Excellent! I have searched so many sites, videos etc. In this inflation of information World, you are the only one explaining in real physicist way (conservation of momentum), not by relying on shortcuts of right angle rules, conservation of angular momentum bla bla. Thanks for your great effort.
May I share the few sentences my elderly college physics professor used to solve this mystery for me ? 1) imagine a fictional, paper-thin-but-very-strong-and-stiff, weight-less disk that's 24 inches in diameter. It has a perpendicular axle thru its center (pitch axis). 2) imagine a white cue ball from a billiard table with some weight and mass ... magically attached somehow so that its spherical center is co-incident with the imaginary circle that is the outer edge of the disc (like an electron on its circular orbit). 3) Holding the ends axle at arms' length from your body; the plane of the disc is perpendicular to your body AND the floor. 4) With the disc spinning slowly, if its TOP edge rolls AWAY from you, its BOTTOM edge will come TOWARDS you: the cue ball comes towards you at the bottom and goes AWAY from you as it passes over the top. 5) If you look DOWN on the disk while holding it at arms length (hard on the neck), the disk will look like a line segment perpendicular to your body with one end close to you and the other end away from you. While looking down, as the cue ball orbits the disc, when it comes UP, it will appear to move to the END of the segment closest to your body. When the cue ball is at the TOP of the disk, looking down, it will look like it's in the MIDDLE of the line segment. 6) If - at the VERY instant the cue ball is going OVER the top - you rotate the disk's plane about a vertical axis thru the center of the cue ball (a YAW axis) ... say 30 degrees counter-clockwise ... while looking down, the line segment will look like you have rotated it counter-clockwise. BUT that cue ball has some weight and inertia ! and it does NOT want to suddenly change its path 30 degrees to the left to "stay on the disc" so the cue ball ends up "knocking that disc over" because now the plane is no longer aligned with the cue ball's direction of travel ... the plane is now "in the cue ball's way" and it gets "pushed over." That's why, when you're holding a spinning bicycle wheel at arms length, and try to pivot (yaw) it about its vertical axis some counter-clockwise amount, the wheel instead tries to "flop over" (roll) to the right.
+Jeffrey Hutchison I like this intuitive explanation. One thing, shouldn't line 5(b) read: "While looking down, as the cue ball orbits the disc, when it comes UP, it will appear to move to the END of the segment _furtherest_ to your body ? "
if you've got a 12 inch long neck and were able to extend it - like a snapping turtle - and then look DOWN at the edge of the rotating disc - which you're holding so that the plane of the disc is both perpendicular to your chest (while you're standing) and to the floor, then, if the disc is rotating so the edge closest your belly is coming up and the edge farthest is going down, the ball - when it's at the bottom of the disc - will appear to be in the middle of a line segment - what the edge of the disc looks like when you're looking DOWN at it. As the disc rotates, the ball moves FROM the CENTER of the "line segment" and towards your body as it rotates "up" the disc towards your chin, and then away as it passes over the the top of the disc and then descends along the circumference on the far edge. Of all the graphics and visuals which try to present WHY gyroscopes react as they do, I find the "weightless, thin disc with a single cue ball on its edge" to present the best mental model for explaining WHY a bicycle wheel wants to "flop over sideways" when you hold it at arms' length and impart a "yaw" input to the wheel's axle.
The more eight-cylinder, double-acting words you pile upon increasingly unwieldy syntax, (parentheses), CAPS - dashes - and "quote-marks", the harder for the reader to construct a mental image. A lot of people are still trying to struggle with the video.
hi, Leo ... thanks for your comment ! regarding line 5: 1) the disc is perpendicular to your body AND the floor (if it was a dirty bicycle rim, it'd create a dirty, black vertical line on your shirt from your belt line to your collar); 2) if you're standing to the RIGHT of the person-holding-the disc and looking at the center of the disc, it would appear to be spinning "clockwise" - thus the "cue ball" goes "up", close to the disc-holder's belly and then "away" from the disc-holder's chin as it rotates up to and beyond the 12 o'clock location. ... again, thanks for your comment. If you've found an animation that depicts a SINGLE mass element attached to the edge of a thin disc, please share the URL !
This is the single best explanation of gyroscope physics I have been able to find on the internet. Breaking down the point-mass trajectories into vectors has finally allowed me to understand precession the way I want to. One thing I would like to have seen is a vector representation of the linear downforce of gravity that creates the x-axis torque described. It's not really necessary, but it would give a basis for comparison (how much downforce translates to how much precession)
Excellent video! I think that explanation is clear enough to explain the stability without external forces applied. THings are going more counter intuitive when transverse torque is applied. In my view, the "tubes" provides a rigorous way to explain, but not clear enough. I suggest to consider the problem in a slight different way: - At a given time, reduce the spinning ring to a bar, rotating around the axis, with masses at each ends, corresponding to a "trench" of the wheel. On one mass, there is a force upward oriented and on the other the same force but downward oriented, making the wheel spinning. -Suppose a twist is given horizontally to the whole system. Now the masses will still see the upward and downward forces, as before, but furthermore, each of them will see a lateral forces, rightward on one side and leftward on the other. These further forces will act in a perpendicular plane woith respect to the plane containing up and down force (making the wheel spinning). - So to understand the resulting reaction induced by horizontal twist, it suffices to consider the resulting forces from the two existing in each masses . This resulting forces explains the movement resulting from the horizontal twist applied on our "elementary trench" of the spinning wheel. To obtain the global phenomena, we have to integrate this mehcanism to the whole wheel, which is a hot mathematical story, but which does not modify fundamentally the reasoning. Hughes explained the precession through this approach, in 1945, when working in SperryCo. Hope tyhis help! F2 fms7259.e-monsite.com/
Or at least Z's rotation making its own contribution against gravity. You can almost see the green ball mass naturally seeking to move downward behind the X Axis and upward in front of the X Axis. I think what is so counter-intuitive is that you don't consider the tangent, sideways momentum of a point on a moving wheel. Super helpful video!
In a very crude way of explaining, it's kind of like this: You apply a force to try to tilt the gyro. But because the mass is rotating, it's as if the reactive force "waits", or doesn't express itself until the mass has moved to a new (rotated) location. In essence, re-acting at a point different than where it was applied.
How about this: you can account for the spinning disc's forces by decomposing them in their x and y components. Their Vectorial product will generate a perpendicular force to those components. Now, if you apply a force to the rig, all you have to do is to perform a vectorial product of the previous force and the force you are applying, and the resultant shows how the gyro's precess.
your explanation and conclusion are brilliant ... for the love of physics, this would apply best for teaching, because it is the most honest geometrical and mechanical visualisation you could have, instead of hiding behind math
Thanks for the informative video, it seems to me we experience this gyroscopic effect in many aspects of our daily lives, for example; riding a bicycle, the faster you go the less balance input you need or as I did yesterday, I picked up a spinning hard-drive and it's resistance to changing the plain it was in was quite noticeable, I also recently used a large handheld grinder with a heavy spinning disk that also demonstrated the same properties as any other revolving disk. Infact we live on a large'ish revolving planet, I know that the earth wobbles a little but without this spin... well you get the idea. This gyroscopic effect seems fundamental to our very existence and without it there would be chaos, the galaxy is also revolving after all.
I'm not quite at the level understanding I want to be, but this video helped put me in the right direction. And I don't think your voice is boring at all!
this explanation is exactly understandable. And has not used abstract definition in physics and instead of it, he use a definition that is directly related to mass, inertia and mechanics of particle. thank you so much good job
I was watching a lot of explanations of the precession - you finally helped me get an intuitive understanding... Thank you!!! (Especially this is very important in the quantum world - now I can move on...)
I'm wondering if you could help with suggesting the correct angle offset and rotation between to gyro (used for stabilising an object) but want to cancel the effect of precession. Thanks.
Going into the minute detail like this is very informative. But I think the following is also very informative: The angular momentum of the gyroscope is a vector. It has magnitude L and direction n̂. Here n̂ is the unit vector along the axis of the gyroscope. It turns out that the torque T is just: T = d/dt( Ln̂ ) T = L d/dt( n̂ ) So although the magnitude L never changes, torque is generated by virtue of the fact that the unit vector along the axis of the gyroscope, is changing with time. Note that T is also a vector. I think the simplicity of the bottom equation speaks volumes about the cool physics!
I believe the whole thing with gyros is this: the mass never changes or otherwise we would be flying already with any gyro. the case is that the mass of the gyro changes so its located differently , how? yes, the ether around it does that
exelent explanation, after this video i could actually understand the forces acting. An excelent practical demonstration of this video is the experiment with the bycicle wheel rotating with one side of it axis suspended by a rope.
1. Movement one -- The hands, as the horizontal axis of the first torque movement, tip the bat "head" towards you (front), then quickly torque the bat directly away from you, reversing bat's direction which moves bat head behind the batter. (the force provided by the batter's hands start the bat head in this direction, but once the inertia is established, no additional force is provided by hands). As the bat head arcs with 1st movement, the 2nd movement is added. 2. Movement two - The body/to
I'm glad I have had to work with force vectors, or I wouldn't have understood any of this. That said, it WAS extremely useful for clearing up the bits I didn't understand! Liked.
Very nicely done. Thanks for the mechanical force vector analysis thought experiment idea and explanation. Very intuitive and understandable. Best I've seen. Thx.
I am getting that the vertical spin torque differential with a perfect horizontal , once washed through a transition matrix is .985, irrespective of mass, diameter and rotation. Also all my bicycles are busted. Makes sense ?
As for the torque force dependence on G. If my gyro weights 3 tons, and rotates at 3000 rpm around a 5 feet radius, some measurements could be different. But on the moon or elsewhere, Is their an equivalence relation in the lower moments ?
Interesting. Liked the parts that used the vectors. I've fooled with gyroscopes myself from time to time. Like the set up where there are two gyros in the same inertial frame but with their rotation in equal but opposite direction using the right hand rule. Then you vary one of the gyro's rotational velocity, either greater than its previous velocity or lesser. The inertial frame, if its on a frictional or one that is nearly so (a raft floating on water in a bathtub say)will spin or pull to one side or the other. I understand that some orbital satellites use something similar.
Sorry I'm a duffer when it comes to math but when you resolve the reactive forces and the all point outwards, what force is maintaining the spin of the wheel?
Beautiful presentation Sir! The idea of modeling segments of a tube with interior masses ( the ball-bearings) then plotting force (velocity) vectors is brilliant! As a teacher, I feel your explanation could be improved with two simple changes: 1- Prepare a concise, well-edited, pre-written speech to prevent saying "uh" so much. 2- Show the complete set of vectors from each side simultaneously in four separate windows as they impinge upon the tubes. Repeat 4X. Best Wishes, Thanks again!
Thank you for this. This phenomena has been driving whacko ;-) Simplified question? The forces move/act/react within the tubes, the balls cause straight forward & an outwardly pulling force simultaneously causing the (pitch or yaw?) to rotate the axis? Is that correct? Thank you again and look forward to your response. Dave
Awesome video presentation! I loved it. This really helps me in my slow but growing understanding for how a helicopter moves by tilting the "swash-plate" inducing "cyclic-pitch" into the rotors. What I still cannot fully understand however is the effect of precession, the 90 degrees of "lag" in the pitch change effect, versus the torque "steer" reaction moment about the rotors spinning axis of rotation. Why the 90 degrees offset? mrc109
Nice. I've always wondered why that motion happens at all, and also how precession occurs ('Is it a continuous process; or does it "wobble" its way around by nutation?'). Thanks to your video I now understand. Sincerely MarrusQ
1. The deflection shown only applies when the rotational displacement occurs, not when it is in a steady state. So any "out of balance" forces will only apply as the gyroscope shifts, for brief periods of time. 2. When the gyro wobbles, the forces would oscillate in a counter acting manor. Again, acting as you have shown both proportional to and during the rotational displacement. However, those forces should balance out. That said, I appreciate the video and your work. Just wanted to hopefully get that info out and see if you had any thoughts on it.
It seems to me that the desire to precess is manifest in the inter-atomic field geometry, just like any magnet. When coherent spin force is applied to the flywheel, a strong centripetal field geometry (dielectric acceleration) is created in conjunction with the obvious centrifugal force. A dielectric plane of inertia is concentrated, therefore changing the flywheels magnitude. Gravity (weight) is dependent, among other things, upon magnitude. A precessive force that is counter-rotation, is additive force and motion away from the centripetal dielectric acceleration (force dissipation null point) which can also be described as anti-gravity. I believe that this phenomenon is entirely field based. A very strange field geometry is manifest in any matter when it is spun. It is truly a real head wrecker. I cant though, work out whether a strange mono-pole is created or whether it is a weird compressed di-pole situation, similar to a permanent magnet. The pressure meditations certainly behave the same. Awesome thought experiment though, cheers.
@alextee07 you are correct that the red vectors would change as well as the green, but if I'm not mistaken, they would complement the vector change of the green vectors, not conflict with it. The example is simpler if you only have to think about the three dimensional effects of two vectors rather than four.
Continued#2 2. Movement two - The body/torso serves as the vertical axis of the second torque movement. (imagine a stake driven into the ground,through the head and crotch of batter). The right handed batter's body rotates in a counter clockwise motion. Question: Are any "interesting" gyroscopic forces in play as these two movements are combined -- which could result in faster and/or more powerful bat movement? Thanks in advance, G
This is a great video! I just have a few questions: How can you be sure that the magnitude of the balls velocity vector is the same before and after the balls leave the tubes? Also how can you be sure that you can tilt the apparatus any significant amount before a torque prevents you from pushing it farther? Finally, so do all gyroscopes nutate, or rather do they just reach an equilibrium state where they neither tip down or up?
is there a multi directional gyroscope and if there is do they behave in the same way as a conventional one? in the film Event Horizon, during the last 20 minutes there is a section where some of the crew fight it out around a death gyroscope. this gyroscope is a bit different. Would it ever be possible to create a gyroscope or something like it that can travel in a multi directional way at the same time? Is it anti-gravity or is it simply the flow of air as it passes over and through the spinning disc that creates its lift? if the disc was to spin in the opposite direction would the gyroscope behave in the same way? would this be a good test to either refute or backup the claim that gyroscopes have an effect much like anti-gravity?
Is it that, moving objects like to continue in a straight line and are being prevented from flying off so the energy is pulling them outwards which causes the downwards gravity to act equal on both sides because if one side went down, as its spinning it would climb a slope and pull itself level. with gravity on oppsite side. Hope you understand what i'm saying here.
I have a question though, Im doing a CFD analysis on helicopter blades. Ive been struggling to understand the principles gyroscopic precession. Why question is if to say that my blades did not have a mass or inertia, will this precession still exist? I can find a connection the connection...! //Chris
I imagine that the particles have opposite charge and that they are pushing and pulling at a mutual harmonic which creates a type of perpetual motion with one particle not allowing the other to fly out of the "system", a type of alternating current if you like. I would love to hear your thoughts
At 4:25, why does the torque about the x-axis simulate gravity? Isn't the torque in one direction being cancelled out by equal and opposite torque from the other side of the gyroscope?
Another way to look at the gyro is to imagine the wheel as a cross with elements at 4 points on a clock, 6, 9, 12, and 3 o'clock, with 12 on top of course. 12 thru the center vertically to 6 is the unmoving y axis, 9 thru the center to 3 the x axis and the rotational axis is z. Twisting the rotational (z) axis is said to be about an axis, x or y when it rotates the plane of the spinning gyro around that axis. So holding the rotational z axis at arms length, a twist or rotation of our hands is about the x axis if we rotate our hands counter-clockwise or clockwise. If we push-pull the rotation is about the vertical y axis either clockwise or counter when viewed from above the spinning wheel. We may rotate the wheel from 12 to 3 away from us or 12 to 9 towards us -- as we state a convention where the 9 o'clock is closest to our body. So holding our hands straight out form our body, the wheel's plane is normal (at right angles) to our body and the floor. Let's say we spin the wheel from 12 to 3 o'clock away from us. Then, with the wheel spinning, we twist the axle clockwise looking straight out, so the plane of the wheel attempts to rotate around the x axis -- the top or 12 o'clock being impelled to the right. What happens to the cross elements if we slow the action down in our mind? The 9 o'clock element which was nearest our body converges on and to the right of 12 on top of the wheel -- towards the y axis and to the right, thus making a curved rightward path -- or attempts to. We are saying we are trying to make the wheel's elements follow this path by our force on the axle. The former 12 o'clock element will try to converge on 3 o'clock making a path that has to twist the spoked element clockwise from our point of view (looking outwards) -- but whose path-target does not diverge from where it would have gone if the wheel's axle was not twisted. It is still impelled to go directly to where the 3 o'clock was when you started twisting the axle. We disregard the rigidity of our grip on the axle and imagine that the axle is free to move i.e to rotate around any other axis in any direction that we are not impelling it to move by the force we are putting on the axle. In other words, since we are constraining movement in the direction of applied force it either moves against our push or away. It's reaction due to inertia would be to move against the push, as that is its natural force. At the other axis in this case the Y it is free to move since it is not constrained. Thus if there is a rotational force around Y axis it must move about that axis. The forces around the Z axis are rotational inertia. The forces about the X axis are induced by our hands. The forces about the Y axis are induced by the translation of the force about the X axis to the Y axis given the imparted force in the rotating elements. These elements push back against the push induced by our hands, and around the Y axis. The upward moving element going from 9 to 12 exerts a force counter to its presumed or impelled curve path, by Newton's first law and third law. Since the wheel is free to move around the Y axis, as it is by our statement not constrained otherwise, this reactive force must make it move around this axis. If the wheel is spinning rapidly this force is considerable and may be much larger than our force impelling it to twist around the X axis. The wheel's elements have considerable inertia at high speed. The curved path which we attempt to induce by twisting the axle clockwise around the X axis is an impelled twist to the right. This path appears to be a clockwise curve when viewed from the top in this case, so the wheel's movement in inertial reaction to this force will be clockwise around the Y axis. We have in effect induced a detour in the path of the rim by pushing right on the top. If our eye follows the path from 9 to 12 from above we can clearly see its curvature to the right. The wheel therefore it movement not being constrained in this direction must follow the curved path and twist to our right. If we imagine we are pushing on a frame on the rim of the wheel, there would have to be an inertial resistance to our push due to the rim's rotational inertia -- its force in the direction of spin. There is however no resistance at 90 degrees to our push -- which is the 'rotational direction' around the axis that is normal to our applied force vector. The Y axis is at 90 degrees to, or normal to the sideways vector of our leftwards push on the rim at 6 o'clock -- which is also rightward at 12 as it is a torque. In effect the Y axis in this case "wobbles" rotationally underneath our effective push on it, and twists away from us in the direction of the wheel's spin. The effect is if we look at the path "called for by the push on the rim elements of the wheel" is that they "attempt to get there" so to speak by moving against to the applied force. By this we mean that there is a twisting movement around an axis which is at right angles to the applied force vector. In this case the Y, or vertical axis. Imagine we are applying force at the rim of the gyro. If we look back against the spin direction along the rim 90 degree's lets say and follow the spin as it approaches the point of force on the rim... let's say we are pushing on 6 o'clock towards our left in the set up above described .. we imagine just the element of the the gyro spinning from 3 o'clock to 6. Thus the rim point which was at 3 approaches to the left of 6 or tries to. ---- If the gyro is free to rotate about the vertical or Y axis, then one way it can "get to" the leftward position that the force attempts to push it to, is to spin clockwise around the vertical Y axis when viewed from the top. In other words "in the direction of spin" the gyro reorients itself in order for its rim elements to travel in line with, or in the same direction as the force applied. The rim at the point of applied force remains stationary or tries to and the point at 90 degrees to it moves such that the spinning rim elements try to travel toward the direction we are attempting to push the rim.
+Eric Charters Great science Eric. I admit a bit dangerous. Here is my 2 cent question : You do the simple rope holding a sniping wheel by the left or right of the shaft. You put a scale on the end of the rope. You got your fast spinning wheel and your horizontal shaft. Then you put 10 grams at the other end of the shaft. Then 20, then check the angle. Then what's the math ? Thanks for your differential topology experiment. I will keep at it.
simple simple.. total weight on rope is equal to gyro plus weight.. torque arm around the support rope is gyro wt times A-dist to gyro plane.. let's say clockwise.. then at end of shaft torque arm is clockwise of applied wt times 2A dist to end of shaft Obviously upward counterclockwise torque of gyro equals wt of gyro and applied wt until it doesn't anymore. soooo the math of the gyroscopic righting force is a tad more complex.. www.real-world-physics-problems.com/gyroscope-physics.html
Yeah....I was totally just thinking that it was what you said it is. So obvious right? And what you said about the x axis, hit the nail right on the head. Now my wife will have to let me continue building my antigrav Pontiac. EXCELSIOR !
As a graphic communication guy, i really like it. You seem to understand the forces involved. Do you think you could apply your understanding to a movement the human body makes when performing a type of high level baseball swing? Basically, the two movements I'm trying to understand are torque/rotational and are positioned in a way which is similar to "right angle gears". Consider the Batter to be facing you. 1. Movement one -- The hands, as the horizontal axis of the first torque movement,
the gyro has a mechanical transfer of movement in the bearing (armature to stator). gravity pulls down so there is more pressure on the top of the axel. if u support the axel from one side then the pressure is higher on that side friction is higher on that side transfering mechanical movement making a precession
Excellent! I have searched so many sites, videos etc. In this inflation of information World, you are the only one explaining in real physicist way (conservation of momentum), not by relying on shortcuts of right angle rules, conservation of angular momentum bla bla. Thanks for your great effort.
May I share the few sentences my elderly college physics professor used to solve this mystery for me ?
1) imagine a fictional, paper-thin-but-very-strong-and-stiff, weight-less disk that's 24 inches in diameter. It has a perpendicular axle thru its center (pitch axis).
2) imagine a white cue ball from a billiard table with some weight and mass ... magically attached somehow so that its spherical center is co-incident with the imaginary circle that is the outer edge of the disc (like an electron on its circular orbit).
3) Holding the ends axle at arms' length from your body; the plane of the disc is perpendicular to your body AND the floor.
4) With the disc spinning slowly, if its TOP edge rolls AWAY from you, its BOTTOM edge will come TOWARDS you: the cue ball comes towards you at the bottom and goes AWAY from you as it passes over the top.
5) If you look DOWN on the disk while holding it at arms length (hard on the neck), the disk will look like a line segment perpendicular to your body with one end close to you and the other end away from you.
While looking down, as the cue ball orbits the disc, when it comes UP, it will appear to move to the END of the segment closest to your body.
When the cue ball is at the TOP of the disk, looking down, it will look like it's in the MIDDLE of the line segment.
6) If - at the VERY instant the cue ball is going OVER the top - you rotate the disk's plane about a vertical axis thru the center of the cue ball (a YAW axis) ... say 30 degrees counter-clockwise ... while looking down, the line segment will look like you have rotated it counter-clockwise.
BUT that cue ball has some weight and inertia ! and it does NOT want to suddenly change its path 30 degrees to the left to "stay on the disc" so the cue ball ends up "knocking that disc over" because now the plane is no longer aligned with the cue ball's direction of travel ... the plane is now "in the cue ball's way" and it gets "pushed over."
That's why, when you're holding a spinning bicycle wheel at arms length, and try to pivot (yaw) it about its vertical axis some counter-clockwise amount, the wheel instead tries to "flop over" (roll) to the right.
+Jeffrey Hutchison I like this intuitive explanation. One thing, shouldn't line 5(b) read: "While looking down, as the cue ball orbits the disc, when it comes UP, it will appear to move to the END of the segment _furtherest_ to your body ? "
if you've got a 12 inch long neck and were able to extend it - like a snapping turtle - and then look DOWN at the edge of the rotating disc - which you're holding so that the plane of the disc is both perpendicular to your chest (while you're standing) and to the floor, then, if the disc is rotating so the edge closest your belly is coming up and the edge farthest is going down, the ball - when it's at the bottom of the disc - will appear to be in the middle of a line segment - what the edge of the disc looks like when you're looking DOWN at it. As the disc rotates, the ball moves FROM the CENTER of the "line segment" and towards your body as it rotates "up" the disc towards your chin, and then away as it passes over the the top of the disc and then descends along the circumference on the far edge.
Of all the graphics and visuals which try to present WHY gyroscopes react as they do, I find the "weightless, thin disc with a single cue ball on its edge" to present the best mental model for explaining WHY a bicycle wheel wants to "flop over sideways" when you hold it at arms' length and impart a "yaw" input to the wheel's axle.
The more eight-cylinder, double-acting words you pile upon increasingly unwieldy syntax, (parentheses), CAPS - dashes - and "quote-marks", the harder for the reader to construct a mental image.
A lot of people are still trying to struggle with the video.
hi, Leo ... thanks for your comment ! regarding line 5:
1) the disc is perpendicular to your body AND the floor (if it was a dirty bicycle rim, it'd create a dirty, black vertical line on your shirt from your belt line to your collar);
2) if you're standing to the RIGHT of the person-holding-the disc and looking at the center of the disc, it would appear to be spinning "clockwise" - thus the "cue ball" goes "up", close to the disc-holder's belly and then "away" from the disc-holder's chin as it rotates up to and beyond the 12 o'clock location.
... again, thanks for your comment.
If you've found an animation that depicts a SINGLE mass element attached to the edge of a thin disc, please share the URL !
Jeffrey Hutchinson I was with you all the way to the last sentence. Is the plane of the wheel perpendicular or parallel to you?
This is the best explanation which actually made me understand how precession works.
Great explanation! You managed to explain it in 10 minutes better than my physics professor did in an hour.
This is the single best explanation of gyroscope physics I have been able to find on the internet. Breaking down the point-mass trajectories into vectors has finally allowed me to understand precession the way I want to. One thing I would like to have seen is a vector representation of the linear downforce of gravity that creates the x-axis torque described. It's not really necessary, but it would give a basis for comparison (how much downforce translates to how much precession)
I've watched this video many times now, it is the best I've seen for explaining precession. Thank you.
That explanation was simply fantastic! Now it does make sense for me! I've been trying to understand this for months
This is the first time I've encountered the concept of nutation. Thank you for the effective visualizations and clear explanation.
Very neat. I like the way you use the graphics animation to analyse the vectors in 3D. A clear and compelling explanation.
Appreciate the explanation behind the actions, that until now had not been explained adequately. Thank you.
The cleverest way I've ever seen to explain gyroscope! Very clear and very helpful!
Thanks!
Excellent demonstration, it helped me visualize the forces governing the mystery of gyroscopes. Thanks for all the effort.
Excellent video! I think that explanation is clear enough to explain the stability without external forces applied. THings are going more counter intuitive when transverse torque is applied. In my view, the "tubes" provides a rigorous way to explain, but not clear enough.
I suggest to consider the problem in a slight different way:
- At a given time, reduce the spinning ring to a bar, rotating around the axis, with masses at each ends, corresponding to a "trench" of the wheel. On one mass, there is a force upward oriented and on the other the same force but downward oriented, making the wheel spinning.
-Suppose a twist is given horizontally to the whole system. Now the masses will still see the upward and downward forces, as before, but furthermore, each of them will see a lateral forces, rightward on one side and leftward on the other. These further forces will act in a perpendicular plane woith respect to the plane containing up and down force (making the wheel spinning).
- So to understand the resulting reaction induced by horizontal twist, it suffices to consider the resulting forces from the two existing in each masses . This resulting forces explains the movement resulting from the horizontal twist applied on our "elementary trench" of the spinning wheel. To obtain the global phenomena, we have to integrate this mehcanism to the whole wheel, which is a hot mathematical story, but which does not modify fundamentally the reasoning.
Hughes explained the precession through this approach, in 1945, when working in SperryCo.
Hope tyhis help!
F2
fms7259.e-monsite.com/
I've researching everywhere, but this vid is the most accurate, and simple(for me) explanation of gyroscope. Thanks.
it was the best explanation video about the gyroscopes phenomena here in youte. Congratulations
this is the best explanation of gyroscope in the detail how it works, not only describing the behavior of the gyroscope.
Or at least Z's rotation making its own contribution against gravity. You can almost see the green ball mass naturally seeking to move downward behind the X Axis and upward in front of the X Axis. I think what is so counter-intuitive is that you don't consider the tangent, sideways momentum of a point on a moving wheel. Super helpful video!
In a very crude way of explaining, it's kind of like this: You apply a force to try to tilt the gyro. But because the mass is rotating, it's as if the reactive force "waits", or doesn't express itself until the mass has moved to a new (rotated) location. In essence, re-acting at a point different than where it was applied.
How about this: you can account for the spinning disc's forces by decomposing them in their x and y components. Their Vectorial product will generate a perpendicular force to those components. Now, if you apply a force to the rig, all you have to do is to perform a vectorial product of the previous force and the force you are applying, and the resultant shows how the gyro's precess.
Using vectors makes the explanation very intuitive. Basically, each part of the rotating wheel try to keep the same direction of circular motion.
one of the best tutorial ever seen on youtube.... Excellent work .....:)
your explanation and conclusion are brilliant ... for the love of physics, this would apply best for teaching, because it is the most honest geometrical and mechanical visualisation you could have, instead of hiding behind math
Thanks for the informative video, it seems to me we experience this gyroscopic effect in many aspects of our daily lives, for example; riding a bicycle, the faster you go the less balance input you need or as I did yesterday, I picked up a spinning hard-drive and it's resistance to changing the plain it was in was quite noticeable, I also recently used a large handheld grinder with a heavy spinning disk that also demonstrated the same properties as any other revolving disk.
Infact we live on a large'ish revolving planet, I know that the earth wobbles a little but without this spin... well you get the idea. This gyroscopic effect seems fundamental to our very existence and without it there would be chaos, the galaxy is also revolving after all.
Best explanation I’ve seen so far! Thanks.
I'm not quite at the level understanding I want to be, but this video helped put me in the right direction. And I don't think your voice is boring at all!
this explanation is exactly understandable.
And has not used abstract definition in physics and instead of it, he use a definition that is directly related to mass, inertia and mechanics of particle.
thank you so much
good job
I like it. A nice approach with your "thought process"
Very well done. The best explanation I've seen yet.
I was watching a lot of explanations of the precession - you finally helped me get an intuitive understanding... Thank you!!!
(Especially this is very important in the quantum world - now I can move on...)
i thought of this myself but had no chance so far of trying that out.
you just earned your 600th sub ;D
This is exactly the answer I was looking for to this dilema, thank you very much.
Which simulation software package is used for this visualization and video?
Best explanation ever! Great work!
Thanks for a good explanation. This has helped me to understand gyroscopic precession in a different way.
I'm wondering if you could help with suggesting the correct angle offset and rotation between to gyro (used for stabilising an object) but want to cancel the effect of precession. Thanks.
Fantastic explanation and modelling!
Going into the minute detail like this is very informative. But I think the following is also very informative:
The angular momentum of the gyroscope is a vector. It has magnitude L and direction n̂. Here n̂ is the unit vector along the axis of the gyroscope.
It turns out that the torque T is just:
T = d/dt( Ln̂ )
T = L d/dt( n̂ )
So although the magnitude L never changes, torque is generated by virtue of the fact that the unit vector along the axis of the gyroscope, is changing with time. Note that T is also a vector.
I think the simplicity of the bottom equation speaks volumes about the cool physics!
Best explanation I’ve ever seen. Thank you. I will show this to my physics students.
jeffkosmo , In assuming you created these graphics, could you use the software to generate the other eyes perspective to give us a 3D video of this?
Excellent visualization, thanks! If you don't mind me asking what software did you use?
+Jurie Gryffenberg SolidWorks.
thanks, this has been unclear to me for years. thanks for finally solving the mystery.
I believe the whole thing with gyros is this: the mass never changes or otherwise we would be flying already with any gyro. the case is that the mass of the gyro changes so its located differently , how? yes, the ether around it does that
Very interesting - thank you! Question: why is it only two of the tube that create a torque?
exelent explanation, after this video i could actually understand the forces acting. An excelent practical demonstration of this video is the experiment with the bycicle wheel rotating with one side of it axis suspended by a rope.
Thanks for sharing, great work and very informative.
1. Movement one -- The hands, as the horizontal axis of the first torque movement, tip the bat "head" towards you (front), then quickly torque the bat directly away from you, reversing bat's direction which moves bat head behind the batter. (the force provided by the batter's hands start the bat head in this direction, but once the inertia is established, no additional force is provided by hands).
As the bat head arcs with 1st movement, the 2nd movement is added.
2. Movement two - The body/to
What program did you use? Can you 'play' around with the physics or is it just a drawing program?
excellent explanation....!!!! thanks a lot for making bit easy to understand...
Thanks! Really strong and clear explanation!
Animation is well done, but my question is: do you know where one can purchase a gyro WITH a display showing where it is pointing?
I'm glad I have had to work with force vectors, or I wouldn't have understood any of this. That said, it WAS extremely useful for clearing up the bits I didn't understand! Liked.
Very nicely done. Thanks for the mechanical force vector analysis thought experiment idea and explanation. Very intuitive and understandable. Best I've seen. Thx.
I am getting that the vertical spin torque differential with a perfect horizontal , once washed through a transition matrix is .985, irrespective of mass, diameter and rotation.
Also all my bicycles are busted. Makes sense ?
As for the torque force dependence on G. If my gyro weights 3 tons, and rotates at 3000 rpm around a 5 feet radius, some measurements could be different. But on the moon or elsewhere, Is their an equivalence relation in the lower moments ?
Thanks a lot man, this is really spoke to the way I understand things and it helped a lot.
This thought experiment really helped me to understand gyroscopes.
what soft ware are you using
Thanx, this video got me a bit further. An explination without gravity would help a lot too...
Very nice animation and explanation. Thank you
wooooooooow some lovely stuff!!!!!!!!!!! loved it!!!
Interesting. Liked the parts that used the vectors. I've fooled with gyroscopes myself from time to time. Like the set up where there are two gyros in the same inertial frame but with their rotation in equal but opposite direction using the right hand rule. Then you vary one of the gyro's rotational velocity, either greater than its previous velocity or lesser. The inertial frame, if its on a frictional or one that is nearly so (a raft floating on water in a bathtub say)will spin or pull to one side or the other. I understand that some orbital satellites use something similar.
How do you get the initial vector?
Sorry I'm a duffer when it comes to math but when you resolve the reactive forces and the all point outwards, what force is maintaining the spin of the wheel?
Inertia
That is pretty interesting!
This is fantastic.
Beautiful presentation Sir!
The idea of modeling segments of a tube with interior masses ( the ball-bearings) then plotting force (velocity) vectors is brilliant!
As a teacher, I feel your explanation could be improved with two simple changes:
1- Prepare a concise, well-edited, pre-written speech to prevent saying "uh" so much.
2- Show the complete set of vectors from each side simultaneously in four separate windows as they impinge upon the tubes. Repeat 4X.
Best Wishes, Thanks again!
Thank you for this. This phenomena has been driving whacko ;-)
Simplified question? The forces move/act/react within the tubes, the balls cause straight forward & an outwardly pulling force simultaneously causing the (pitch or yaw?) to rotate the axis? Is that correct? Thank you again and look forward to your response. Dave
Awesome video presentation! I loved it. This really helps me in my slow but growing understanding for how a helicopter moves by tilting the "swash-plate" inducing "cyclic-pitch" into the rotors. What I still cannot fully understand however is the effect of precession, the 90 degrees of "lag" in the pitch change effect, versus the torque "steer" reaction moment about the rotors spinning axis of rotation. Why the 90 degrees offset?
mrc109
Nice. I've always wondered why that motion happens at all, and also how precession occurs ('Is it a continuous process; or does it "wobble" its way around by nutation?'). Thanks to your video I now understand.
Sincerely
MarrusQ
Can u please upload the file with the 3D model? I still don't get how the vectors are lined up
Nice effort to explain gyroscopic motion...
This reminds me why I dropped my physics course, eventhough no confusing math formulas were involved
1. The deflection shown only applies when the rotational displacement occurs, not when it is in a steady state. So any "out of balance" forces will only apply as the gyroscope shifts, for brief periods of time. 2. When the gyro wobbles, the forces would oscillate in a counter acting manor. Again, acting as you have shown both proportional to and during the rotational displacement. However, those forces should balance out.
That said, I appreciate the video and your work. Just wanted to hopefully get that info out and see if you had any thoughts on it.
It seems to me that the desire to precess is manifest in the inter-atomic field geometry, just like any magnet. When coherent spin force is applied to the flywheel, a strong centripetal field geometry (dielectric acceleration) is created in conjunction with the obvious centrifugal force. A dielectric plane of inertia is concentrated, therefore changing the flywheels magnitude. Gravity (weight) is dependent, among other things, upon magnitude. A precessive force that is counter-rotation, is additive force and motion away from the centripetal dielectric acceleration (force dissipation null point) which can also be described as anti-gravity. I believe that this phenomenon is entirely field based. A very strange field geometry is manifest in any matter when it is spun. It is truly a real head wrecker. I cant though, work out whether a strange mono-pole is created or whether it is a weird compressed di-pole situation, similar to a permanent magnet. The pressure meditations certainly behave the same. Awesome thought experiment though, cheers.
Great work dude........the idea of using balls inside the tubes for simulating gyro effects was simply brilliant.....Though it needs more study.....
@alextee07 you are correct that the red vectors would change as well as the green, but if I'm not mistaken, they would complement the vector change of the green vectors, not conflict with it. The example is simpler if you only have to think about the three dimensional effects of two vectors rather than four.
Continued#2
2. Movement two - The body/torso serves as the vertical axis of the second torque movement. (imagine a stake driven into the ground,through the head and crotch of batter). The right handed batter's body rotates in a counter clockwise motion.
Question:
Are any "interesting" gyroscopic forces in play as these two movements are combined -- which could result in faster and/or more powerful bat movement?
Thanks in advance,
G
great visualization! thanks
This is a great video! I just have a few questions: How can you be sure that the magnitude of the balls velocity vector is the same before and after the balls leave the tubes? Also how can you be sure that you can tilt the apparatus any significant amount before a torque prevents you from pushing it farther? Finally, so do all gyroscopes nutate, or rather do they just reach an equilibrium state where they neither tip down or up?
is there a multi directional gyroscope and if there is do they behave in the same way as a conventional one?
in the film Event Horizon, during the last 20 minutes there is a section where some of the crew fight it out around a death gyroscope. this gyroscope is a bit different. Would it ever be possible to create a gyroscope or something like it that can travel in a multi directional way at the same time?
Is it anti-gravity or is it simply the flow of air as it passes over and through the spinning disc that creates its lift? if the disc was to spin in the opposite direction would the gyroscope behave in the same way? would this be a good test to either refute or backup the claim that gyroscopes have an effect much like anti-gravity?
I have a small query.
Shouldn't the net force vector should be final - initial and not the other way around. ( 6:05 )
This really helped me a lot!! although i do not think it can solve all of the problems about a gyro, but this is a good start!
Outstanding!
Nice job it really is clear to me now!
a very nice explanation sir ..this video helped a lot
that is an awesome analysis
Great work no doubt.
Very nice - Thanks.
Is it that, moving objects like to continue in a straight line and are being prevented from flying off so the energy is pulling them outwards which causes the downwards gravity to act equal on both sides because if one side went down, as its spinning it would climb a slope and pull itself level. with gravity on oppsite side. Hope you understand what i'm saying here.
Best explanation...
I have a question though, Im doing a CFD analysis on helicopter blades. Ive been struggling to understand the principles gyroscopic precession. Why question is if to say that my blades did not have a mass or inertia, will this precession still exist? I can find a connection the connection...!
//Chris
I imagine that the particles have opposite charge and that they are pushing and pulling at a mutual harmonic which creates a type of perpetual motion with one particle not allowing the other to fly out of the "system", a type of alternating current if you like. I would love to hear your thoughts
At 4:25, why does the torque about the x-axis simulate gravity? Isn't the torque in one direction being cancelled out by equal and opposite torque from the other side of the gyroscope?
Another way to look at the gyro is to imagine the wheel as a cross with elements at 4 points on a clock, 6, 9, 12, and 3 o'clock, with 12 on top of course. 12 thru the center vertically to 6 is the unmoving y axis, 9 thru the center to 3 the x axis and the rotational axis is z.
Twisting the rotational (z) axis is said to be about an axis, x or y when it rotates the plane of the spinning gyro around that axis. So holding the rotational z axis at arms length, a twist or rotation of our hands is about the x axis if we rotate our hands counter-clockwise or clockwise.
If we push-pull the rotation is about the vertical y axis either clockwise or counter when viewed from above the spinning wheel.
We may rotate the wheel from 12 to 3 away from us or 12 to 9 towards us -- as we state a convention where the 9 o'clock is closest to our body. So holding our hands straight out form our body, the wheel's plane is normal (at right angles) to our body and the floor. Let's say we spin the wheel from 12 to 3 o'clock away from us.
Then, with the wheel spinning, we twist the axle clockwise looking straight out, so the plane of the wheel attempts to rotate around the x axis -- the top or 12 o'clock being impelled to the right.
What happens to the cross elements if we slow the action down in our mind? The 9 o'clock element which was nearest our body converges on and to the right of 12 on top of the wheel -- towards the y axis and to the right, thus making a curved rightward path -- or attempts to. We are saying we are trying to make the wheel's elements follow this path by our force on the axle.
The former 12 o'clock element will try to converge on 3 o'clock making a path that has to twist the spoked element clockwise from our point of view (looking outwards) -- but whose path-target does not diverge from where it would have gone if the wheel's axle was not twisted. It is still impelled to go directly to where the 3 o'clock was when you started twisting the axle.
We disregard the rigidity of our grip on the axle and imagine that the axle is free to move i.e to rotate around any other axis in any direction that we are not impelling it to move by the force we are putting on the axle. In other words, since we are constraining movement in the direction of applied force it either moves against our push or away. It's reaction due to inertia would be to move against the push, as that is its natural force. At the other axis in this case the Y it is free to move since it is not constrained. Thus if there is a rotational force around Y axis it must move about that axis. The forces around the Z axis are rotational inertia. The forces about the X axis are induced by our hands. The forces about the Y axis are induced by the translation of the force about the X axis to the Y axis given the imparted force in the rotating elements. These elements push back against the push induced by our hands, and around the Y axis.
The upward moving element going from 9 to 12 exerts a force counter to its presumed or impelled curve path, by Newton's first law and third law. Since the wheel is free to move around the Y axis, as it is by our statement not constrained otherwise, this reactive force must make it move around this axis. If the wheel is spinning rapidly this force is considerable and may be much larger than our force impelling it to twist around the X axis. The wheel's elements have considerable inertia at high speed.
The curved path which we attempt to induce by twisting the axle clockwise around the X axis is an impelled twist to the right. This path appears to be a clockwise curve when viewed from the top in this case, so the wheel's movement in inertial reaction to this force will be clockwise around the Y axis. We have in effect induced a detour in the path of the rim by pushing right on the top. If our eye follows the path from 9 to 12 from above we can clearly see its curvature to the right. The wheel therefore it movement not being constrained in this direction must follow the curved path and twist to our right.
If we imagine we are pushing on a frame on the rim of the wheel, there would have to be an inertial resistance to our push due to the rim's rotational inertia -- its force in the direction of spin. There is however no resistance at 90 degrees to our push -- which is the 'rotational direction' around the axis that is normal to our applied force vector. The Y axis is at 90 degrees to, or normal to the sideways vector of our leftwards push on the rim at 6 o'clock -- which is also rightward at 12 as it is a torque. In effect the Y axis in this case "wobbles" rotationally underneath our effective push on it, and twists away from us in the direction of the wheel's spin.
The effect is if we look at the path "called for by the push on the rim elements of the wheel" is that they "attempt to get there" so to speak by moving against to the applied force. By this we mean that there is a twisting movement around an axis which is at right angles to the applied force vector. In this case the Y, or vertical axis.
Imagine we are applying force at the rim of the gyro. If we look back against the spin direction along the rim 90 degree's lets say and follow the spin as it approaches the point of force on the rim... let's say we are pushing on 6 o'clock towards our left in the set up above described .. we imagine just the element of the the gyro spinning from 3 o'clock to 6. Thus the rim point which was at 3 approaches to the left of 6 or tries to. ---- If the gyro is free to rotate about the vertical or Y axis, then one way it can "get to" the leftward position that the force attempts to push it to, is to spin clockwise around the vertical Y axis when viewed from the top. In other words "in the direction of spin" the gyro reorients itself in order for its rim elements to travel in line with, or in the same direction as the force applied. The rim at the point of applied force remains stationary or tries to and the point at 90 degrees to it moves such that the spinning rim elements try to travel toward the direction we are attempting to push the rim.
+Eric Charters Great science Eric. I admit a bit dangerous. Here is my 2 cent question : You do the simple rope holding a sniping wheel by the left or right of the shaft. You put a scale on the end of the rope. You got your fast spinning wheel and your horizontal shaft. Then you put 10 grams at the other end of the shaft. Then 20, then check the angle. Then what's the math ? Thanks for your differential topology experiment. I will keep at it.
simple simple.. total weight on rope is equal to gyro plus weight.. torque arm around the support rope is gyro wt times A-dist to gyro plane.. let's say clockwise.. then at end of shaft torque arm is clockwise of applied wt times 2A dist to end of shaft Obviously upward counterclockwise torque of gyro equals wt of gyro and applied wt until it doesn't anymore.
soooo the math of the gyroscopic righting force is a tad more complex..
www.real-world-physics-problems.com/gyroscope-physics.html
very good examples!
Yeah....I was totally just thinking that it was what you said it is. So obvious right? And what you said about the x axis, hit the nail right on the head. Now my wife will have to let me continue building my antigrav Pontiac. EXCELSIOR !
This video was great, thank you very much
Nice explanation for the mathematically challenged. It really does make sense!
As a graphic communication guy, i really like it. You seem to understand the forces involved. Do you think you could apply your understanding to a movement the human body makes when performing a type of high level baseball swing?
Basically, the two movements I'm trying to understand are torque/rotational and are positioned in a way which is similar to "right angle gears". Consider the Batter to be facing you.
1. Movement one -- The hands, as the horizontal axis of the first torque movement,
the gyro has a mechanical transfer of movement in the bearing (armature to stator). gravity pulls down so there is more pressure on the top of the axel. if u support the axel from one side then the pressure is higher on that side friction is higher on that side transfering mechanical movement making a precession
Very interesting and informative
Nice! I did not understand why the effect of gravity is a rotation on x. I ll watch it again.
So its about mass at a point being deflected as a result of being fixed around an axis. The reaction is what keeps it all in place?