone is intrested in helping? im trying to develop a single wing airplane. haa honestly whats the point? take two blades remove one and try to substitute the perfect solotion "another blade" with some half ass counterweight solving only weight balance. what about arodynamic balance? to think it through and solve the shortcommings of a single blade whirling around you will have to ignorantly ignore the only true solotion another blade! also it was stated the blade wont strike the wake of the preceding blade . what about its own wake of greater amplitude? just for the heak of it i asked a friend whom knows nothing about hellies what he thought of a single blade. he said it sounded like reinventing the wheel. i thought vthat was great. by a show of hands who would buy a single bladed vibrocraft?

[Ga6riel]

autorotate
what about a 3 wing aircraft, does that fit your analogy as well?

[Rotor Rooter]

autorotate,

Actually, the counterweight was used in man's early flights. Three thousand years ago the Jews developed the counterweight for airmail delivery.

The first recorded use of it is when a person called David wanted to send a message to a person called Goliath. :D