Dynamics Concept - Modification to Intermeshing Rotors
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Dynamics Concept - Modification to Intermeshing Rotors
The following web page describes a potential means of eliminating four concerns with the intermeshing configuration. The major advantage is that the blade to ground clearance can now be equal to or greater than that of a comparable single-rotor craft.
Rotor Concept - Intermeshing Rotors w/ Anhedral
Criticism appreciated.
This invention is posted so that it is in the public domain and cannot be patented by one to the detriment of others.
Dave J
Rotor Concept - Intermeshing Rotors w/ Anhedral
Criticism appreciated.
This invention is posted so that it is in the public domain and cannot be patented by one to the detriment of others.
Dave J
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Dynamics Concept - Modification to Intermeshing Rotors
Dave J. As you are posting details of your invention, could I ask if this is because the cost of a patent in your country is prohibitive.
Bug,
It's not the cost of obtaining patents that is the problem - although for a small company/individual the cost can be a problem. The real issue is defending them. All a patent does is give you the right to sue if somebody copies your invention...so what happens if a Multi-national corporation decides it likes joe-public's patent and is going to use it? Can joe-public really expect to take on a huge corporation in the courts? (Financially speaking.) They would just bleed you dry, wait for you to curl up and die and then carry on regardless.
My opinion is that you should just avoid letting them know how you did it! Keep you hard-earned knowledge to yourself! Or do it Dave's way and make it unpatentable!
Hope this helps
CRAN
It's not the cost of obtaining patents that is the problem - although for a small company/individual the cost can be a problem. The real issue is defending them. All a patent does is give you the right to sue if somebody copies your invention...so what happens if a Multi-national corporation decides it likes joe-public's patent and is going to use it? Can joe-public really expect to take on a huge corporation in the courts? (Financially speaking.) They would just bleed you dry, wait for you to curl up and die and then carry on regardless.
My opinion is that you should just avoid letting them know how you did it! Keep you hard-earned knowledge to yourself! Or do it Dave's way and make it unpatentable!
Hope this helps
CRAN
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Hi Cran, bug, dave
Cran you are very right.
Bug : if you want to deposit a patend or an idea, just send it under a stamped envelope to a lawyer and ask him to keep it.
I france we have a good and cheap system called "enveloppe Soleau" : for about 100 euros (don't know exactly) you can send an invention in this famous envelope with only a description of the content of your invention. so, if someone wants to know what's in, he must contact you and buy it.
I learnt that some companies don't hesitate to buy a serie of envelopes, expecting to find a pearl.. sometimes it works, but it can be bluff
, i invented the machine that turns BS into gold..interested ? .
regards.
Cran you are very right.
Bug : if you want to deposit a patend or an idea, just send it under a stamped envelope to a lawyer and ask him to keep it.
I france we have a good and cheap system called "enveloppe Soleau" : for about 100 euros (don't know exactly) you can send an invention in this famous envelope with only a description of the content of your invention. so, if someone wants to know what's in, he must contact you and buy it.
I learnt that some companies don't hesitate to buy a serie of envelopes, expecting to find a pearl.. sometimes it works, but it can be bluff
, i invented the machine that turns BS into gold..interested ? .regards.
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bugdevheli,
CRAN has presented a very strong reason. The following is another one.
I believe that the problem in 'Rotorland' is not the competition from other manufacturers. It is the lack of consumers. Worldwide, there is only 1 civilian helicopter per 500,000 people. The 'potential' market is certainly not saturated.
If cooperative conceptualization and technical support results in a new and better generation of rotorcraft, there should be opportunities for many. Then, the manufacturers may wish to protect their lower level details.
Personally, I believe that the lateral twin-rotor configurations stalled at the end of WW II. Other people may have different visions.
Dave J
CRAN has presented a very strong reason. The following is another one.
I believe that the problem in 'Rotorland' is not the competition from other manufacturers. It is the lack of consumers. Worldwide, there is only 1 civilian helicopter per 500,000 people. The 'potential' market is certainly not saturated.
If cooperative conceptualization and technical support results in a new and better generation of rotorcraft, there should be opportunities for many. Then, the manufacturers may wish to protect their lower level details.
Personally, I believe that the lateral twin-rotor configurations stalled at the end of WW II. Other people may have different visions.
Dave J
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Cran is quite right about patents. Look at the Wright brothers, they wasted many years over the wing twist patent while others such as Curtis simply invented ailerons. Trying to maintain a monopoly, and a patent is simply a government sanctioned monopoly, is a waste of time and money in my opinion.
I think Dave's open sharing has merit. The complex nature of his goal benefits frome others that have constructive criticism.
Dave, I have a primal distrust of the intermeshing configuration and so it is hard for me to look at the advantages. One thing I was thinking about this week is how dangerous a helo really is in a hover at 50ft. I came to the realization that the primary problem is the downwash. A hovering helo is in self induced downdraft, so when the engine quits there is really nothing that can be done other than fall like a rock. The solution might be to direct the downwash at an angle other than vertical down.
Your intermesher might do that, and that would be an advantage.
Does the Kmax logging helo have any advantage in a low level power loss because of the intermesh?
Slowrotor
I think Dave's open sharing has merit. The complex nature of his goal benefits frome others that have constructive criticism.
Dave, I have a primal distrust of the intermeshing configuration and so it is hard for me to look at the advantages. One thing I was thinking about this week is how dangerous a helo really is in a hover at 50ft. I came to the realization that the primary problem is the downwash. A hovering helo is in self induced downdraft, so when the engine quits there is really nothing that can be done other than fall like a rock. The solution might be to direct the downwash at an angle other than vertical down.
Your intermesher might do that, and that would be an advantage.
Does the Kmax logging helo have any advantage in a low level power loss because of the intermesh?
Slowrotor
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re Patents:
The majority of helicopters, by far, are military craft. The US government states that it can take any patented invention, at any time, and do anything it wants with it.
slowrotor,
"I have a primal distrust of the intermeshing configuration."
The web page [Intermeshing Configuration - Concerns] covers every concern that I have come across regarding the safety, reliability and performance of the intermeshing configuration. Following each concern, a response is given. I have attempted to keep this information as factual as is possible, since the inclusion of hype would serve no purpose.
Perhaps some of this information may allay your concerns. Then again it may enhance them.
"...how dangerous a helo really is in a hover at 50ft. I came to the realization that the primary problem is the downwash. A hovering helo is in self induced downdraft, so when the engine quits there is really nothing that can be done other than fall like a rock."
I assume that your primary concern is getting away from the downwash; by ether getting vertically through it or horizontally away from it. Perhaps, with very small rotorcraft, the disk loading, the resultant downwash velocity and the Vortex Ring State are too small to be a significant problem.
"Does the Kmax logging helo have any advantage in a low level power loss because of the intermesh?"
The K-Max might be able to quickly drop its load and thereby have a low disk loading. Just a guess. I do know that the Flettner intermeshing FL-282 was the first helicopter to enter then exit autorotation.
Dave
The majority of helicopters, by far, are military craft. The US government states that it can take any patented invention, at any time, and do anything it wants with it.
slowrotor,
"I have a primal distrust of the intermeshing configuration."
The web page [Intermeshing Configuration - Concerns] covers every concern that I have come across regarding the safety, reliability and performance of the intermeshing configuration. Following each concern, a response is given. I have attempted to keep this information as factual as is possible, since the inclusion of hype would serve no purpose.
Perhaps some of this information may allay your concerns. Then again it may enhance them.
"...how dangerous a helo really is in a hover at 50ft. I came to the realization that the primary problem is the downwash. A hovering helo is in self induced downdraft, so when the engine quits there is really nothing that can be done other than fall like a rock."
I assume that your primary concern is getting away from the downwash; by ether getting vertically through it or horizontally away from it. Perhaps, with very small rotorcraft, the disk loading, the resultant downwash velocity and the Vortex Ring State are too small to be a significant problem.
"Does the Kmax logging helo have any advantage in a low level power loss because of the intermesh?"
The K-Max might be able to quickly drop its load and thereby have a low disk loading. Just a guess. I do know that the Flettner intermeshing FL-282 was the first helicopter to enter then exit autorotation.
Dave
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Dave,
The intermesh may have one of the safest records and other advantages but it still probably would be a hard sell. If I was in the logging business I would consider the K-max, just dont think I would consider the configuration for sport. But I will do some study.
Cran has advised me that low disc loading increases the likely onset of vortex ring state.(normal descent rate is closer to vrs with low disc loading)
So my conclusion is low disc loading may help but in the case of a power loss at 50ft some other type of safety device would be needed, perhaps an airbag. Or muliple engines.
slowrotor
The intermesh may have one of the safest records and other advantages but it still probably would be a hard sell. If I was in the logging business I would consider the K-max, just dont think I would consider the configuration for sport. But I will do some study.
Cran has advised me that low disc loading increases the likely onset of vortex ring state.(normal descent rate is closer to vrs with low disc loading)
So my conclusion is low disc loading may help but in the case of a power loss at 50ft some other type of safety device would be needed, perhaps an airbag. Or muliple engines.
slowrotor
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slowrotor,
"Dave, I have a primal distrust of the intermeshing configuration and so it is hard for me to look at the advantages."
"The intermesh may have one of the safest records and other advantages but it still probably would be a hard sell."
Over the years, I came to the same conclusion as you, regarding the fault of the intermeshing configuration. The fault lies not with the dynamics and aerodynamics of the configuration. It lies with the perception of the configuration. A perception that originated 55 years ago when Kaman, for understandable reasons, took the configuration in the wrong direction, and Kellett, who was going in the right direction, lost a famous test pilot due to a non related fault. This ended any future consideration, evaluation, or development of the intermeshing configuration.
After thousand of hours of research, I am strongly convinced that the intermeshing and perhaps the interleaving are the best rotorcraft configurations. Or, as R. W. Prouty said "...... it [the intermeshing configuration] may have been ahead of its time and just the right configuration for some future helicopter requirement."
Dave
"Dave, I have a primal distrust of the intermeshing configuration and so it is hard for me to look at the advantages."
"The intermesh may have one of the safest records and other advantages but it still probably would be a hard sell."
Over the years, I came to the same conclusion as you, regarding the fault of the intermeshing configuration. The fault lies not with the dynamics and aerodynamics of the configuration. It lies with the perception of the configuration. A perception that originated 55 years ago when Kaman, for understandable reasons, took the configuration in the wrong direction, and Kellett, who was going in the right direction, lost a famous test pilot due to a non related fault. This ended any future consideration, evaluation, or development of the intermeshing configuration.
After thousand of hours of research, I am strongly convinced that the intermeshing and perhaps the interleaving are the best rotorcraft configurations. Or, as R. W. Prouty said "...... it [the intermeshing configuration] may have been ahead of its time and just the right configuration for some future helicopter requirement."
Dave
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configuration
Dave,
I wonder about your preference for intermesh. Why not coaxial?
The coaxial should not have blade strike possibility provided the separation is enough.
I would be concerned with gear mesh failure in a syncropter. Probably unlikely, but hard to get past.
For my designs I plan to use something other than gears, like belts, that would allow some slip.
I got a toy coaxial helo from Safeway. Paid one dollar! It was a return and required some tape repairs. Had it flying in 30 minutes. I was amazed because the thing would hover hands off. It has teetering coaxial rotors and is quite stable.
Does not go forward more than a crawl. No cyclic, has a rear rotor to tilt the disc and differential speed control of rotors for yaw turns.
The copter, its called Blade Runner, is usually $60 with radio complete at Safeway and othe places (just stocked at Safeway for Christmas). Made in Canada I think.
But the coaxial and intermesh both suffer from the fact that both rotors are operating with the same air , so the air must be accelerated to a higher degree than a singe rotor and therefor is less efficient in flight, not sure about autorotation.
But that little toy copter got me thinking, the coaxial shafting seemed pretty simple.
I wonder about your preference for intermesh. Why not coaxial?
The coaxial should not have blade strike possibility provided the separation is enough.
I would be concerned with gear mesh failure in a syncropter. Probably unlikely, but hard to get past.
For my designs I plan to use something other than gears, like belts, that would allow some slip.
I got a toy coaxial helo from Safeway. Paid one dollar! It was a return and required some tape repairs. Had it flying in 30 minutes. I was amazed because the thing would hover hands off. It has teetering coaxial rotors and is quite stable.
Does not go forward more than a crawl. No cyclic, has a rear rotor to tilt the disc and differential speed control of rotors for yaw turns.
The copter, its called Blade Runner, is usually $60 with radio complete at Safeway and othe places (just stocked at Safeway for Christmas). Made in Canada I think.
But the coaxial and intermesh both suffer from the fact that both rotors are operating with the same air , so the air must be accelerated to a higher degree than a singe rotor and therefor is less efficient in flight, not sure about autorotation.
But that little toy copter got me thinking, the coaxial shafting seemed pretty simple.
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synchro concept!?
Hi Dave;
Sorry to tell you that i don't see any invention, and at least any advantage...I need a 3D simulation to be convinced not to have a blade collision at the rear of the aircraft, as the blade's tips would be almost in the same plane...
I am not convinced neither, that the pitch-torque is a problem!...
As i know your commitment, i am gone a spend more time on your idea...
Would be great to have opinions of Kmax pilots...
Sorry to tell you that i don't see any invention, and at least any advantage...I need a 3D simulation to be convinced not to have a blade collision at the rear of the aircraft, as the blade's tips would be almost in the same plane...
I am not convinced neither, that the pitch-torque is a problem!...
As i know your commitment, i am gone a spend more time on your idea...
Would be great to have opinions of Kmax pilots...
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A sales pitch ????. 
slowrotor,
"I wonder about your preference for intermesh. Why not coaxial?"
The intermeshing has a number of advantages over the coaxial, particularly when considering future high-speed rotorcraft. A post in 1993 by the knowledgeable Paul Cantrell looked at the question from the opposite perspective: "I know the ABC is currently shelved, but I hope that it will started up again. I wonder whether intermeshing wouldn't work better - perhaps Sikorsky didn't want to have to deal with Kaman? I don't really know why they picked coaxial rather than intermeshing..."
"I would be concerned with gear mesh failure in a synchropter. "
This is an advantage. There are hundreds of potential failure points in a helicopter. The interconnecting final reduction is a short-coupled two gearset, which is intentionally over designed.
________________
quadrotor,
"... a blade collision ..., as the blade's tips would be almost in the same plane...'
This is one of a number of reasons for implementing Absolutely Rigid Rotors. The intermeshing feature is the only significant commonality between the well-known Kaman helicopters and the UniCopter project.
IMHO, Kellett was on the right track with his 3-blade rotors. He was seeking one million dollars to produce a rotor with greater rigidity. It appears that the death of Dave Driskill ended any chance of getting the funds and ended the company.
H-43 is a Kaman pilot, who has posted information about the Kaman helicopters on this forum. If interested, a search on [H-43] and [Rotorheads] should bring up his comments.
Dave
slowrotor,
"I wonder about your preference for intermesh. Why not coaxial?"
The intermeshing has a number of advantages over the coaxial, particularly when considering future high-speed rotorcraft. A post in 1993 by the knowledgeable Paul Cantrell looked at the question from the opposite perspective: "I know the ABC is currently shelved, but I hope that it will started up again. I wonder whether intermeshing wouldn't work better - perhaps Sikorsky didn't want to have to deal with Kaman? I don't really know why they picked coaxial rather than intermeshing..."
"I would be concerned with gear mesh failure in a synchropter. "
This is an advantage. There are hundreds of potential failure points in a helicopter. The interconnecting final reduction is a short-coupled two gearset, which is intentionally over designed.
________________
quadrotor,
"... a blade collision ..., as the blade's tips would be almost in the same plane...'
This is one of a number of reasons for implementing Absolutely Rigid Rotors. The intermeshing feature is the only significant commonality between the well-known Kaman helicopters and the UniCopter project.
IMHO, Kellett was on the right track with his 3-blade rotors. He was seeking one million dollars to produce a rotor with greater rigidity. It appears that the death of Dave Driskill ended any chance of getting the funds and ended the company.
H-43 is a Kaman pilot, who has posted information about the Kaman helicopters on this forum. If interested, a search on [H-43] and [Rotorheads] should bring up his comments.
Dave
Last edited by Dave_Jackson; 21st Feb 2005 at 20:35.
