Gyroscopic Action
- Thread starter mandrin
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First, I've got to say bbftx's post provided a great perspective, and was informative and useful.
Next..
If the forum's Intro was to be adhered to, then this sort of topic would best be addressed by a thread on "How best to teach (or describe) gyroscopic elements of the swing." ...not... "Was HK right or wrong about gyroscopic elements of the swing."
I think the OP came close but asserted right away there were errors etc.
Next..
If the forum's Intro was to be adhered to, then this sort of topic would best be addressed by a thread on "How best to teach (or describe) gyroscopic elements of the swing." ...not... "Was HK right or wrong about gyroscopic elements of the swing."
I think the OP came close but asserted right away there were errors etc.
mandrin
New
Bbftx, a lot of copy paste thinking taking place in your post but it appears that you have not read or simply not understood anything I said before. Therefore I will try to explain the obvious to you from a totally another angle.
A gyroscope is fundamentally a fast spinning flywheel, constant angular speed, having perfect symmetry around the spin axis. It is basically this feature, this perfect symmetry around an axis, which allows the truly fascinating but counter intuitive behavior of a gyroscope.
When considering a golf swing we have essentially a point mass, being accelerated from zero speed, for only a limited time, and only a during short arc, around an axis. Moreover, its mass distribution is completely and totally asymmetric re the center of rotation.
To compare a golf down swing to a gyroscope has no substance whatsover from any point of view - neither scientifically, mechanically, mathematically, geometrically, nor whatever way you wish to consider. Not even as a metaphor or allegorically.
The fast spinning flywheel, under stationary conditions, will exert no force whatsoever (except weight) on its axis. A fast twirling point mass however will generate a very large centrifugal force. It is essentially this centrifugal force which is at the origin of a restoring torque existing in the golf swing, definitely not some gyroscopic effect.
I have mentioned this fact on several occasions, and even analyzed it mathematically in another thread. It is the centrifugal force - truly the heart and soul of a golf swing - which is responsible for the existence of a restoring torque in a golf swing.
If you don’t agree with me, I would be delighted to hear your scientific arguments to support your opinion, preferably using mathematics to avoid the usual double talk, leading to one standard for HK and a totally different one for me. [V]
Give me something solid to bite on not just some ambigious sweet poetic reasoning. If you find some scientific justification for your opinion, than you will have truly introduced something totally new in science. I can’t wait to hear all about it.
The next TGM edition should eliminate any reference to gyroscopes. First of all, HK’s definition of gyroscope action itself is erroneous and additionally, even much more important - a golf swing bears no functional relationship whatsoever with a gyroscope.
quote:Originally posted by mandrin
...
When considering a golf swing we have essentially a point mass, being accelerated from zero speed, for only a limited time, and only a during short arc, around an axis. Moreover, its mass distribution is completely and totally asymmetric re the center of rotation.
To compare a golf down swing to a gyroscope has no substance whatsover from any point of view - neither scientifically, mechanically, mathematically, geometrically, nor whatever way you wish to consider. Not even as a metaphor or allegorically.
The fast spinning flywheel, under stationary conditions, will exert no force whatsoever (except weight) on its axis. A fast twirling point mass however will generate a very large centrifugal force. It is essentially this centrifugal force which is at the origin of a restoring torque existing in the golf swing, definitely not some gyroscopic effect.
I have mentioned this fact on several occasions, and even analyzed it mathematically in another thread. It is the centrifugal force - truly the heart and soul of a golf swing - which is responsible for the existence of a restoring torque in a golf swing.
...
The next TGM edition should eliminate any reference to gyroscopes. First of all, HK?s definition of gyroscope action itself is erroneous and additionally, even much more important - a golf swing bears no functional relationship whatsoever with a gyroscope.
mandrin:
I take it from the post above that Kelley's "whirling weight on a string" as an example of gyroscopic action is a poor one. Correct?
Would you agree with HK's assertion that "a golfclub swinging either On Plane or Off Plane, resists any attempt to change its plane"? And if you do agree with this assertion, what scientific example would YOU give for this principle if you had the opportunity to edit this entry in the glossary?
hiro
Burner
New
The problem with mandrin is that he cannot bring himself to be anything other than the definitive source of all matters scientific - even if it involves him taking matters from the contextual into the abstract in order to prove a point. His point being that Homer, in the golfing context in which he writes, is wrong whereas mandrin, in the abstract scientific arguments he submits, is always right.
Homer uses this partial description of the whole gyroscopic motion only in the context of the golf stroke and likens it to a club being swung on plane and vice versa.
The rest of the gyroscopic motion, in its full and non-golf related scientific sense, is irrelevant to Homers explanation of a golf swing and is thus redundant in this context.
mandrin on the other hand is not interested in anything other than debunking Homers explanations, on purely abstract terms, and has no interest in adding anything constructive to this golf forum.
His interest is in mischief making alone and nothing to do with golf, TGM or any related subject.
Can anyone quote any instance where mandrin has actually helped them with their golf swing in either a practical or purely theoretic sense?
No such question could be asked of Mr Kelley.
Homer uses this partial description of the whole gyroscopic motion only in the context of the golf stroke and likens it to a club being swung on plane and vice versa.
The rest of the gyroscopic motion, in its full and non-golf related scientific sense, is irrelevant to Homers explanation of a golf swing and is thus redundant in this context.
mandrin on the other hand is not interested in anything other than debunking Homers explanations, on purely abstract terms, and has no interest in adding anything constructive to this golf forum.
His interest is in mischief making alone and nothing to do with golf, TGM or any related subject.
Can anyone quote any instance where mandrin has actually helped them with their golf swing in either a practical or purely theoretic sense?
No such question could be asked of Mr Kelley.
bbftx
New
MAndrin,
When I was a young engineer, fresh out of MIT with A's in all of my engineering, math, fluids and physics courses, I went to work in the oil patch. I worked on production field facilities, joining a team of fun, smart, experienced engineers. One of my first assignments was to redesign a particular collection tank with which we were having problems. Part of my solution presented to the team included a beautiful mathematical analysis using Bernoulli's Equation to make some point about fluid flow in the outlet piping of this tank.
This produced a good chuckle amongst my colleagues, who said, "Wow, that's the first time I've seen Bernoulli's equation used here in Salt Creek field. Now, how is that going to keep the field hand from coming off his break, turning that valve when he's not supposed to, when the tank level is at X, and thereby collapsing the entire tank and creating one godawful mess?"
The math was correct, but had nothing to do with the actual solution for the problem at hand.
I have let most of my math muscles get pretty weak, as I don't particularly enjoy doing it and in the context of the golf swing, I think it's of limited value to telling me how to improve my performance. But, I certainly don't begrudge anybody that might get something out of that type of analysis. (i.e. you)
But, a "scientific" model does not necessarily require mathematics to be "scientific" or useful. Non-mathematical relationships can be a valid foundation for useful models in this world we live in.
I used to look for what was wrong in other people's models and ideas, instead of looking for what might be useful in those models. If you don't find some of Homer's little metaphors meaningful to you, that's fine . But don't begrudge someone else if they find some value or benefit in them. I like Homer's models of grip, hinge action, hip action, knee action and stroke types. He loses me on some of the other components, but that doesn't mean they're worthless. Other people may be able to find useful nuggets there, and I might too someday. And there are errors in the book here and there, but it doesn't make it a worthless model either.
And no, I don't read all your posts. Sorry, I'll try to catch up.
When I was a young engineer, fresh out of MIT with A's in all of my engineering, math, fluids and physics courses, I went to work in the oil patch. I worked on production field facilities, joining a team of fun, smart, experienced engineers. One of my first assignments was to redesign a particular collection tank with which we were having problems. Part of my solution presented to the team included a beautiful mathematical analysis using Bernoulli's Equation to make some point about fluid flow in the outlet piping of this tank.
This produced a good chuckle amongst my colleagues, who said, "Wow, that's the first time I've seen Bernoulli's equation used here in Salt Creek field. Now, how is that going to keep the field hand from coming off his break, turning that valve when he's not supposed to, when the tank level is at X, and thereby collapsing the entire tank and creating one godawful mess?"
The math was correct, but had nothing to do with the actual solution for the problem at hand.
I have let most of my math muscles get pretty weak, as I don't particularly enjoy doing it and in the context of the golf swing, I think it's of limited value to telling me how to improve my performance. But, I certainly don't begrudge anybody that might get something out of that type of analysis. (i.e. you)
But, a "scientific" model does not necessarily require mathematics to be "scientific" or useful. Non-mathematical relationships can be a valid foundation for useful models in this world we live in.
I used to look for what was wrong in other people's models and ideas, instead of looking for what might be useful in those models. If you don't find some of Homer's little metaphors meaningful to you, that's fine . But don't begrudge someone else if they find some value or benefit in them. I like Homer's models of grip, hinge action, hip action, knee action and stroke types. He loses me on some of the other components, but that doesn't mean they're worthless. Other people may be able to find useful nuggets there, and I might too someday. And there are errors in the book here and there, but it doesn't make it a worthless model either.
And no, I don't read all your posts. Sorry, I'll try to catch up.
Homer's work is supposed to be based on geometry and physics. As such, if there are errors of math or science, I believe they should be corrected. Hopefully the correct version will bring more clarity to what often can be befuddling text. This can be looked upon as an opportunity to improve something, not begrudge it.
bbftx,
Absolutely! I have read and own more golf books than I care to admit, and have studied and attempted an embarrassingly high number of different swing models. TGM, with the help of the various fora, is to me the best of the bunch and I plan to stick with it (at least until I can get a MORAD lesson
).However, having said that, if there is an error, I see no downside in acknowledging and correcting it. The dogmatic reluctance of many to question Homer's work leads to the "cult-like" perception of TGM, in my opinion.
hiro
mandrin
New
I take it from the post above that Kelley's "whirling weight on a string" as an example of gyroscopic action is a poor one. Correct?quote:Originally posted by hiroshiro
quote:Originally posted by mandrin
...
When considering a golf swing we have essentially a point mass, being accelerated from zero speed, for only a limited time, and only a during short arc, around an axis. Moreover, its mass distribution is completely and totally asymmetric re the center of rotation.
To compare a golf down swing to a gyroscope has no substance whatsover from any point of view - neither scientifically, mechanically, mathematically, geometrically, nor whatever way you wish to consider. Not even as a metaphor or allegorically.
The fast spinning flywheel, under stationary conditions, will exert no force whatsoever (except weight) on its axis. A fast twirling point mass however will generate a very large centrifugal force. It is essentially this centrifugal force which is at the origin of a restoring torque existing in the golf swing, definitely not some gyroscopic effect.
I have mentioned this fact on several occasions, and even analyzed it mathematically in another thread. It is the centrifugal force - truly the heart and soul of a golf swing - which is responsible for the existence of a restoring torque in a golf swing.
...
The next TGM edition should eliminate any reference to gyroscopes. First of all, HK?s definition of gyroscope action itself is erroneous and additionally, even much more important - a golf swing bears no functional relationship whatsoever with a gyroscope.
mandrin:
I take it from the post above that Kelley's "whirling weight on a string" as an example of gyroscopic action is a poor one. Correct?
Would you agree with HK's assertion that "a golfclub swinging either On Plane or Off Plane, resists any attempt to change its plane"? And if you do agree with this assertion, what scientific example would YOU give for this principle if you had the opportunity to edit this entry in the glossary?
hiro
Yes
Would you agree with HK's assertion that "a golfclub swinging either On Plane or Off Plane, resists any attempt to change its plane"?
Yes, but I would leave out ‘Off Plane’.
And if you do agree with this assertion, what scientific example would YOU give for this principle if you had the opportunity to edit this entry in the glossary?
The proper reference is to invoke centrifugal force. Objects rotating around an axis strive, due to this force, to move as far as possible from the axis. This occurs when the object is moving in a plane perpendicular to the axis of rotation. Any departure generates than a restoring force/torque.
Something defined along the lines above will definitely be closer to physical reality.
hiroshiro, I find it quite funny that I can without any problem invoke centrifugal force. Reason? Very simple. HK used it in TGM. On any other forum it would immediately provoke posts claiming that it is a complete hoax, does not exists, etc. [
]quote:Originally posted by mandrin
...
hiroshiro, I find it quite funny that I can without any problem invoke centrifugal force. Reason? Very simple. HK used it in TGM. On any other forum it would immediately provoke posts claiming that it is a complete hoax, does not exists, etc. [
Thank you for the reply.
I did note the numerous references to the fictitious force, but assumed that it was addressed here in the past and some sort of "cease fire" was in effect.
hiro
bbftx
New
mandrin,
I played golf this morning with a friend in the alternative energy biz. We had a good discussion about wind turbines. I learned a lot, including how gyroscopic behavior and gryoscopic mathematics are used to design multi-blade turbines. Now these aren't "gyroscopes" and they aren't "perfectly symmetric" about the spin axis obviously. Neither are the rotors on a gyrocopter for that matter. Yet, gyroscopic mathematics and behavior can be applied to great use in the design and operation of these devices.
[ In fact, among the wind farms here in Tejas are a type of turbine called teetered-rotor wind turbines. The rotors can be adjusted such that they aren't even perpendicular to the spin axis. They apparently exhibit some interesting "gyroscopically asymmetric" behavior.]
Perhaps, if you're openminded, you could take a look at some of the work in this area and look for similarities in your swing math and how these rotors behave? In particular, you might consider some of the gyroscopic instability and response of the rotor blades that can be observed at start-up on these turbines and how they are controlled. There are apparently similar mathematics at work, even in the first cycle of the rotors, that are analogous to a single-cycle golf swing. Specifically, I think you'll find similar "self-corrective actions" and mathematics between your "centrifugal golf swing engine" and the gyroscopic calcs on these asymmetric rotors. And I'm sure you'll find differences too. But maybe you can find something that will help your own math quest perhaps?
It's interesting to speculate that Kelley, being a technician in the aeronautics biz, might have seen these analogies at work between the golf swing and rotors and gyrocopters, ---- where "gyroscopic behavior" can be useful tools of analysis, even though none of these things are "gyroscopes" in a strict sense.
I played golf this morning with a friend in the alternative energy biz. We had a good discussion about wind turbines. I learned a lot, including how gyroscopic behavior and gryoscopic mathematics are used to design multi-blade turbines. Now these aren't "gyroscopes" and they aren't "perfectly symmetric" about the spin axis obviously. Neither are the rotors on a gyrocopter for that matter. Yet, gyroscopic mathematics and behavior can be applied to great use in the design and operation of these devices.
[ In fact, among the wind farms here in Tejas are a type of turbine called teetered-rotor wind turbines. The rotors can be adjusted such that they aren't even perpendicular to the spin axis. They apparently exhibit some interesting "gyroscopically asymmetric" behavior.]
Perhaps, if you're openminded, you could take a look at some of the work in this area and look for similarities in your swing math and how these rotors behave? In particular, you might consider some of the gyroscopic instability and response of the rotor blades that can be observed at start-up on these turbines and how they are controlled. There are apparently similar mathematics at work, even in the first cycle of the rotors, that are analogous to a single-cycle golf swing. Specifically, I think you'll find similar "self-corrective actions" and mathematics between your "centrifugal golf swing engine" and the gyroscopic calcs on these asymmetric rotors. And I'm sure you'll find differences too. But maybe you can find something that will help your own math quest perhaps?
It's interesting to speculate that Kelley, being a technician in the aeronautics biz, might have seen these analogies at work between the golf swing and rotors and gyrocopters, ---- where "gyroscopic behavior" can be useful tools of analysis, even though none of these things are "gyroscopes" in a strict sense.
mandrin
New
bbftx, interesting observations. Gyroscopes are indeed truly fascinating devices. So counter-intuitive in their behavior. Interesting though how much effort is put towards saving HK’s ideas.
I like to remind that gyroscope rotors by definition have to have a very high degree of symmetry otherwise very large forces will be generated and hence useless in gyroscopes.
To compare a golfswing starting from zero speed with lots of torque applied and existing for only a very restricted arc to a gyroscope is just too much. An elastic can be super stretched, but.......
Let’s just decide that we should compare apples with apples and hence the only appropriate way is to look at the issue by utilizing the faithful and obedient centrifugal force, explaining it all very clearly.
It is not a question of being open minded or not. It is a simply a matter of not starting to invent a science to suit me but rather have science objectively tell me what is out there.
I like to remind that gyroscope rotors by definition have to have a very high degree of symmetry otherwise very large forces will be generated and hence useless in gyroscopes.
To compare a golfswing starting from zero speed with lots of torque applied and existing for only a very restricted arc to a gyroscope is just too much. An elastic can be super stretched, but.......
Let’s just decide that we should compare apples with apples and hence the only appropriate way is to look at the issue by utilizing the faithful and obedient centrifugal force, explaining it all very clearly.
It is not a question of being open minded or not. It is a simply a matter of not starting to invent a science to suit me but rather have science objectively tell me what is out there.
bbftx
New
quote:Originally posted by mandrin
bbftx, interesting observations. Gyroscopes are indeed truly fascinating devices. So counter-intuitive in their behavior. Interesting though how much effort is put towards saving HK’s ideas.
I like to remind that gyroscope rotors by definition have to have a very high degree of symmetry otherwise very large forces will be generated and hence useless in gyroscopes.
To compare a golfswing starting from zero speed with lots of torque applied and existing for only a very restricted arc to a gyroscope is just too much. An elastic can be super stretched, but.......
Let’s just decide that we should compare apples with apples and hence the only appropriate way is to look at the issue by utilizing the faithful and obedient centrifugal force, explaining it all very clearly.
It is not a question of being open minded or not. It is a simply a matter of not starting to invent a science to suit me but rather have science objectively tell me what is out there.
mandrin,
I am not inventing new science. If you'd read my post carefully, you'd note that gyroscopic behavior is relevant to wind turbine START-UP (i.e. restricted to the first cycle, starting from zero velocity -- like a "restricted arc" golf swing). YOU can shut your eyes to RESPONSES to your childish challenges, but any scientifically honest person would examine the analogy a little more thoroughly before dismissing it out of hand.
You used the term "perfectly symmetric" to try to discount the metaphor of gyroscopic behavior of an asymmetric golf rotor system. When presented with asymmetric examples of real-world devices that are analysed with gyroscopic behavior tools, you conveniently try to finesse the issue. No, they aren't gyroscopes, but gyroscopic behavior, in the same sense that Kelley used the term, is applicable.
I'll even help you out by mentioning you would also find that the gysroscopic analysis of asymmetric turbine rotors is supportive of your "centrifugal" engine analysis, even if they don't use that sometime ambiguous term. I'll give you another hint ---- the relevant gyroscopic forces analysis can even be applied to individual rotors in the system.
Erik_K
New
quote:Originally posted by bbftx
quote:Originally posted by mandrin
bbftx, interesting observations. Gyroscopes are indeed truly fascinating devices. So counter-intuitive in their behavior. Interesting though how much effort is put towards saving HK’s ideas.
I like to remind that gyroscope rotors by definition have to have a very high degree of symmetry otherwise very large forces will be generated and hence useless in gyroscopes.
To compare a golfswing starting from zero speed with lots of torque applied and existing for only a very restricted arc to a gyroscope is just too much. An elastic can be super stretched, but.......
Let’s just decide that we should compare apples with apples and hence the only appropriate way is to look at the issue by utilizing the faithful and obedient centrifugal force, explaining it all very clearly.
It is not a question of being open minded or not. It is a simply a matter of not starting to invent a science to suit me but rather have science objectively tell me what is out there.
mandrin,
I am not inventing new science. If you'd read my post carefully, you'd note that gyroscopic behavior is relevant to wind turbine START-UP (i.e. restricted to the first cycle, starting from zero velocity -- like a "restricted arc" golf swing). YOU can shut your eyes to RESPONSES to your childish challenges, but any scientifically honest person would examine the analogy a little more thoroughly before dismissing it out of hand.
You used the term "perfectly symmetric" to try to discount the metaphor of gyroscopic behavior of an asymmetric golf rotor system. When presented with asymmetric examples of real-world devices that are analysed with gyroscopic behavior tools, you conveniently try to finesse the issue. No, they aren't gyroscopes, but gyroscopic behavior, in the same sense that Kelley used the term, is applicable.
I'll even help you out by mentioning you would also find that the gysroscopic analysis of asymmetric turbine rotors is supportive of your "centrifugal" engine analysis, even if they don't use that sometime ambiguous term. I'll give you another hint ---- the relevant gyroscopic forces analysis can even be applied to individual rotors in the system.
bbftx,
Your posts are very lucid and interesting. It seems that you and I might be on the same page in that we feel that Homer's work isn't totally perfect, but doesn't need to be in order to help explain how the golf swing works to other people.
And therein lies what mandrin will never fully understand. He wants this method (or maybe all things-perhaps he visits 12-20 sites like this daily quizzing others on the exact nature of this theory or that) to be technically perfect; all analogies and theories must be expertly defined and thoroughly verified through experiment or rigorous mathematical treatments.
Any engineer or scientist will never, ever, just outright claim someone's definitions, solutions, or assumptions are totally wrong without fully considering the context and circumstances of the problem. Mandrin saw the word gyroscope, didn't like the way HK used it and immediately calls into question how Homer could use such a term since it doesn't line up with the Physics for Dummies book on his desk.
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