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Question

Asked by: Shawn Ostermann
Subject: Two questions about precession
Question: Forgive me if either of these questions have been answered here already. They are basic questions regarding precession but a casual search here and on the Internet has not provided me any insight.

1: Why does precession work at 90 degree angles? Does the rotation speed of the gyro not produce precession at different degrees from the originating force?


2: For a gyro-propulsion device, it takes gravity (dropping of device) to initiate the precession, right? (do I understand this wrong?) If this is true, how would the device work in space where there is no gravity?


Again, I know these are basic questions. Any insight into the answers will be most appreciated.


Thank you,

Shawn Ostermann
Date: 20 February 2006
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Answers (Ordered by Date)


Answer: DaveS - 21/02/2006 09:42:53
 Can't answer your first one. I still believe that the interpretation of precession and it's role in creating a working device is probably misunderstood and my own device does not factor in precession.

As for your second question. Take out the precession part and with relation to a device working where there is no gravity, this does raise the question as to whether it will work in space. Valid question.
The real question is how do the devices really work and if friction or gravity is a factor in allowing them to work. I have seen numerous models/devices and I strongly believe that in the absence of gravity, most devices will not work. Hence no use as a space drive.

On the same tack, a spinning gyro if fast enough, will create its own gravity but we are talking about stresses and technology that are way ahead of any feasable mechanics of today. In this case, this would mean that the gravity exerted by much weaker planetary bodies would become significant and then you could get a space drive within the solar system.

A device that could get material into local space, cheaply and efficiently would be of enormous impact though, allowing the building of alternative types of space drive in orbit.

Hard hat on and ducking.

DaveS

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Answer: Sandy Kidd - 22/02/2006 07:56:31
 Shawn,
There seems to be a bit of a difference of opinion amongst the contributors to this forum as to why gyroscopes precess i.e. rotate at right angles to the force driving them i.e. gravity.
This can get a little complicated so I will skip the bit in the middle, as I have no intention of trying to stuff my personal opinions down your throat.
The main attribute of any gyroscope is the fact that it will always react at right angles to an applied force.
Gravity is a vertical force so precession will always be in the horizontal plane.
Howsoever the reason for precession is not nearly as important as precession itself.

You are correct Shawn passive gyroscopic systems would be useless for the production of precession (in gravity free space) as they have nothing to drive them.
Many times on this site I have made mention to the fact that passive (gravity driven) gyroscopic systems, either in or out of a gravitational influence have nothing to offer as far as inertial thrust is concerned.

All is not lost however, as several of us, have for many years now, been accelerating gyroscopes in the horizontal plane, producing a continuous reaction to this applied force in the vertical plane. These accelerated systems produce some very interesting and unusual effects which include total reversal of the expected outputs
As all the operating parts of an accelerated system are subject to acceleration, gravitational influence is neither required, nor even wanted.
In the final analysis the only limitation to these accelerated systems is the strength of materials.
Don’t write Ezekiel out yet.
Sandy Kidd


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Answer: Jerry Volland - 22/02/2006 10:24:32
 Sandy,

You're absolutely right that any gyroscope will always react at right angles to an applied force. That's why it's called Angular Gyroscopic Propulsion. And the key word here is "react". The fact of the matter is, any thrust produced in this matter is a REACTION - either to gravity or to some other applied force. So an Inertial Propulsion device should never be called a "reactionless drive". I'm not going to say whether or not redirecting the applied force violates Newton's Law, but if it does, then Newton never studied a gyroscope.

Jerry

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Answer: Glenn Hawkins - 22/02/2006 15:10:30
 (Hub means the end of an axel, where hinging and pivoting happen, such as at the top of a tower, but otherwise may happen anywhere, anyway singularly, or with plurals hubs.)

Of course Sandy has it right. Just for fun, imagine that in zero gravity you have put a magnetic plate. On the North Pole side you’ve placed a gyro with aliened electro magnetic (off & on) South Pole axel hubs, while on the other side of the plate, the South Pole side, you’ve placed a gyro with aliened electro magnetic (off & on) North Pole axel hubs. This could result in accelerating the force applied, yes? Otherwise there might be many ways to configure parts construction to get the nearily same reactions as those furnished by gravity. Just for instance consider that as the hubs descended toward the plate you lessened the electro magnets force correspondingly so as to keep the force constant. In this just for a fun though, theoretically you can create similar conditions to or, as if by caused by gravity anywhere. This can result in the following statement: ‘By substitution of forces, passive reaction like precession can be simulated without gravity.’

Toying with this particular innovation of reason, you still find that: ‘A gyro cannot passively precess in the absence a passive force, that is to say by a consistent and constant magnitude of force, such as that found in gravity, or in this case by a human manipulative means.’

OTHERWISE: Without a lot of whoo-ty-do, I generally agree here with, Sandy very much.

G. H.

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Answer: Glenn Hawkins - 22/02/2006 15:18:36
 Continuing from the last thread. This brings us to the wild man, Dave S. (Hay Dave, keep it up please. I like to do the same thing for fun sometimes, yes, yes?)

I too floundered around with a question that has gone through your mind. Let me tell you how I came to a conclusion.

I placed a bit of mettle shaped like a ruler and about 8mm thick on a work bench and tacked it down. Then I spun up a gyro as fast as I could by use of 42”s of thread. Rotation must be very fast. The gyro was a tedco as pictured three times at the top of this site. Both my tedcos vibrate wildly at such speeds and are tricky to hold still as you would place one of them. I held the axels vertically. The wheel was of course then aliened horizontally. I placed the bottom hub on the bench next to the straight edge of mettle. I continued to hold the gyro to keep its axels vertical. As I did this I picked up a heavy shop hammer and swung it horizontally with ‘limited speed’ toward the top hub, which would result in driving the bottom hub pressure directly against the straight edge of the tacked-down mettle. Just before the blow landed I remove my hand from the gyro. What do you think happened?

The gyro precesses downward at a right angle to the applied force. This precession was almost too fast to see. There was but a little bottom movement opposite to that of top hub precession reaction. This slight bottom movement I’m pretty sure was caused from the slight friction of the greased hammerhead during the top hub contact. I should mention that I tried to keep the head of the hammer parallel to the straight edge of the tack-down mettle during the force contact to the top hub. I did a pretty good job of that by evidenced that the bottom hub movement was, as I said a slight, or negligible reaction.

I tried this several times got the same results. I will finish this post latter. For now I ask any, or all who think they might have a bit of fun with this, aside from the eventual destruction of a perfectly good gyro, ‘What can we discern from this almost too fast to see top precession?’

G. H.



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Answer: Glenn Hawkins - 23/03/2006 12:44:47
 We learn that gravity doesn't manipulate a change in angular momentum in some strange and complicated way that causes precession. Gravity acts as an applied force upon a curving alinement, the same as can be mechanically applied to dual axels to produce precession. A gyroscope therefore could be made to precess in zero gravity.

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