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The future of the helicopter is electric.

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The future of the helicopter is electric.

Old 15th May 2004, 16:29
  #1 (permalink)  
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Location: Plymouth, UK
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Electric R22 anyone?

Just thinking out of the box...

If you take a Robinson R22 and remove the Lycoming engine, battery, alternator, drive shafts, clutch, belts, and both gearboxes, fuel tanks, how much does the unpowered fuselage weigh?

Now, if you replace all of those components with a pair of DC electric motors - a big one driving the main rotor and a little one in the tail - control equipment and as many Lithium-Ion batteries as you could carry up to the same weight, how much endurance would the resulting eco-friendly machine have?

I'm not an engineer, and I don't have ready access to the numbers, but I know that:

- Electric motors are a lot lighter than piston engines
- Electric motors are way more efficient
- Startup, shutdown and carb icing wouldn't be problems any more
- There would be a lot less moving parts, and reliability would be increased
- The end result would be eco-friendly and very cheap to run!


- Avgas has *much* higher energy density than, say, lithium-ion batteries
(this is probably the showstopper - figures, anyone?)
- Power and control systems would be critical to safe flight

If we get the weight & balance right, who's up for a ride in the result??

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Old 15th May 2004, 17:12
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Excellent idea, now if you also change the dynamic weights on just one of the blades to cause a slight imbalance...you have your very own cafe latte whisker
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Old 15th May 2004, 18:53
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I suggest that you have a look at the current electric radio controlled helicopters beginning to enter the market. They do not rely on Li-Cells but on a new type of cell that have a greatly improved power-density (the name escapes me). These machines have an endurance of about 7 minutes. WOW!

The all-electric-rotorcraft is not a new idea, the combination of modern gas turbines with shaft mounted integral high-speed electrical generators powering electrical motors via power-electronics has been bounced around by most of the big companies for years. Interestingly, the major motivation of this move would be an increase in system reliability rather than a performance/weight benefit. We are currently waiting for the technology to catch up with the concept, then i'm sure this stuff will start to make an appearance in the aircraft.

Hope this helps,
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Old 15th May 2004, 19:12
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Thumbs up Mr. Volta, what hath thou wrought

There is a man here in Canada that is working in conjunction with Siemans or one of their subsidiaries to use a motor that is powered by magnetic energy that is self contained and does not need an external electrical force. From what he told me this type of motor has already been developed now all they have to do is scale it up to power an aircraft or a helicopter.

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Old 15th May 2004, 19:14
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A contribution to the thread

Helicopter - Coaxial - Electric Motor Located between Rotors
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Old 16th May 2004, 10:31
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Now come on Lu... this sounds like the magic water-powered car one reads about on some forums. In order to do any useful work a motor has to get energy from somewhere.

Moreover I hoped you might be able to chip in with a bit of the engineering knowledge, such as the weights of components I mentioned. Any chance? Then we can know how much weight we've got to play with!

Cran: I'm not aiming to develop a hybrid, where electric motors are used purely for transmission. We have hybrid cars nowadays - to my mind they are horribly over-engineered.

I'm hoping someone with knowledge of battery systems can throw in some numbers as well. I've read that Li-ion batteries store about 120 watt/hours per kg, for starters...

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Old 16th May 2004, 15:48
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i would think that the weight of the batteries involved is the problem and the time spent "hot recharging" could be an issue aswell.
your 120w / kg battery would have the same performance as the engine in my car if it weighed 1000kg's
also im pretty sure 120watts per hour is 2 watts per minute if you want it to last for the hour. (120w for 1 minute)
i dont know if i am correct but im sure somone does
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Old 16th May 2004, 17:31
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Li-poly and Li-ion batteries are great but they are very finicky. If you charge them wrong, too hot, too quickly, they have a tendency to catch fire very quickly. Also they would get extremely hot pumping out the juice required for your two electric motors.
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Old 16th May 2004, 18:33
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Thumbs up


If, in the distant future, this were to be useful - you would need to do it via fuel cell technology. The problem, within the limits of TODAY'S capabilities, is that you simply can't carry enough H2. I've read some interesting research on microfibers that allow you to trap more H2 molecules, hence increasing the amount of H2 you can carry in one cylinder. Still, I think it will be 20-30 years before something efficient is put together.
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Old 16th May 2004, 20:56
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Thumbs up A fly in the ointment. Or is tha an oint in the flyment?

If you have ever cranked up a Bell helicopter with the battery in the nose you will have noted the spinning of the magnetic compass. Is it possible that you will have the same effect but on a continuous basis if you power the driveline with DC motors.

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Old 16th May 2004, 23:03
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Imagine the helo landing next to the bowser and asking for 37 Coulombs of electrons, please.

The problem with electric motors is how to store the electrons. We all know that only round electrons can roll through wires, but they are not easily stacked up.

Flat electrons are stacked into batteries, but need a convertor to change their shape into round electrons to get into the wires. So, will this helicopter run on round or flat?

And what if, by accident, some of the coloured electrons (which normally run around in neon signs) get into the engine? Will it leave coloured trails in the sky? Might be handy for airshows, though...
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Old 16th May 2004, 23:45
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A.C., they would surely have to be round ones, otherwise you would get an interrupt in the rotation of the blades as the corners of the flat ones got caught in the power cable.

It may be possible to use tape wire (like you see down the side of a building as a lightning conductor) to avoid the need for a converter to change them.

I believe that it is possible to de-colour them. There is a chap here who makes good money taking the colour out of the diesel he buys in China, so the same principle could be applied.

You see, all it needs is Good Science, and Rotorheads can solve all these technical problems.
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Old 17th May 2004, 03:41
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You guys are barking up the wrong tree.
Obviously the batteries are the sticking point; too heavy, too dangerous, so get rid of 'em - use a mains outlet and a very, very long extension cord.
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Old 17th May 2004, 06:14
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You've obviously been in contact with the fellow in Vancouver, who has made some startling breakthroughs in his development of oval electrons? Could be the interface that you are looking for.

Not sure how they affect the colouration aspect, though. Could be they will be up into the ultra violet spectrum, and only cause distress to pets, rather than the public.
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Old 17th May 2004, 11:01
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in the motoring supplement of yesterday's sunday times there is an article regarding an attempt at the electric-land speed record. using a new type of battery [radial cell??] they hope to break the 300mph limit, but the batteries are only good for 7 minutes or so.
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Old 17th May 2004, 13:10
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Everything that's old is new again...

Just to let you know, that this has been done.

Back in the 80's Orlando Helicopters (the group that created the WhisperJet and Hummingbird kit) successfully flew a Sikorsky S-52 (HO5S-1) on battery power. I believe they were using lead-acid batteries and a torpedo motor. I'm sure it was a pretty short flight, but proved (?) the concept.

BTW, Do you really think they're keeping it up for seven minutes, or does it just seem like seven minutes?

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Old 17th May 2004, 13:57
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nasa have actualy just developed new wire cable to convert the flat electrons into round ones, by narrowing the cable down (like a funnel) it squashes them into a ball which greatly increases the rate at which work can be done. the angle of narrowing (commonly called phase angle) and the use of fully ridgid insulation that goes hard after its heated, seems to be the winning factor.

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Old 17th May 2004, 14:21
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Vorticey, I guess nasa is the Northern Australian Science Academy.

I understand that their research into the conductivity of large piles of empty tinnies, when wired to the mains to stop urinators has received high acclaim, as far afield as Tennant Creek.
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Old 17th May 2004, 20:02
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Smile More

An all-plastic battery
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Old 18th May 2004, 23:40
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everyone that has done formal training knows that the electron's name is phil and they even made a film about him. what he does is throw his body forward down the line and his feet follow. this is different to the french belief in holes and it moves in the opp direction.Colouris just the shirt that phil is wearing at the time.
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