Coaxial Helicopters

[Nobody]

According to wikipedia the Focke-Achgelis Fa 223 Drache (Dragon) could carry just over a ton (minus the weight of the pilot) in normal configuration. That quite a lot. Still its true helicopter weren't of much use until much later.

[Guinness]

Both German examples had intermeshing rotors, similar to Kaman designs in the US. Logi was curious about coaxial rotors, where one rotor is mounted atop the other on a common shaft.

For those who fear nverse helicoptor development in this period: I've reviewed historical examples, and there are some which were not successful. Having discussed this with Logi and his plans, I have no problem with him writing a story about an unsuccessful program now. If ever there came a question of technical feasibility, etc. the mods will rule when appropriate.

[Carthaginian]

According to wikipedia the Focke-Achgelis Fa 223 Drache (Dragon) could carry just over a ton (minus the weight of the pilot) in normal configuration. That quite a lot. Still its true helicopter weren't of much use until much later.

I think that if Nazi Germany was an N-verse nation, they would have been paying the equivalent of an extra $1 or $2 every half for a decade or two to both aviation and submarines.

[damocles]

Correct if I understand the type helo your are discussing. The rotors were angle offset, shared a common gearbox that produced opposite spin and were thus called  inter-meshing rotor not coaxial rotor, where one rotor sits inside another rotor; and the gearbox needs a set of orbital gears to produce the toque canceling opposite spin with one propeller screw sitting on top of the other-the solution which the clever Russians used in their superb Helix helos from 1955 on. That is not possible with 1920 or even 1930 tech. The metallurgy does not exist.      

Kaman managed to get the inter-mesh to work  with great difficulty by 1946. The German equivalent, the Flettners had just as many teething troubles, notably blade whip and strikes which were not solved (if you could call it solved, and actually was not possible before 1942.

A Sikorsky or a Focke Wulfe pattern might be ready by 1940 (swash plate and collective control). The only vertical lift machine possible with 1918 tech is an auto-gyro and that only when somebody has hinged blade rotor disks swash plates to solve rotor stall.

Historically that solution belongs by right to Iberia in the Nverse, or I would have started Fokker on that path around 1920. Then I would have asked for permission to use Juan Cieva's designs. or Paisecki's around 1930 when it is the earliest available.

D.            

[TexanCowboy]

Correct if I understand the type helo your are discussing. The rotors were angle offset, shared a common gearbox that produced opposite spin and were thus called  inter-meshing rotor not coaxial rotor, where one rotor sits inside another rotor; and the gearbox needs a set of orbital gears to produce the toque canceling opposite spin with one propeller screw sitting on top of the other-the solution which the clever Russians used in their superb Helix helos from 1955 on. That is not possible with 1920 or even 1930 tech. The metallurgy does not exist.      

D.            

The Austrians used that method in their PKZ-2, built in 1918. It was not capable of independent, non-tethered flight, but I bet it would have been if a few more years had been given to the project and money from a crumbling Austria could be obtained.

[Logi]

Logi was curious about coaxial rotors, where one rotor is mounted atop the other on a common shaft.

The rotors were angle offset, shared a common gearbox that produced opposite spin and were thus called  inter-meshing rotor not coaxial rotor, where one rotor sits inside another rotor; and the gearbox needs a set of orbital gears to produce the toque canceling opposite spin with one propeller screw sitting on top of the other-the solution which the clever Russians used in their superb Helix helos from 1955 on.

No Damocles, we were discussing Coaxial Rotors, not Inter-meshing Rotors.

[damocles]

Logi was curious about coaxial rotors, where one rotor is mounted atop the other on a common shaft.

The rotors were angle offset, shared a common gearbox that produced opposite spin and were thus called  inter-meshing rotor not coaxial rotor, where one rotor sits inside another rotor; and the gearbox needs a set of orbital gears to produce the toque canceling opposite spin with one propeller screw sitting on top of the other-the solution which the clever Russians used in their superb Helix helos from 1955 on.

No Damocles, we were discussing Coaxial Rotors, not Inter-meshing Rotors.

I know what you were discussing Logi. I responded specifically to Guinness answer about the Flettners. Frankly coax helos are irrelevant until 1955 anyway.

Not that I expect you not to TRY, but it isn't even possible. Nobody has even solved the constant speed single spinner propeller in the Nverse yet!

Correct if I understand the type helo you are discussing. The rotors were angle offset, shared a common gearbox that produced opposite spin and were thus called  inter-meshing rotor not coaxial rotor, where one rotor sits inside another rotor; and the gearbox needs a set of orbital gears to produce the toque canceling opposite spin with one propeller screw sitting on top of the other-the solution which the clever Russians used in their superb Helix helos from 1955 on. That is not possible with 1920 or even 1930 tech. The metallurgy does not exist.      

D.            

The Austrians used that method in their PKZ-2, built in 1918. It was not capable of independent, non-tethered flight, but I bet it would have been if a few more years had been given to the project and money from a crumbling Austria could be obtained.

How well did the gearbox for it do? I know that the French also had a tethered independent chain driven (three?) rotor machine in the hover under tether as early as 1915, but there was all kinds of stability control issues. Seriously, when you look at helicopters, you have to give Juan de Cieva his due. He is the go to guy, who solved rotor stall with the flap hinge blade, invented a prototype swash plate, worked out the rudiments of the collective, etc. That stuff took him 15 years of auto-gyro tinkering and he was almost ready to make the leap to a true helo when he died in 1936.

Flettner, Sikorsky, Paiasecki and a few others had to duplicate his work independently, after he died, from where he was in 1936, otherwise it would be the British and Cieva who would have the world's first helicopters in 1937-not the Germans in 1939.            

[Logi]

Arguing for argument's sake.

Frankly coax helos are irrelevant until 1955 anyway.

Perhaps, but I do recall Igor Sikorsky building a coaxial helicopter in 1909. (He proceeded to give up due to lack of good engines and good mechanics)

The Danish, Jen C. Ellehammer built a coaxial helicopter in 1914.

The Austrian, Stephan Petroczy built and flew a coaxial helicopter from 1917-20.

Raoul Pateras-Pescara built a quadruple stack coaxial helicopter in the early 1920s.

Nobody has even solved the constant speed single spinner propeller in the Nverse yet!

Correct me if I'm wrong, but the whole reason for Coaxial designs is that there isn't a big speed issue about the propeller in such a design.  Conventional designs with two separate propellers had to worry about speed because they had to match it so the torque is canceled completely.

If I am not mistaken, in a Coaxial design, the two are powered by the same engine and do not have to worry about speed since they go at the same speed to begin with.

Hence the advantage was, torque and speed considerations were taken off. The issue was getting a powerful enough engine to do anything useful for the craft.

[damocles]

Arguing for argument's sake.

Frankly coax helos are irrelevant until 1955 anyway.

Perhaps, but I do recall Igor Sikorsky building a coaxial helicopter in 1909. (He proceeded to give up due to lack of good engines and good mechanics)

The Danish, Jen C. Ellehammer built a coaxial helicopter in 1914.

The Austrian, Stephan Petroczy built and flew a coaxial helicopter from 1917-20.

Raoul Pateras-Pescara built a quadruple stack coaxial helicopter in the early 1920s.

Nobody has even solved the constant speed single spinner propeller in the Nverse yet!

Correct me if I'm wrong, but the whole reason for Coaxial designs is that there isn't a big speed issue about the propeller in such a design.  Conventional designs with two separate propellers had to worry about speed because they had to match it so the torque is canceled completely.

If I am not mistaken, in a Coaxial design, the two are powered by the same engine and do not have to worry about speed since they go at the same speed to begin with.

Hence the advantage was, torque and speed considerations were taken off. The issue was getting a powerful enough engine to do anything useful for the craft.

None of them worked or lasted in operation long enough to be viable as they pitched out of control or the gear boxes failed (shattered).

Like I said, you can try, but you aren't going to get the steels you need, nor are you going to get the flight control systems before you solve about 300 different issues between 1918 and 1938.

As for engine power? Nonsense. It was and always is vibration.

The machines shook themselves to bits.

[Guinness]

Gang: a good storyline about a failed technological effort is every bit as valuable as a good storyline about a successful one, in my opinion. The effort need not succeed to be of use, after all.

[TexanCowboy]

What about good storyline about an explosion?  ;D

[ctwaterman]

Nah there are no good storylines about expolsions.... now a gear box failing under stress leading to an explosion now that has plot suspence and intrigue.   Was it metal fatigue or did the dasterdly enemy agent substitute substandard materials.   

[TexanCowboy]

My explosion invovled secondary Frog explosions! (Which I felt was actually a fairly good writeup. Definatly would have provided experiance for what to do in Eilat some months later.)

[damocles]

Nah there are no good storyline about explosions.... now a gear box failing under stress leading to an explosion now that has plot suspense and intrigue.   Was it metal fatigue or did the dastardly enemy agent substitute substandard materials.  

The only way that would happen is if Logi, TC, Phoenix, and I could agree on a Dutch/MK/Romanian/RRC storyline where the RRC works on their contraption and the others contribute to the thing going "Romanian".

I have no problem blowing something Logi tries up, but you just can't do that without agreements by all involved.

Gang: a good storyline about a failed technological effort is every bit as valuable as a good storyline about a successful one, in my opinion. The effort need not succeed to be of use, after all.

KoN Crapfest is one example. If we do the helo thing it has to be an object ;lesson aa to why (at least for now) the work has no relevance to the way things go.  

What about good storyline about an explosion?  ;D

See above.

[TexanCowboy]

Why would I need to be invovled? Last time I checked, Romania was a neutral in this war, and the extent of it's ties are a non-agression treaty with the RRC.