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Old Jul 06, 2013, 04:03 PM
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I can't agree that any disturbance will cause "eventual crash landing". Because from my perspective it's true only for the case when angular momentum is pretty small.

My feeling is that I can rotate my gyroscopic disk so fast that it could resist any reasonable force that can appear in flight. I assume, we are talking about the wind here.

I am very sorry but I can't believe you until I try myself or unless I read convincing explanation somewhere.

All the tests I performed state that the more angular momentum the disk has the more resistance to the external forces it has.

As you may have noticed, I am not a physicist, so I don't understand high school explanations. Let me just keep doing my experiments, and maybe my results will be helpful for somebody else.
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Old Jul 06, 2013, 04:18 PM
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Your craft has many external forces that will act upon it,

1. Wind, even inside a building. Air has turbulence that will act upon your craft.

2. Turbulence created by your airframe while spinning.

3. Inertia of unequal distribution of airframe mass = Wobble.

4. Vibration and airflow from your propeller, You will have a twisting vortex of air surrounding your airframe that will impinge upon your airframe unequally.

I can name more, but these will tilt your craft off-axis to a crash landing.

Please keep trying, I'm only trying to keep a bit of realism attached to this thread.
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Old Jul 06, 2013, 08:24 PM
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Continuing from the previous post:

5: Your gyro-disk will work like a mini centrifugal air compressor, it will sling air off its surfaces tangentially to the propwash. The propwash will impinge upon the airflow from the gyro-disk, this will create a very turbulent region of airflow with completely unpredictable aerodynamic effects.

6. Your gyro-disk and propeller will have substantial Angular Velocity(AV), but each will have vast differences in AV and opposite spin directions, additionally they will not be equal distances from the center off mass of the craft.These vastly different forces at unequal distances from the center of mass will create rotation vector forces that will tilt your craft over into a crash. This is not how a coaxial Helicopter is configured, their rotor heads are of equal mass and diameter to counter the problems I just mention in item #6.

You have NO control surfaces to overcome these forces, this equals failure. Failure on many levels.
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Old Jul 06, 2013, 09:04 PM
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Road Runner Cartoon Physics

Quote:
Originally Posted by Zondt View Post
My answer is: In my world there are no pitch and roll axis rotations. These rotations do not happen unexpectedly. If I shift weight, then my aircraft does a translation (yaw axis moves parallel to itself). Zondt never tilts. If a wind blows, then the same translation .
Dmitry.
Your use Road Runner Cartoon Physics. What happened to critical thinking in this world?

We live in a highly technical world, yet the average citizen is virtually ignorant of basic classical physics.

In the last 10 years I have witness a huge slide downward in basic science skills. The average "Joe" on the street cannot possible contend with the complexities of our new "Digital Age". Joe has been stripped of a quality education, forced to work long hard hours for very low pay. The elite send their kids to college with Road Runner Cartoon Physics on their brains, completely crippling any chance of really learning how the world works. Joe can be excused since he has no choice, but I often read here on RCG fantasy thoughts on how they will build a VTOL of some such design, mainly because they saw it in a movie. Just read "The Cube" thread. A perfect example of someone trying to tell Mother Nature she is wrong. I see it time and time again, they think that putting the latest super controller board in will overcome basic aerodynamics and physics. On this thread we have just the opposite, no controls at all.

This thread appears to be the best example yet of just plain ignorance, and hubris.
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Old Jul 07, 2013, 12:42 AM
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Thanks for outlining these 6 points. I have never thought of some of them. The most interesting point is #6. I do not understand it yet, but I will study first and then return to you with questions if any. JFI: in my current version of craft the center of mass supposed to be in the center of the gyroscopic disk.

Very interesting thoughts about "Road Runner Cartoon Physics". Again, I have very weak knowledge in physics. I know almost nothing about aerodynamics. I studied maths (again badly) and IT. I have seen several video-lectures about gyroscopes on youtube and I made a lot of experiments with toy gyros.

The Cube thread is interesting, I first-time saw it today. I had the same aircraft behavior several years ago when I tried to use vector-thrust module from rc-kite without anyaerodynamic vanes. Just a motor and body. The same waving from side to side.

It will never fly without electronic gyroscopes. Or without mecanical flybar as was suggested, but in this case it will be a Turboplan.
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Old Jul 07, 2013, 01:16 AM
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We have very good demotivator in Russia about people (like myself) who do something difficult but stupid :-)
//Without any intent to insult anybody. Just a funny joke related to inventors as well.



First get results!
Then criticize!
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Old Jul 07, 2013, 10:42 AM
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It will never fly without electronic gyroscopes. Or without mecanical flybar as was suggested, but in this case it will be a Turboplan.
Now your starting to learn and make reasonable comments.

1. Find out what you don't know.

2. Then ask questions of yourself (i.e. do you have the basic understanding and educational background for this project) and ask others for assistance.

3. Read.

4. Build and crash.

5. repeat 1-4.

An electric Turboplane (German name Turboplan) is very workable assuming you pay very close attention to many small details that are hidden from obvious view.

I'm willing to help you if you're willing to listen.

If you decide to try a Turboplane I would recommend you start a new thread.

A Turboplane can fly without a gyro or flybar, but a standard cheap Mems gyro for Yaw is very helpful.

Kelly
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Old Jul 07, 2013, 12:22 PM
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Now your starting to learn and make reasonable comments.
As you wish, Mr.Kelly. But what I've said about electronic gyros was obvious for me 2 years ago. Thanks for above-mentioned 6 points, I'm still studying them.

Quote:
Originally Posted by corocopter View Post
If you decide to try a Turboplane I would recommend you start a new thread.
I will not decide building a Turboplan in the foreseen future of 2-3 years.

Quote:
Originally Posted by corocopter View Post
A Turboplane can fly without a gyro or flybar, but a standard cheap Mems gyro for Yaw is very helpful.
There's a misunderstanding about the flybar here. I told about flybar having weights-on-rods in mind, like it was done in one version of Turboplan. Here I did not mean helicopter flybar with rod that is connected with swashplate. Just something that has big angular momentum.
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Old Jul 07, 2013, 12:31 PM
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Quote:
Originally Posted by Zondt View Post
There's a misunderstanding about the flybar here. I told about flybar having weights-on-rods in mind, like it was done in one version of Turboplan. Here I did not mean helicopter flybar with rod that is connected with swashplate. Just something that has big angular momentum.
Yes that will work, you only need 2 weights, but they "Must Free Wheel", and be driven by propwash. If you use an electric motor you need an electronic feedback loop (circuit) which undermines the entire idea.

Good luck, your now on your own.
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Old Jan 07, 2014, 07:40 PM
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Wanted to refresh this thread.

I should admit first, that I can't post 10 seconds video, because I no more have ability to build actual models and crash them. Too expensive.

But I have access to MSC.ADAMS emulation tool. I have created very basic model of Zondt and showed how it behaves if a force is applied to it (wind mainly). There is also a demonstration how increased angular momentum decreases "falling to the side" effect.

Below there are two videos. It's no more than precession, but I like to call it "Sombrero effect".

Gyroscopic stability of Zondt emulated in MSC.ADAMS (2 min 23 sec)


Zondt sombrero (1 min 46 sec)
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