Question |
| Asked by: |
Blaze |
| Subject: |
How does the gyro precess in this situation? |
| Question: |
Scenario: A gyro (or flywheel) spinning in space free of all gravitational fields. Both ends if the flywheel axle can move freely in any direction and are the same size, shape and length from the center of the flywheel. Apply a force "up" on one end of the flywheel axle and at exactly the same time apply an equal force "down" on the other end of the flywheel axle. Keeping in mind that both ends of the flywheel axle can move freely in any direction, even with the forces applied, describe the precession motion of the gyro. Around what point does the gyro precess?
I want to see if anyone else comes up with the same answer as myself.
Blaze |
| Date: |
28 February 2015
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Answers (Ordered by Date)
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| Answer: |
Nitro - 28/02/2015 21:53:26
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| | Hiya Blaze,
Around its barycentre, however........
Kindest,
NM
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| Answer: |
Harry K. - 28/02/2015 22:08:49
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| | How long will the forced be applied? Continously?
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| Answer: |
Blaze - 28/02/2015 22:10:54
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| | The force is applied indefinitely.
Blaze
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| Answer: |
Blaze - 28/02/2015 22:12:20
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| | Hi Nitro.
However?
Blaze
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| Answer: |
Harry K. - 01/03/2015 02:43:22
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| | The spinning flywheel will simultaneously begin to rotate in the plane of the applied forces and in the 90 degrees deflected precession plane around its center of spinning mass, which is the barycenter of the mass system in this case.
The rotation in direction of applied forces (=tilting torque) will be present until the flywheel is accelerated from zero to precession speed. After precession speed is achieved, the flywheel rotates only in precession plane at constant speed as long as the forces are applied.
If the forces are removed, the stored kinetic energy (=angular momentum) in precession movement will cause the flywheel to move back in counter direction to the plane of the formerly applied forces, i.e. back to the initial position of the flywheel.
What is the reason for this often discussed question, Blaze?
Regards,
Harald
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| Answer: |
Blaze - 01/03/2015 16:00:02
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| | Hi Harald and all. Harald, thank you for your explanation. I agree with almost all of your explanation except a bit of what happens when the forces are removed but that part is not important to the point of this discussion. I want to ask another question or two regarding this topic before revealing the reason, in an attempt to prevent any biases from getting into the explanations.
The answer to the next two questions may seem obvious but I still would like everyone's explanations.
Why does the gyro rotate about the center of spinning mass, which is the barycenter of the mass system in this case?
Why doesn't it rotate around one of the ends of the axle?
The second scenario is this:
A gyro is spinning with one end of the axle sitting on a pivot and the pivot sitting on a table in earth's gravity (say in your kitchen or work shed) and the other end of the axle being held by yourself. A perfect release of the axle end being held by you is executed. The free axle end can now move in any direction even though a force is being applied (gravity). The pivot end of the axle has the opposite force being applied to it by the pivot (which according to physics is one part of the force couple).
Now for the questions for the second scenario, some of which, again, will seem to have obvious answers.
1. First the easy one. After the gyro is up to full precession speed, around what point does the gyro precess?
2. Immediately after release but LONG before the gyro is up to full precession speed, around what point does the gyro precess?
3. Besides gravity providing the force and the pivot providing the opposing force to the pivot end of the axle, how is this scenario different than being in space?
Blaze
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| Answer: |
fahkei@gmx.de - 01/03/2015 16:56:46
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| | Hi Blaze,
Regarding scenario 2: is the pivot fixed rigid to the table surface or may it move in any of the 2 dimensions on the table?
I will wait for opinions from other contributors before presenting my own ideas.
Anyway, all of these questions have been discussed several times here in the forum in the past, however, buried somewhere in the downs of this forum and maybe at the time before you joined this forum.
Regards,
Harald
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| Answer: |
Blaze - 01/03/2015 17:39:39
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| | The pivot is "free" to move in 2 dimensions on the table, however there will be the typical friction between the pivot and the table.
Blaze
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| Answer: |
Nitro - 01/03/2015 18:08:22
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| | Hiya Blaze
The “however” is that your question would seem to be about an unwritten projection and not solely your original question.
OK, I’ll bite. I’ll guess you want to know:- if it rotates round the barycentre in your example then it must surely rotate around its barycentre when supported from one end and a force (typically gravity) causes an acceleration (force) to be applied to the other (free) end. This is where the gyro shows its weird side. If it is a perfect gyro (no such thing – like the perfect Op-Amp – exists but you can get near enough to check this out) the centre of rotation changes to the supported point (though not quite because it won’t be a perfect gyro).
I cannot bang on enough, it seems, about Nitro’s first law. A GYRO WILL PRECESS EVERY FORCE APPLIED TO CHANGE ITS AXIAL ANGLE – NOT JUST THE FORCES YOU HAVE THOUGHT OF!!! Please try and think of all the forces that will appear at 90 degrees to their application; inertia, centrifugal force, acceleration, deceleration etc., ad inf..
kind regards
NM
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| Answer: |
Blaze - 01/03/2015 21:25:29
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| | Hi Nitro. You are correct about what I am ultimately trying to solve. In posing the questions I may have come up with the reason or at least a part of the reason for the different response of the gyro when on the table.
The answers to the questions in the second scenario are as follows:
1. around the pivot
2. around the center of mass of the gyro.... maybe, or at least until it gets up to a significant fraction of the precession speed...maybe, see answer 3.
3. The big difference is where the forces are being applied. In space the force is being applied at both ends of the axle. On the table it is not quite the same. It is true that the opposing force is being applied at the pivot end of the axle. The other force (gravity) is, for all intents and purposes, being applied at the center of mass of the gyro, NOT specifically at the end of the free end of the axle like it was when in space. The question then becomes, does this make any difference in the response of the gyro?
cheers,
Blaze
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| Answer: |
Harry K. - 01/03/2015 22:35:03
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| | Hello Blaze,
Regarding your answer to 1 I fully agree, but I do not agree with your answers in regard to question 2 and 3.
Before I explain why I disagree please explain why the flywheel rotates around the pivot in question 1. What exactly is the reason for this behavior?
Regards,
Harald
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| Answer: |
Blaze - 02/03/2015 02:26:49
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| | Hi Harald.
"What exactly is the reason for this behavior? "
What exactly indeed. Isn't that what everyone wants to know? Of course there are numerous explanations, opinions and thoughts on the matter from various people who have varying degrees of belief that they have the only "true" reason. And of course I have my own explanation which to me makes sense and I have proposed somewhere on this site in another posting which some may agree with and most probably don't. The full explanation would take a while to write but to be brief, during steady state precession, it is a combination of the following:
- the pivot "holds" the gyro in place during precession due to the friction between the table and the pivot (I think that most people don't agree with this point however I have posted somewhere on this site a video showing that once steady state precession is achieved the gyro pretty much rotates about its center of mass when the platform the pivot is attached to is free to rotate and move in any direction in two horizontal dimensions, better experiments may yield better or perhaps even different results)
- the pivot is shaped like a cone or has a large base and for a good reason (so that it doesn't fall over during precession and it is not just the dead mass that is trying to topple the pivot; again most would not agree)
- the combination of the momentum of the gyro trying to make it go in a straight line (like the tree house experiment) and the gyro trying to rotate about its center of mass as it precesses, helps to keep the pivot end of the axle on or nearly on the pivot which helps the gyro to go around the pivot (maybe not the best wording but I am trying to be brief)
Question two of the second scenario deals with the very first stages of the start up of the gyro before it ever reaches steady state precession. It seems that most people find the brief fraction of a second that the gyro takes to get to steady state precession an inconvenience, or an phenomenon that is too brief to bother worrying about, so they tend to ignore it. I have done many experiments and have quite a few videos of exactly what happens when a gyro starts to the time it gets to steady state precession. I am able to reproduce on paper, a graph, based on first principles, that matches the experiments, so I am quite comfortable about what actually happens during that brief fraction of a second that it takes for the gyro to get to steady state precession.
regards,
Blaze
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| Answer: |
Harry K. - 02/03/2015 09:40:13
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| | Blaze, we are not far away from each others point of view regarding gyro behavior under certain conditions. There are only some subtleties which I see a bit different but these subtleties are in my opinion important for the basic understanding why a gyro/flywheel behaves in a certain manner and not different.
Later more when I am back at home.
Regards,
Harald
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| Answer: |
Harry K. - 02/03/2015 20:07:48
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| | Hi Blaze,
Here are my answers regarding Scenario 2:
Q 1:
"First the easy one. After the gyro is up to full precession speed, around what point does the gyro precess?"
The answer is not at all easy. Around which point the gyro will rotate during steady state precession depends on some factors:
- mass of the overhanging groscope
- geometry of the gyroscope (flywheel radius (r), geometric shape)
- Spinning rate of the flywheel
- distance to the pivot (I call it hub radius) which determines the acting tilting torque
- mass of the Pivot
- coefficient of friction between the Surface of the pivot and the Surface of the base (the table in this case)
First of all I agree about that a gyro or flywheel will ALWAYS response to an applied torque from its center of spinning mass. I always stated this fact here in the forum but I know many other contributors do not agree. However, based on all given parameters the gyro will behave different to applied forces / torques.
I have prepared a drawing which shows in a symbolic for the acting forces / torques but unfortunately it is still not possible to upload documents here. I hope Mr. Turner will update the site soon as he promised it last year. If somebody is interested please give me a short note by email.
Under gravimetric conditions the following forces / torques are involved with an overhanging gyroscope:
- Mass (mg), angular momentum (LG) and spinning rate (wG) of the flywheel
- Distance from the flywheel’s center of mass to the pivot (lever arm length R)
- Mass of the pivot support -> not considered here
- Tilting torque caused by gravity (Mt)
- Angular momentum around pivot caused by the flywheel’s dead weight mass (LP)
- Angular momentum of the pivot mass around the flywheel’s center of mass -> not considered here
- Angular momentum of the flywheel around the center of spinning mass in precession plane -> not considered here
- Coefficient of friction of surface pivot and base (µ)
- Other dead weight masses (lever arm, cages, etc.) -> not considered here
- Other friction losses -> not considered here
As you can see I did not considered some factors to make the following expressions not too confusing. However, these factors have to be considered for more accuracy.
As stated before the flywheel or gyro always response from its center of spinning mass. However, the real center of precession may be positioned at the pivot, the flywheels center of spinning mass or somewhere between these both points.
Mainly two response torques will decide the exactly position of the center of precession:
1. The torque given by the flywheel’s dead weight mass which may turn around the pivot and the distance (R) to the Pivot
2. The torque given by the pivot and the coefficient of friction which may turn around the flywheel’s center of spinning mass and the distance (R) to the flywheel’s center
Unfortunately I have to do some maths for further explanations.
1. Calculation of the torque LP (=angular momentum) caused by the flywheels dead weight mass
LP = JP * wP; wP = Mt / LG
LP = mg * R^2 * Mt / LG
LP = mg * R^2 * mg * 9.81 * R /(JG * wG)
LP = mg^2 * R^3 * 9.81/ (mG * r^2 * wG)
***LP = mg * R^3 * 9.81 / (r^2 * wG)***
2. Calculation of the torque MP caused by the pivot
Note: during steady state precession the weight of the gyro mass will be transferred to the pivot.
MP = FN * R; FN = µ * FG
MP = µ * FG * R
***MP = µ * mg * 9.81 * R***
3. In both calculations the following same variables are present: mg, R, 9.81
Thus LP can be transformed to:
***LP = MP * R^2 / (r^2 * wG * µ)***
The term R^2 / (r^2 * wG * µ) has to be considered now:
1. If R^2 / (r^2 * wG * µ) = 1 then LP = MP, i.e. the precession center will be at R/2
2. If R^2 / (r^2 * wG * µ) < 1 then LP < MP, i.e. the precession center will be closer to the pivot
3. If R^2 / (r^2 * wG * µ) > 1 then LP > MP, i.e. the precession center will be closer to the flywheels center of spinning mass
4. If R^2 / (r^2 * wG * µ) = 0 then LP =0 and MP = 0, i.e. the precession center will be at flywheels center of spinning mass
This case can only happen if there is no friction between the surfaces of pivot and base!
This is the reason why a symmetric gyro/flywheel system will always precess around the center of its spinning mass in space without influence of gravity and friction.
Q2:
“Immediately after release but LONG before the gyro is up to full precession speed, around what point does the gyro precess?”
This is difficult to answer because in this situation the flywheel will drop until steady precession speed is achieved. Thus it could be a chaotic mixture of the above stated 4 possibilities. I don’t know.
Q3:
“Besides gravity providing the force and the pivot providing the opposing force to the pivot end of the axle, how is this scenario different than being in space?”
Already explained above under point 4:
“If R^2 / (r^2 * wG * µ) = 0 then LP =0 and MP = 0, i.e. the precession center will be at flywheels center of spinning mass
This case can only happen if there is no friction between the surfaces of pivot and base!“
Best regards,
Harald
P.S. Hope the format of the text will be ok...
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| Answer: |
Glenn Hawkins - 03/03/2015 00:46:36
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| | In Space: Each end of the shafts could be powered by a tiny rockets aligned in opposite directions. When they are fired precession does not follow. Torque from the rocket forces is converted to right angle reaction torque. The direction of both; the force torque and reaction torque, continuously twist around the single center of mass. In very fast dually twisting the gyro would appear as a partially invisible spear of motion. I described this motion on here ten years ago as; a state of ‘tumultuous motion’.
I favor Momentous’ description of instantaneous reaction, where if I understand, the inertia created remains in the force area and not the reaction area. If this were true, when the rockets were shut down; reaction torque, (what is being call precession) would instantly cease to exist.
If I am correct and depending on the geometry and points and magnitude of mass, the breaking of all tumultuous motion of any kind, including the force area could happen incredibly fast.
This of course is in opposition to Harry’s clever and thought provoking postulation.
Glenn,
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Harry K. - 03/03/2015 09:36:41
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| | Hi Glenn,
"I favor Momentous’ description of instantaneous reaction, where if I understand, the inertia created remains in the force area and not the reaction area."
Please explain by utilisation of pysical laws why you favor this idea. Or prove me wrong by utilisation of pysical laws.
Or do you only believe something? In this case it does not play any role what someone may believe or not. Use physical laws to explain your ideas, otherwise we are turning in cycles. ;-)
Regards,
Harald
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Glenn Hawkins - 03/03/2015 12:42:03
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| | Harry,
Have you been laboring all this time under the impression that you have proved something? To whom? Proved to whom? Name one person.
Glenn,
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Harry K. - 03/03/2015 15:43:14
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| | To whom, Glenn? - To all who are really interested to know (not believe!) the physics behind some behavior of a spinning flywheel.
Regards.
Harald
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Glenn Hawkins - 03/03/2015 17:15:59
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| | Name one.
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Glenn Hawkins - 03/03/2015 17:39:55
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| | Harry, you are working in a tong not native to you own and doing a good job, sometimes getting fowled up. Let me explain my post to you.
“In Space: Each end of the shafts could be powered by a tiny rockets aligned in opposite directions. When they are fired precession does not follow. Torque from the rocket forces is converted to right angle reaction torque. The direction of both; the force torque and reaction torque, continuously twist around the single center of mass. In very fast dually twisting the gyro would appear as a partially invisible spear of motion. I described this motion on here ten years ago as; a state of ‘tumultuous motion’.
I favor Momentous’ description of instantaneous reaction, . . . .WHERE IF I UNDERSTAND,. . . the inertia created remains in the force area and not the reaction area. . . . .IF THIS WERE TRUE. . . . , when the rockets were shut down; reaction torque, (what is being call precession) would instantly cease to exist.
IF I AM CORRECT. . . ..AND DEPENDING ON. . . . . the geometry and points and magnitude of mass, the breaking of all tumultuous motion of any kind, including the force area . . . . COULD . . . happen incredibly fast.
This of course is in opposition to . . . HARRY’S CLEVER. . . . and . . . . THOUGHT PROVOKING . . . . postulation.”
////////////////////////////////////////////////////////
Harry my post suggests uncertainty. It likes conviction and claims of certainty. It does not challenge you in any way. In fact you were complemented twice as being smart and having good ideas.
It is difficult for you to read me Harry. I have not changed in any way. What is there in my post to challenge? It is all speculation. How do you expect me to give prove to speculation? In speculation there is no proof. That is the point of it.
I am done here. Catch you later.
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Blaze - 03/03/2015 23:34:08
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| | Hi Harald. Thanks for the explanation. I think the part about
"...the precession center will be at flywheels center of spinning mass...This case can only happen if there is no friction between the surfaces of pivot and base!"
will not agree with most people here but I do in fact agree with most of your explanation.
Hi Glenn.
"I favor Momentous’ description of instantaneous reaction, where if I understand, the inertia created remains in the force area and not the reaction area. If this were true, when the rockets were shut down; reaction torque, (what is being call precession) would instantly cease to exist."
Regarding the gyro in space, you are correct that "reaction torque, (what is being call precession) would instantly cease to exist." but motion would continue. Once precession has started there is momentum which as you know is simply movement of mass. In space the motion of the gyro mass does not stop moving simply because the input force (the rockets) is removed (precession, depending on how you define it, stops but not motion). The motion of the gyro mass will only stop if an opposing force of some kind is applied to bring the motion to a stop. That is NOT to say that precession motion will continue, but motion, a different motion than precession, will continue until the gyro is brought to a stop by another force. Remember this is in space. On earth the precession would come to a stop when the input force was removed because the gyro would be physically climbing up the gravitation well of earth. It would be exchanging its horizontal (precession) motion for potential energy. Of course when it got to the maximum potential energy it would start falling again due to gravity.
I have done an experiment somewhat similar to the gyro in space but on earth and with a balanced system to nullify the effect of gravity and the when the input force causing precession is removed the precession motion does indeed stop, but motion does continue, just not in the precession plain. I have posted this elsewhere on this forum in the past.
cheers,
Blaze
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Glenn Hawkins - 04/03/2015 02:21:50
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| | Hi Blaze,
You said, "reaction torque would instantly cease to exist.” but motion would continue.
I don’t think so. Allow me to quote myself in context, “Momentous’ description of instantaneous reaction, . . . where if I understand . . . the inertia created remains in the force area . . . and not the reaction area. . . . If this were true, . . . when the rockets were shut down; reaction torque, (what is being call precession) would instantly cease to exist.”
I stand by this.
If motion continued in the previous force plane whether by momentum or any means, reaction would result in what is being called the precession plane. You cannot have either without the other. It is about action and reaction. Think of it this way, ‘twist causes twist’. As long as momentum is acting all reactions continue to react. Motion continues. We've sort of missed the point.
The torque reaction is not true procession. I know you already know the actions I am about to describe, but I don’t know if you know this action is in fact – not precession. This gyro I postulated, being equally forced at each shaft end and equally free to move at each shaft end would have no platform to support resistance. Thereby the gyro could not precess in a wide arch around a pivot point, as no such point exists. I perceive the meaning of the word precision describes only and not more than; the orbit of a gyroscope around a pivot.
This is why I said of the reaction torque, “. . . which is being called precession on here.”
By tremulous motion, I mean to describe a number of complex actions I think you already know; but it is a group of actions that is not referred to on here by name. I meant to give it a descriptive name and so I did ten years ago. The explanation is as follows; the rockets would apply force in a revolving plane; a plane that twists as it rotates. An example is a cue ball shot with reverse English and right angle English at the same time. It is done all the time in billiards. When the cue ball strikes solidly into the object ball, for an instant it remains in one place rotating in two directions at right angles to one another. The rotation plane is twisting around its center of mass; also the reaction plane is twisting around the same center point.
You say, “In space the motion of the gyro mass does not stop moving simply because the input force (the rockets) is removed. . .”
But I say, once the force stops, the breaks go on. This is because the force torque and reaction torque are in reaction against one another. We can think of many examples we have played out. Each applies breaks to the other.
I pointed out, “. . . depending on the geometry and points and magnitude of mass . . . the breaking of all tumultuous motion of any kind, including the force area could happen incredibly fast. Again, this is because the two are opposing forces. I did not say momentum died. I said breaking could be very, very fast.
Cheers Blaze
Harry hi,
I should add I wrote, “I favor Momentous’ description.” I did not say you were wrong, or that I was certain of everything I mentioned. What the guys entering prison are told is, “Keep a cool tool and you’ll be hard to beat.” There is a double meaning somewhere there, but it primarily means stay calm. I should add, ‘I am being friendly and wishfully funny though there is no such thing as humor on here..’
Latter bozs,
now I gotta get some things done though it pains me to leave you this way.
Glenn
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Blaze - 04/03/2015 03:57:00
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| | Hi Glenn. See http://www.gyroscopes.org/forum/questions.asp?id=1558 for a video of the balanced gyro system I was talking about.
cheers,
Blaze
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Glenn Hawkins - 04/03/2015 06:47:24
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| | Hi Blaze,
I checked the articles you direct me to. Thank you.
Yes, I was sure you knew as I mentioned you did. Still, I correct the description of reaction torque as described in your scenario as ‘precession motion’, which I was equally sure you had not distinguished as not being precession at all.
Yes to you; force couple exactly.
A GYRO WILL PRECESS EVERY FORCE APPLIED TO CHANGE ITS AXIAL ANGLE
Nitro is correct. I will add for belabored clarity. In the space example, the direction of force applies itself in a constant flux of redirecting action and reaction; to twist and tumble from and into new and changing planes. At high speed it would appear as a blurred spear of motion never moving from its point in its XYZ grid.
As for the pivot on the table, surly everyone has had access to all the various ideas as Harry so much as said.
to digress a second; I do not think pivotal friction works exactly the simple way it seems it should. I really don’t know. One way is that friction is exacting and iron-clad logical; to think the other way is annoying with never a definitive answer in sight. This way is almost mystical and although I do not believe in mysticism, it is difficult to put away these powerfully suspected phenomena that nobody has disproved. Your example with the wagon is very powerful, bravo, but it is not conclusive to some minds on here for reasons that I tire of mumbling about near innocently. I really believe there is something going on there, something between known physics and something not completely known, or rather not understood though mostly everything I believe, will be in compliance with physics.
Well it seems I have not escaped these surly bonds of earth yet. I am back to posting.
Cheers,
Glenn
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Harry K. - 04/03/2015 10:32:12
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| | Hi Blaze and Glenn,
I wrote on 01.03.
"If the forces are removed, the stored kinetic energy (=angular momentum) in precession movement will cause the flywheel to move back in counter direction to the plane of the formerly applied forces, i.e. back to the initial position of the flywheel"
This is not completely correct. Once the forces being applied they cause the acceleration from zero to precession speed. That means the forces which generate a torque perform physical work which is stored in precession movement. This physical work was initially caused by the forces rotating a bit in direction of the applied torque (tilting torque).
If the forces being removed, the tilting torque does not exist anymore, however, the physical work stored in precession is still existent and will not disappear in the absence of gravity and thus in the absence of friction.
The resulting movement after the forces being removed will be a kind of nutation, i.e. a for- and backward rotation between the 90 degree deflected planes or an resulting movement between both planes.
Sorry I did not considered this in my answer from 01.03.
Regards,
Harald
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Nitro - 04/03/2015 10:34:14
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| | Dear Blaze
Gee thanks for wasting more of my life - why didn't you put up a direct link to the Vimeo? You made me take two steps instead of just one?
The orbiting motion says that only one gyro was spun causing the other to be a dead weight causing it to behave as to be expected of a part gyrodynamic/part Newtonian fashion. This, when applying Nitro's first law, explains the orbiting motion and also the wobble (nutation?) caused when a simple gyro or top has decreasing gyrodynamic effect and increasing Newtonian effect when the spin speed is much reduced. The non gyrodynamic part shows the increasing Newtonian inertia and mass effects which the remaining gyrodynamic part precesses.
NITROS FIRST LAW RULES!
Kind regards
NM
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Nitro - 04/03/2015 10:55:02
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| | Harry
Sorry, further to my post above, I didn't notice your post. You seem to be saying, as Blaze does, that the gyro, in the space example that Blaze gave, will keep moving due to inertia when the force/s precessing it is/are removed. Unless the gyros are spinning so slowly that they start to exibit Newtonian effects more than gyrodynamic effects as in my example above - and, indeed in Blaze's Vimeo,- the precesion will stop immediately. Or, I should say, almost immediately as there is no such thing as a perfect gyro. The effect of inertia like everything trying to change the axial angle of a gyro is precessed so the effect of inertia - while still there - disappears in a 90 degree displacement.
NITRO'S FIRST LAW RULES
Kind regards
NM
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Nitro - 04/03/2015 11:02:46
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| | Dear all,
Sorry, more on the Vimeo:-
Blaze I am sure you will have tested that arrangement with both gyros spun and if I am right - which of course I am - you will see the precession stop pronto-ish when the down force on one side is removed. I say "ish" because as you wont get both gyros spinning in synchrony there is bound to be a bit of Newton hanging about to sod up the effects a little
Kind regards
NM
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Glenn Hawkins - 04/03/2015 13:39:46
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| | Hello all,
Disregard the top for it has a pivot.
Disregard the ratio of dead weight for its effect is only fractional.
Take in account only two rockets firing oppositely at each shaft-end.
When the outside force is removed the system does not coast. It stops.
In a closed system ‘precession’ from momentum; is equal to the resistance from precession.
If you can get this one paragraph below, going back to the simple, understood and digest; the knowledge will be forever yours.
…………………………………………………………………
This is what inertia is: the force to cause movement is equal to the force to stop movement. The torque working to bend the centrifugal effect in the flywheel is equal to the force working to stop the bending. The forces are applied in equal and opposite direction against the centrifuge in the flywheel.
…………………………………………………………….
This explains why; whenever angular momentum is very strong, and whether ‘precession’ is extremely slow or extremely fast all torque and subsequent movement stops nearly immediately when applied force stops. It explains near instantaneous that one poor man has struggle and struggled to make understood.
Mr. Kidd was the first to note that forced precession in his devices was not really precession.
Nitro was the first to champion the condition of instantaneous.
I just hang out here once in a while.
Glenn,
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Blaze - 04/03/2015 13:52:14
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| | The whole point of the experiment was that when the input force causing precession is removed the momentum (the movement imparted to the device) doesn't just disapear, the momentum has to continue in some manner, it is conserved. The motion of the gyro mass will only stop if an opposing force of some kind is applied to bring the motion to a stop, which is in the form of friction from the string, in the experiment. In space the circling motion would wound not change as long as the gyros spin at a constant rate.
I have in fact done the experiment with both gyros spun up and it performs much the same except that the circling motion is smaller for the same force input or I can put in more force to get the same size circling motion. This experiment could be done with a central pivot at the balance point instead of the string and it would perform the same way.
regards,
Blaze
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Nitro - 04/03/2015 14:18:35
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| | Blaze
Wrong! If, as you say, you did do the test with both gyros spun (hopefully in the same sense when looking into the shaft from each end). Then, according to your idea of inertia of gyros, the circular displacement should be at least the same due to them having the same mass. And the inertial movement must last for exactly the same time after the displacing force is removed. This wont happen due to Nitro's first law. Its circular displacement seen in the vimeo and its duration after force removal will be much, much less.
If you would like to put the test, with both gyros spun up, on vimeo you will see, as will all else, that there is little if any residual movement after the removal of the displacing force. What small amount of residual movement there is will be, as stated before, caused by the inevitable mismatch of gyro spin speeds.
Kind regards
NM
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Harry K. - 04/03/2015 15:09:17
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| | Blaze,
I fully agree and you already demonstrated this fact in your video.
Nitro,
I have to admit that I do not full understand you first passage.
My opinion is that energy is necessary to accelerate the gyro to precession speed. The gyro receives additional angular momentum beside its already existing angular momentum in spinning plane.
This additional angular momentum (=kinetic energy) remains in the system as long it will not be extracted by e.g. friction.
Under gravitational conditions this additional energy will allmost immediately disappear or better transformed into heat by friction and thus the gyro stops movement except of its spinning movement.
If you are convinced that the precession movement disappears after removement of the applied torque then you have to explain where this energy remains? Or you are the opinion that no initial energy is necessary to accelerate the gyto to precession speed, what is definitely not true!
Regards,
Harald
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Blaze - 04/03/2015 16:14:36
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| | Hi Nitro. When the test is done with both gyros spinning the "same" way when looking from one end of the apparatus the results are as I stated before. The reason for the smaller circles with both gyros spinning after the input force is removed is because there is more gyrodynamic force to make the "conversion of momentum" into the circles. When only one gyro is spinning it has to overcome and convert the weight of the non-spinning gyro (which is really just a lump of matter) into circular motion.
When the test is done with both gyros spinning the "opposite" way when looking from one end of the apparatus the results are, of course, that the device keeps moving in the direction of the input force after that force is removed. The reason for this is, of course, that the gyrodynamic forces from the two gyros are cancelling each other out.
Why don't you simply build a similar device and try it yourself instead of speculating what happens? It certainly isn't a difficult project.
cheers,
Blaze
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Blaze - 04/03/2015 16:40:27
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| | One thing I forgot to mention. When both gyros are spun up, after the input force is removed, the circling motion is smaller but it is also faster.
cheers,
Blaze
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Glenn Hawkins - 04/03/2015 17:04:04
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| | Hang in there Blaze. I sense you are frustrated, buddy.
Everyone put in your search engines,
‘gyroscope experiments in space and freefall’
Or the long address:
https://video.search.yahoo.com/yhs/search;_ylt=A0LEVu7tK_dUyRkATmMnnIlQ;_ylu=X3oDMTB0ZjNuMHJ1BHNlYwNzYwRjb2xvA2JmMQR2dGlkA1lIUzAwM18x?p=gyroscope+experiments+in+space+and+freefall&hspart=mozilla&hsimp=yhs-001
Of course you knew gyroscopes are used as stabilizing devices, because they resist changing their orientation. That is why they are uses and I think these videos are right up everyone here’s alley.
Devices of resistance and stabilization never
the nevertheless, once set to tumbling they will continue tumbling. The best of the five videos to demonstrate this is the one with the deck of cards. I can no longer see this video because of yahoo and so I am pointing this out to the best of my recollection.
Yahoo tricked me and hijacked my search engine while denying me an immediate way to get rid of them. The whole world has become that way. I am so sick of such sneaky attacks for a fractions of a penny from sponsoring advertisers I could kill whoever is responsible if I knew who. Consequently I cannot see Blaze's video and so I don't know how "two" videos got here, and won’t until == through time and aggregation I make time to pay a service mucho dollars to remove the advertising bug, yahoo. America’s FCC isn’t worth a sh*&^%(#. It won’t do ANYTHING to protect the airways and phone lines.
Pissed with them, but happy with you researchers,
Glenn
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Nitro - 04/03/2015 17:04:19
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| | Dear Blaze and Harry,
Been there don that got the tee shirt.
Blaze I think your observations were flawed, which they were, because you used a toy gyro with poor spin speed and mass/spin matching causing much Newtonian noise to deceive you.
Harry I think you are letting your undoubted ability in maths to blind you to what can clearly be observed elsewhere.
I was going to refer you both to one of the Laithwaite lectures on this very site showing quite clearly what I have observed many times with motorized test rigs myself. On a gambled gyro with horizontal shaft, when a weight is applied to alter the axial angle of the shaft it precesses instantly - no delay no waiting for acceleration as the maths and Newtonian law would suggest - instantly. Instantaneous decelloration also happens when the weight is lifted - instantly - not waiting for inertia to get absorbed by friction and no waiting, again, as the maths and Newtonian law would suggest - instantly.
Alas this website link to the Laithwaite test seems broken so.......
Do the test again yourself with eyes open this time you cheeky little whippersnapper.
kind regards
NM
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Glenn Hawkins - 04/03/2015 17:07:06
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| | Would be nice if we could edit.
Hang in there Blaze. I sense you are frustrated, buddy.
Everyone put in your search engines,
‘gyroscope experiments in space and freefall’
Or the long address:
https://video.search.yahoo.com/yhs/search;_ylt=A0LEVu7tK_dUyRkATmMnnIlQ;_ylu=X3oDMTB0ZjNuMHJ1BHNlYwNzYwRjb2xvA2JmMQR2dGlkA1lIUzAwM18x?p=gyroscope+experiments+in+space+and+freefall&hspart=mozilla&hsimp=yhs-001
Of course you knew gyroscopes are used as stabilizing devices, because they resist changing their orientation. That is why they are uses and I think these videos are right up everyone here’s alley.
Devices of resistance and stabilization nevertheless, once set to tumbling they will continue tumbling. The best of the five videos to demonstrate this is the one with the deck of cards. I can no longer see this video because of yahoo and so I am pointing this out to the best of my recollection.
Yahoo tricked me and hijacked my search engine while denying me an immediate way to get rid of them. The whole world has become that way. I am so sick of such sneaky attacks for a fractions of a penny from sponsoring advertisers I could kill whoever is responsible if I knew who. Consequently I cannot see Blaze's video and so I don't know how "two" videos got here, and won’t until == through time and aggregation I make time to pay a service mucho dollars to remove the advertising bug, yahoo. America’s FCC isn’t worth a sh*&^%(#. It won’t do ANYTHING to protect the airways and phone lines.
Pissed with them, but happy with you researchers,
Glenn
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Nitro - 04/03/2015 17:29:23
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| | Been there don (?); decelloration? What happened to my ejerkashun?
NM
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Harry K. - 04/03/2015 18:10:21
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| | Glenn,
/OT on:
Regarding "Yahoo hijacking" I believe I had the same problem. My internet welcome page was exchanged by the Yahoo search site and whatever I tried to eliminate the Yahoo toolbar from my System (uninstall the toolbaar software, changing the welcome page site manually...) I got not rid from this damned Yahoo search page. It was always installed again after a rebnoot of my system (Win 8.1). This damned advertising software is deep buried in the system.
Only this tool helped me to eliminate this damned software from my system:
AdwCleaner
http://general-changelog-team.fr/en/tools/15-adwcleaner
Try it but better uninstall this tool afterwards. You never know...
/OT off
Regards,
Harald
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Harry K. - 04/03/2015 18:20:14
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| | Glenn,
Sorry a mistake. This is the correct software:
Malewarebytes:
http://www.malwarebytes.org/mwb-download/confirm/
Regards,
Harald
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Blaze - 04/03/2015 18:48:39
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| | Hi Nitro. If I am wrong then prove I am wrong by doing the experiment and getting different results. Isn't that how the scientific method is supposed to work? If other independent researchers repeat the experiment and get the same results then the original experiment is ok, if not it is flawed. So, do the experiment and post the results.
When you say "... the shaft it precesses instantly - no delay no waiting for acceleration" I certainly hope you mean that precession starts "instantly", not that full speed precession happens instantly because it does not. Not even for a small gyro system spinning at high speed.
The same goes for stopping precession by removing the weight. According to you "Instantaneous decelloration also happens when the weight is lifted ...."
Precession may stop instantly (depending on how you define precession) but movement of the gyro does NOT stop instantly. It takes some small amount of time for the gyro to come to a stop from full speed precession just as it takes some small amount of time to get up to full speed precession from its start. I agree that to the naked eye it certainly looks instant but even with the slow 15 frame per second camera I used to video the the "drop" of the gyro when starting, it is very clear that the gyro is not moving at full speed instantly. I did these tests videoing the starting of a relatively small 5 inch gyro and a large 24 inch gyro with the same results. Full speed precession is NOT instant.
Of course you may not mean full speed precession happens instantly only that precession starts instantly.
regards,
Blaze
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Harry K. - 04/03/2015 19:04:21
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| | Hi Nitro,
It depends what you understand under "instantly". Did you make some measurements and if yes, how did you do it? If precession speed is low, based on the gyro shape or gyro dynamics, the necesary input energy will be low as well and thus it could be that a small amount of movement in direction of the applied torque may not be noticeable.
You did not answered my question where the additional energy remains after the removal of the torque. Or do you think a precessing gyro ia a perpetual Motion machine which receives ist additional kinetic energy (precession movement) from nowhere?
By the way maths is only a tool for me to prove or disprove physical related theses by logic. Nothing more and nothing less. The fine little Thing with maths is that threre is no "maybe" or a "believe" but only a "true" or an "untrue".
Regards,
Harald
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Glenn Hawkins - 05/03/2015 01:45:02
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| | Harald, you are a peach for filling me in on your experience with our wonderful S.O.B. Yahoo. I have the exact protection you named. It stays on all the time and I haven't had a problem with it, such as it planting pay-me fake viruses to fix me. I can see how irate you are. We pay for a service and a third party sneaks in and fowls-up our computer in order to forces us to become aware of it's commercials.
I hope the space videos of gyros coincided with your predictions, that is, supplied you with supporting proof of your beloved physics. Actually I know physics is the way,, but mysticism runs amouck here at times and every so often I am one of the ducks in the puddle.
All you guys try to stay out of prison. There is subversion going on here with ever other post and the physics cops have learned about you.
Glenn,
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Harry K. - 05/03/2015 18:09:54
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| | Hi Glenn,
The malewarebytes tool scans the complete system. If it finds any maleware you can remove it from your system. Afterwards I deinstalled the tool, i.e. it never works in the background. Maybe you have installed another tool which is maleware as well?
Regards,
Harald
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Glenn Hawkins - 05/03/2015 22:16:28
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| | I have,' malewarebytes Anti-maleware'
I don't know if your 'malewarebytes tool' is different?
Thank you again, Harry.
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Sandy - 05/03/2015 22:45:55
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| | Evening everyone,
I tend not to get involved in hypothetical discussions of this nature but now and again I feel I must add my penny’s worth.
I was in fact going to offer my thoughts on a couple of other issues but because I am a nice person, I decided to spare you all.
Nitro you are correct in your statements that the reactions displayed when the weight is added and removed to a gyroscopic system in precession are instantaneous.
Some of us are aware that there is no angular momentum generated in a gyroscopic system in precession so any increase or decrease in rotating mass will be instantly accommodated for by change of precession speed, producing a system which still has no angular momentum.
With no angular momentum present acceleration will be infinite, which is pretty quick.
Regards,
Sandy.
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Blaze - 06/03/2015 01:11:07
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| | Gentlemen, please.
While "the reactions displayed when the weight is added and removed to a gyroscopic system in precession are instantaneous" that only applies to the reactions, not the movements or motions. The time required to go from zero to full precession speed is NOT instantaneous. Nothing in the universe can go instantaneously from zero velocity to a given velocity of, say, several inches per minute (or faster) that a gyro precesses at. It takes time to get up to speed, even if it is a very short time it is not instantaneous.
Consider this. If acceleration to full precession speed for a gyro is infinite, the gyro would not fall down at all as it starts to precess. There would be no need for it to do so because as soon as is starts moving it is instantaneously going full precession speed. What would cause it to drop if it is already going full precession speed? In order for the gyro to have infinite acceleration it would have to be zero inertia.
However, believe what you will.
regards,
Blaze
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Harry K. - 06/03/2015 09:34:09
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| | Gentlemen,
In nature no physical instantaneous effects are possible and known. Name only one single instantaneous effect aside from precession (which is however not true)? All physical actions or reactions proceed in a continous function over the time caused by the inertia of the involved masses. Please forgive me. ;-)
Sandy, you know that I respect you and admire your work but in this case I unfortunately cannot support you.
Regards,
Harald
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Sandy - 06/03/2015 15:02:02
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| | Evening Blaze, Harald and anyone else interested,
The replies from both of you I received were exactly as I had already predicted.
However if there is no angular momentum present as I claimed in precession there cannot be any inertia in the system either.
Any mass in precession as I have repeatedly stated previously cannot be accelerated as it acts (or does not act) as though it is not in effect, present.
Hence the obvious loss of angular momentum, centrifugal force etc.
That said, I am sorry gentlemen that whilst you will no doubt disagree with my statements for some considerable time well into the future I must stand by the results of many experiments and disagree with what is in my mind the very limited, incorrect, but accepted, establishment view.
Regards,
Sandy
PS I will agree Blaze that a spinning gyroscope or flywheel when initially proceeding into precession will drop as stated in textbooks but only until the bottom of the first nutation bucket is reached.
From then on we have what you call steady state precession.
Is there any other kind?
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Harry K. - 06/03/2015 17:34:45
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| | Hi @all,
And again we go round in circles. Back to beginning!
Thus it makes no sense for further discussions, at least for me. Everyone may think or believe as anyone please. Time will tell or just even not. Never mind.
Regardsd,
Harald
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Nitro - 06/03/2015 17:37:07
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| | Oh Dear!,
This is of necessity long but it involves no maths, no experiments and, IF YOU CAN GET YOU FINGERS OUT OF YOUR ARSES AND READ THIS CAREFULLY AND IN FULL, you will understand why inertia and other effects disappear in precession. Sorry to swear but you guys are BLOODY EXASPERATING!
I should not put this simple explanation in the public domain but if I don’t I will be driven mad by you all
Sandy, not you, as you must be as tired as I am of trying to get the blind to see. (That you feel obliged to spare us all” from a couple of other issues is sad – those issues may give our brains a change.) However, I feel the need to keep banging on for god (or Farage, or Salmon, or Newton or whoever is in charge these days) knows what reason. So I’ll give it one more go.
You will all, surely, have noticed my going on about “NITRO’S FIRST LAW”. This is because understanding the implications of NITRO’s FIRST LAW is fundamental to understanding why the effects of (NOTE:- “effects” of) acceleration/mass/inertia/deceleration on precessing mass to all intents and purposes disappear.
This defies the understanding of many many people, some of them quite clever. Indeed, it seems that those better trained in the science of physics and maths have an off switch (just under their right ear) fitted, which makes them less able to get their heads around the simple implications of NITRO’S FIRST LAW. Despite using different ways to explain why some of the more outrageous anomalies, occurring in a precessing mass, happen, I have been unsuccessful.
I am clearly not a good teacher and I may, despite breaking down the ways that mass/acceleration/inertia “effects” seem to vanish, to help you guys understand, have fallen into the common teaching trap of assuming that because I easily “get it” others must surely also “get it”. So, let us repeat the first law again:- A gyro will precess EVERY force applied to change its axial angle NOT JUST THE FORCES YOU’VE THOUGHT OF. Now let us see how this makes infinite acceleration/deceleration, disappearing mass, and so many other outrageous gyrodynamic effects, happen...............
YOU GUYS DON’T DESERVE ME BUT YOU DO WANT TO UNDERSTAND - DON’T YOU? THEN BLOODY WELL BUCKLE UP AND KEEP CONCENTRATING!!!
NOTA BENE:- “NOT JUST THE FORCES YOU’VE THOUGHT OF”.........and NB also:- the use of the word force – means force, not energy .
Let’s start by looking at a “*perfect and frictionless” overhung gyro prior to its release into precession. Upon release, gravity becomes an applied force trying to change its axial angle so the gyro does its gyro thing and precesses that force into a movement 90 degrees from the applied force. Off it toddles on its merry way around its pivot.
All well and good so far? Well, actually no!
Because upon its release its movement around the pivot involves the acceleration of its mass there must be a concomitant inertia to that mass acceleration. AND there, abso-bloody-lutely IS inertia. That inertia has the effect of a rearward force, equal to the inertia, acting in the opposite direction to the gyro’s motion around the pivot. READ THAT AGAIN!
Apply NITRO’S FIRST LAW and guess what? Yes, you’ve got it! (at bloody last!) The inertia’s rearward force effect is also precessed 90 degrees into a downward force effect equal to the inertia. That downward force effect is, in turn, also precessed into a forward force effect equal to the inertia ELIMINATING IT’S EFFECT!!!
HAVE YOU SODDING WELL GOT IT YET. A gyro precesses EVERY force!!!!
What the precession of all the inertial forces (NOT JUST THE GRAVITY FORCES YOU LAZILY THOUGHT OF) involved means is that the effect of every inertial force (and that includes centrifugal force in this example) has been effectively cancelled out. This leaves just the effect of the force of gravity causing precession. AND with the disappearance of the EFFECT of inertia, magically, the gyro can go into precessional motion and be stopped INSTANTLY by the application or removal of the force (gravity in this case) precessing it!
HAVE YOU BLOODY WELL GOT IT YET?
JEEZ I HOPE SO!
Wake up you shower in the back! And don’t waste my time any more until you have read and grasped all the implications of all of the above. If you don’t “get it” now, you are beyond my help. If you do “get it” at last, then a thank-you would not go amiss.
Kind regards
NM
*not possible, I know but, as with understanding an Op. Amp., (you brilliant students have “got” linear amplifiers, haven’t you?) it’s function is easier to follow using a theoretically perfect example.
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Harry K. - 06/03/2015 18:49:06
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| | Beside your boorish character you also demonstrated that you do not have any clue about physics. Really embarrassing...
Have fun! :-)
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Nitro - 06/03/2015 19:00:25
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| | Hiya Harry,
Did I just hear your switch click off. Your loss.
NM
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Harry K. - 06/03/2015 19:45:52
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| | Nitro,
I shouldn't wonder if you hear strange sounds. Do you see also pictures with that or do you have other hallucinations? Maybe this is pathologic and you require medical care? Better ask your doctor! :-)
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Blaze - 06/03/2015 22:53:25
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| | Gentlemen, gentlemen, please. Let's be civil. People will believe what they want, whatever that may be. Personal attacks won't change that and certainly won't help to solve the topic of this forum.
Blaze
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Blaze - 06/03/2015 23:37:33
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| | Hi Sandy. Thanks for your comments.
"I will agree Blaze that a spinning gyroscope or flywheel when initially proceeding into precession will drop as stated in textbooks but only until the bottom of the first nutation bucket is reached."
Ok, so that drop or rise also happens when the input force (gravity or extra weight added or removal of some weight) is suddenly changed to a gyro that is precessing at steady state. The gyro initially precessing at steady state will in fact move higher and slow down its precession speed when the some (or all) of the input force is removed and will move lower and speed up when extra input force is applied (for a freewheeling hub, not mechanically driven). It still goes through the same sort of curve as when it is started from zero. If the change in speed were instantaneous there would be no reason for the gyro to move up or down.
The gyro moves up or down with a changing input force, AND takes a measurable time to make that change in height. The speed does not instantaneously change from one precession speed to the new precession speed before or after the gyro curves higher or lower. The change from one precession speed to the new precession speed occurs gradually during the entire change in height of the gyro. For at least gravity powered systems, the potential energy is changed to kinetic energy with an increase in input force and the kinetic energy is changed into potential energy with a decrease in input force. The gyro acts in a similar way for powered hub systems as well.
regards,
Blaze
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Nitro - 08/03/2015 11:26:42
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| | For Blaze and Harry,
A demonstration of missing inertia by Laithwaite for you. It is quite near the beginning of this video so you wont have to suffer long!
https://www.youtube.com/watch?v=QiTdJOS467c&list=PLoqW1tDux5_XVlHsdXdv5JMOrJOSKCKm4&index=2
Happy viewing,
NM
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Harry K. - 12/03/2015 17:14:52
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| | Hi Blaze,
Now you should have my correct email address. I just checked it but I did not find an email from you.
Regards,
Harald
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Blaze - 12/03/2015 18:54:11
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| | Hi Harald. That is the email I used. I resent the email. Hopefully this time you will get it. If not I will send it from another email account.
cheers,
Blaze
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Glenn Hawkins - 19/03/2015 15:36:20
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| | Look at this as it is related tho the argument.
http://gyroscopes.org/forum/questions.asp?id=2840
The forth post down 19/03/2015 15:20:37
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