Building of a manned copter with a gasoline engine.

We are building a manned copter with a gasoline engine and propellers with variable pitch.

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In order not to repeat itself - very detailed information is available on our website - https://flying-bike2018.com/home/

A small video report - on this video!

https://www.youtube.com/watch?v=LscfTQb7P3I

Before asking questions or commenting - a big request - read the description of the project on the site. I tried VERY MORE to describe my arguments.

As the construction of the Copter progresses, I will publish new information.

I was wondering why nobody has gone for four ducted fans, which would give greater thrust and be just as controllable.

Like this?

https://en.wikipedia.org/wiki/Moller_M400_Skycar

Um, no.

Something that actually works!

In the design of this thread, a LOT of complexity could be removed by simply using ducted fans instead of four sets of variable pitched props.

I also wonder why he doesn't keep the electric motors and simply have the gas engine run a generator, if he's going off the shelf as much as possible.

But HUGE kudoes for not calling it a "manned drone." I really, really hate that.

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Originally Posted by Frank Giger

Um, no.

Something that actually works!

In the design of this thread, a LOT of complexity could be removed by simply using ducted fans instead of four sets of variable pitched props.

I also wonder why he doesn't keep the electric motors and simply have the gas engine run a generator, if he's going off the shelf as much as possible.

But HUGE kudoes for not calling it a "manned drone." I really, really hate that.

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As I recall, numerous experiments in wind tunnels have shown that propellers in annular nozzles have a higher efficiency only in the case of very precise manufacturing, with a minimum annular gap.
But the increase in thrust efficiency is "eaten up" by the greater weight of the ring nozzle and the increased air resistance.
Therefore, despite the seemingly high efficiency, in practice no one applies.
And besides, the mechanism of turning the propeller with a ring nozzle is of great weight and complexity.
The design of the variable pitch propeller, which has been used for many decades in hundreds of thousands of aircraft and helicopters - is simpler and more efficient.

As for the gasoline engine with the generator - look at the weight of the generator. The power of at least 100 kW.
And the efficiency of the "bundle" gasoline engine - generator - electric motor - is also low.
It's good for ships. It was tried during World War II by Porsche on the "Tiger" - Panzerkampfwagen VI "Tiger P" VK4501 (P).
But for airplanes - it is still difficult and uneconomical.

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Originally Posted by Frank Giger

Um, no.

Something that actually works!

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That was kind of my point. So far I don't think anyone has made it work.

Well it worked for Moller, he managed to entice a lot of people to give him money for something that never got out of ground effect (and even not overly stable there).

If you look at the designs of Moller from the point of view of a normal aviation engineer - he could not do anything!

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In 200x - a design with 8 motors, stabilization which is done by changing the engine speed - complete nonsense! The inertia of the gasoline engine is too big. A person's reaction is too slow for such a small device.

In the M200M - the control of shutter-blinds ... Complete nonsense. This scheme operates on an hovercraft. But not on an aircraft.

The rest of his designs are beautiful, like toys. But from the point of view of the fact that they must fly - complete nonsense!
There is no practical sense.

I never have figured out whether Moller would be more at home having dinner with Dunning & Krueger, or Ponzi.

That said -- the effort described in this thread could work, or might not. Time will tell. Please keep us posted, Thor.

His idea certainly has a lot of merit and promise.

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Originally Posted by Frank Giger

His idea certainly has a lot of merit and promise.

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Disagree. It combines the disadvantages of conventional helicopters with the disadvantages of multicopters, with few of the advantages of either.

Conventional helicopter design extracts rough, unwieldy horsepower from a reciprocating engine and delivers it to one or at most two rotors using mechanisms such as shafts, gears, and belts. The mass penalty of such a system drives the convergence towards designs with short drive trains and large rotor disks, and with relatively complex control systems involving independent adjustment of the pitch of each rotor blade.

The current trend towards multicopters is driven by increasing availability of powerful electric motors and batteries, and the availability of computer-driven controls for them. With an electric multicopter, you can have fixed-pitch rotors on each of four or more motors. You control attitude by independently adjusting the amount of power delivered to each motor. The inefficiency of the smaller rotor disks is compensated by the lighter weight of electrical power distribution and by the elimination of rotor pitch controls. Having all the motors and rotors identical yields economies of scale in production and support. System redundancy is achieved by designing so that flight is possible even with the failure of one or more motors or rotors.

--Bob K.

Concur.

The design he's putting forward is pretty dang complex in execution. Grab four electric car motors and find a way to generate and step up the voltage required for them.

I also think that he's giving himself some CG problems by starting with a tandem aircraft from the start. Might as well ditch the passenger, as this thing will be loud enough to be unable to hear their screams.

However, the notion of having a gasoline power plant (and I think he's overstating the weight of the generators needed) gets over the hurdle of limited battery capacity.

On redundancy, forget it. If one of the rotors goes out, that's it. Period. You're done for the day and are going to land RIGHT NOW. There isn't any auto rotation or glide.

One of the things not mentioned is just what the mission parameters of the aircraft are, or the performance goals.

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Originally Posted by Frank Giger

On redundancy, forget it. If one of the rotors goes out, that's it. Period. You're done for the day and are going to land RIGHT NOW. There isn't any auto rotation or glide.

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Personally, I think you have to be using a pretty broad definition of "land". I can see no way that craft could remain upright or controllable with less than all four rotors running.

Even if there's a power combiner of some sort so that one engine can drive all four rotors, the loss of a gearbox or drive shaft looks to my non-aeronautical engineer eyes like it would cause an immediate and catastrophic loss of control, followed shortly by an impact (or "destructive landing").

Maybe I'm wrong, though. It would certainly be easy enough to prove or disprove. How do electric powered quad-copters handle the failure of one rotor?

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Originally Posted by DaleB

...How do electric powered quad-copters handle the failure of one rotor?

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As I understand it, with a quad you can only retain control if two rotors are enough to support the mass and you can apply occasional upward thrust with the rotor opposite the failed one--which is to say, it probably doesn't really work. I think I've heard that, from a practical perspective, it takes six to survive the loss of any one motor, and eight to survive the loss of any two.

--Bob K.

And we have to be very, very careful when trying to translate performance of small RC planes to full sized ones. The thrust to weight ratios are much higher in RC aircraft.

There's a great video of an RC airplane that loses a wing and, thanks to a lot of thrust, manages to be brought back to earth with no further damage by hanging from the prop. Some wag then used some computer magic to make it look like it was an actual aircraft landing at the end, which fools a lot of non-airplane folks.

"...And we have to be very, very careful when trying to translate performance of small RC planes to full sized ones..."

I absolutely agree!
And this is especially true of the "scaling" of the Copters.
With the increase, absolutely other problems appear, which are not present on a small scale.
I take this into account.
That's why I'm forced to use variable pitch propellers and a gasoline engine.
I wrote about this in detail on my website!

[QUOTE=Ihor Nastashchuk;68841]We are building a manned copter with a gasoline engine and propellers with variable pitch.

A couple of questions:
1. Are the pilot/pax sitting in the plane of the blades? What happens when one lets go?
2. Do the blade disks have sufficient mass to autorotate? What happens when a gearbox goes Tango-Uniform at a hundred feet?
3. Your VPP is not "used on hundreds of thousands of radio-controlled helicopter models" because it supplies collective pitch control only. You appear to rely on differential thrust from the four blade disks for your "cyclic". Is this the only engineering misrepresentation/ignorance you are displaying?

If you're lucky, you'll attract only half the lawsuits that Moller did.

Ihor, if they lose power, airplanes can glide under control and helicopters can autorotate to a probably survivable landing. But if your quadcopter lost power to one or more propellers, it would flip and accelerate to the ground, tangling up the parachute if it could even be deployed. I think you ought to redesign it to survive the failure of any one component.

"...misrepresentation/ignorance you are displaying..."

I advise you to refrain from rudeness, but first learn to read carefully!

1. It is evident in the figures and in the photo that the pilot sits above the plane of rotation of the propellers.
2. I already answered this question - propellers with a high load on the area are NOT autorotated!
3. I already answered and this question. For VERY DARK AND LAZY - I repeat - will be the same as with a helicopter, which broke the reducer!
Only in difference from the helicopter (I repeatedly REPEAT) - I have a system of parachute rescue.
Yes, instead of changing the cyclic pitch on one propeller, like a helicopter, I applied a change in the overall pitch on the four propellers.
Why is this ignorance?

"...If you're lucky, you'll attract only half the lawsuits that Moller did..."

With my luck, I'll figure it out myself, without such advisers!

"...if they lose power, airplanes can glide under control and helicopters can autorotate..."

You're right. But only partially.

The helicopter will be autorotated if the engine has decayed and the propeller does not get stuck. If it sticks - no autorotation.
If the blade breaks - the same - there will be no autorotation - the helicopter will fall.

The plane will only plan if the engine has decayed. In the event of a breakdown of something else - a wing, a stabilizer, or even a flap or aileron - the airplane is likely to fall.

That is - the ability to plan or autorotate - depends on what a breakdown.

But it does not bother anyone - everyone flies.

So with my project. It depends on what will break.

100% guarantee can be given in this life only one - WE ALL DIE, sooner or later. All the rest is just a probability!
A parachute is a way to reduce this probability!

Besides - why should it break?
Look at it.

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In comparison with these propellers, mine are just a coffee grinder!
But on helicopters this heap has been flying for decades!

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Originally Posted by Ihor Nastashchuk

3. I already answered and this question. For VERY DARK AND LAZY - I repeat - will be the same as with a helicopter, which broke the reducer!
Only in difference from the helicopter (I repeatedly REPEAT) - I have a system of parachute rescue.

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I don't think there would be time to deploy a parachute system if one (or more) rotors fail. The high CG and un-balanced vertical thrust will flip that thing over in a heartbeat. Just my opinion. You could use accelerometers to determine when to automatically deploy -- a risky approach, but in any case I doubt a 'chute would do a lot of good outside of one or two specific failure modes.

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Originally Posted by Ihor Nastashchuk

The helicopter will be autorotated if the engine has decayed and the propeller does not get stuck. If it sticks - no autorotation.
If the blade breaks - the same - there will be no autorotation - the helicopter will fall.

The plane will only plan if the engine has decayed. In the event of a breakdown of something else - a wing, a stabilizer, or even a flap or aileron - the airplane is likely to fall.

That is - the ability to plan or autorotate - depends on what a breakdown.

But it does not bother anyone - everyone flies.

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True, but that's because the failure modes you describe represent a tiny, tiny fraction of the overall total incidents. In-flight breakup, whether fixed wing or rotary, is an exceedingly rare occurrence. Engine stoppage and gearbox failure is certainly not. You cannot simply hope it never breaks because of your superior design, which I think history has shown will be nowhere near as failure-free as you imagine it might be. You really have to assume that anything that moves will break with some degree of frequency. You'll never be wrong. So... what happens, exactly, when your pilot is flying along at max thrust and the left front gearbox fails? Prop stopped or prop free-wheeling, the result is the same. In a matter of half a second or so your pilot (and his hapless passenger) will find themselves in a rapidly rotating free-fall. No control at all, and deploying a parachute will just provide shroud to contain the body parts after impact.

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Originally Posted by Ihor Nastashchuk

Besides - why should it break?
In comparison with these propellers, mine are just a coffee grinder!
But on helicopters this heap has been flying for decades!

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You just answered your own question, I think. I don't think your system is designed and built to the same standards as Kamov. And it's not the prop hubs I would worry about, it's all the power transmission parts.

Just do everyone a favor. When it's time for flight testing, load that sucker with sandbags instead of live bodies, and fly by remote control for the first hundred hours or so. It may be very enlightening.

The Curtis Wright Quadrotor crashed when a shaft broke, fortunately in hover. The outcome would be disaster at 50 feet.
From my mini drone, I notice extreme vortex interactions that occur at near ground level. Much worse than a single rotor.
The V-22 had some Vortex Ring State crashes. Almost all VTOL crashes are fatal.
The power shafting might get extreme load variation. Would need expert design of shafting to understand torsional vibration.

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Originally Posted by DaleB

I don't think there would be time to deploy a parachute system if one (or more) rotors fail. The high CG and un-balanced vertical thrust will flip that thing over in a heartbeat. Just my opinion. You could use accelerometers to determine when to automatically deploy -- a risky approach, but in any case I doubt a 'chute would do a lot of good outside of one or two specific failure modes.

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I think an automated deployment system would work. Continuously monitor rates and power levels, and if a set of thresholds are exceeded, kill all power and fire the chute.

Down low is going to be a bad part of the envelope, though. A conventional (Cirrus-like) ballistic chute wouldn't open fast enough to inflate until one gets several hundred feet high. Depending on the type of failure, in the interim, the aircraft may well get to a high deck angle.

This basically needs the capability of a zero-zero ejection seat, which the Russian industries have done pretty well at. Explosive opening of the chute, rockets stabilize the body. It is going to run the price up quite a bit. May be some pushback from civil authorities regarding operating in urban areas...all the rockets and explosions might not be too good for the other cars in the Value Village parking lot.

Finally, this system is going to require a lot of testing. As Dale says, you can operate it remotely easily enough, but I suspect you'll trash several very expensive vehicles by the time you get it right.

Ron Wanttaja

"...I don't think there would be time to deploy a parachute system if one (or more) rotors fail..."

You are absolutely right! But my design is arranged so that the most likely failure is the loss of traction. The variant of asymmetric thrust is more likely when the blade is detached.
But I will try to prevent this from happening.
In the end, it's not an incredible task. Did someone often hear about the broken blade from the aircraft propeller?
My propeller design is closer to the aircraft than to the helicopter. I do not have those hinges and dampers that are in the helicopter. My screw is practically an ordinary airplane. Only the step change drive is not through the hollow shaft, but outside. Like helicopter steering propeller.
Reliable enough thing. Breakdowns are more common with long shafts or strikes about something.


"...and the left front gearbox fails..."

I have never described the design of the transmission.
Therefore, I simply say (since the industrial design is not yet patented) - such a breakdown, which will lead to asymmetric draft - is almost unreal.

"...load that sucker with sandbags instead of live bodies, and fly by remote control..."

Of course! That's exactly what I'm going to do! :-) Suicidal tendencies are not in my nature! I love life! And I hope this is mutual!

"...built to the same standards as Kamov..."

Well ... Kamov started with this.

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Do you see a big difference? :-)

"...As Dale says, you can operate it remotely easily enough, but I suspect you'll trash several very expensive vehicles by the time you get it right..."

I would not like that! With financing - and so it is not easy. That's why - I went to IndieGoGo!

But seriously - I understand that there will be more problems and questions. Much will still appear during setup and setup. Then - during the tests.
But not trying - you do not know! Is not it?
In the end, the Wright brothers, Sikorski and others were in much worse conditions. We have experience of them and our new technologies.

I understand that the greatest danger is asymmetric thrust. Therefore, in the design, I try to foresee this. It turned out or not - I can find out only by trying!


Starting the campaign on IndieGoGo, I hoped that it would be interesting not only to me. But judging by the result on the Indies - everyone wants to give me only advice. And rudeness!
But the support of the project - at least out of curiosity - "what will it do?" - NO!
It's a pity!

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Originally Posted by Ihor Nastashchuk

Therefore, I simply say (since the industrial design is not yet patented) - such a breakdown, which will lead to asymmetric draft - is almost unreal.

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OK... that just leaves me at a loss for words. "It can't break". Good luck with that, let us know how it turns out.

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Originally Posted by Ihor Nastashchuk

In the end, it's not an incredible task. Did someone often hear about the broken blade from the aircraft propeller?

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The majority of aircraft propellers are solid pieces of metal or wood.

Most of the remainder have a half-century or more of engineering history and operational experience.

Even so, you occasionally hear of propellers breaking or shedding blades...even the ones that are solid wood or metal. It's a major event in a fixed-wing aircraft, but not necessarily catastrophic. The key is to shut down the engine quickly enough so that the vibration doesn't cause the engine to shake right off the airframe and ruin the balance of the airplane. If you can accomplish that, it's just a "normal" emergency landing. I knew a guy who added cables around his engine to hold it approximately in place if the prop broke.

Of course, you rarely hear of helicopter rotors breaking...but, again, it does happen.

With your design, loss of a blade will not only result in severe vibration but immediate, abrupt attitude excursions. As pilots, we would like to know what is being done to make such occurrences survivable.

Ron Wanttaja

I am constantly reminded of breakdowns.

Let's figure it out.

With the breakdown, which causes a drop in traction on all propellers - it is understandable. Decrease and landing or parachute.

The failure causing asymmetric thrust can be of two types:

- Drive failure to some propeller or propeller pitch changing mechanism.
In this case, the reaction speed and the accuracy of modern electronics should be sufficient to maintain a stable position in the air.
At least - such videos about flights of copters with variable pitch propellers give an opportunity to hope for it.
The reaction time of the small copter is much smaller than that of the large copter. Nevertheless - the electronics are doing fine. (In the video - a small copter with variable pitch propellers).


https://www.youtube.com/watch?v=Scj8_XEEL1A&t

- Breakage of the blade and strong vibration from imbalance. In this case, the pilot of my copter will remain the same as the pilot of the helicopter, which broke the blade - to pray!
But the pilot of my copter even has a small chance - a parachute. The helicopter pilot does not have this.

But the helicopters are flying! And helicopters fly a lot of people!

You could get some comfort from a very large number of small props.
Say 60 props. And have 6 separate autopilot controllers that are controlling 10 motors each.
That would be super redundant. Sort of like the guy at Oshkosh that flew below 60 helium weather balloons.

But 60 props driven by one engine isn't redundant. And heavy.

Parachutes are fine for one at altitude, but this thing just begs to be flown low and slow.

I'd rather have a light roll bar and a four point harness, and if I had to chose between that or a parachute, still take the roll bar.

I guess my hesitation with the whole variable pitch prop approach is that it adds a huge amount of cost to the end product.