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Post by imperfectgolfer on Oct 1, 2019 10:26:20 GMT -5
DG, You wrote-: "To create that conical motion with a larger #3 angle MUST involve increased angular velocity (and clubhead speed). They are directly proportional according to the maths of a conical pendulum."
What are you actually claiming when you state that a larger accumulator #3 angle must involve increased clubhead speed? Are you claiming that if two golfers are at the P6 position with the same degree of clubhead lag and hand speed, that the golfer who has a larger accumulator #3 angle at impact (which means that the clubhead path was more conically pendular between P6 and P7) will have a higher clubhead speed at impact - compared to the golfer who has the smaller accumulator #3 angle at impact? If you actually believe that "fact" please provide an explanation to support that "fact". You wrote-: "You mentioned "The golf club is experiencing an outward/center-fleeing pull" which is usually called a 'Centrifugal Force' . That is not exactly correct , because 'Centrifugal Force' is not a real force." I can readily accept the fact that from a theoretical physics standpoint, that there is no such thing as a centrifugal force. However, from a practical perspective, I "feel" like I am experiencing a center-fleeing force exerted by the releasing club when I swing my left arm around my body between P6 and impact, and it is chiefly a direct result of the PA#2 release phenomenon. That center-fleeing force that I "feel" is not tangential to the hand arc path, but it is felt roughly perpendicular to the hand arc path. At impact, many people claim that there is an outward pull (center-fleeing pull) of ~ 100lbs being exerted on the left hand by the club. Are you claiming that this outward-pull force exerted by the club on the left hand does not exist at impact - simply because there is no such entity as a centrifugal force in theoretical physics? Jeff.
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Post by dubiousgolfer on Oct 1, 2019 12:26:42 GMT -5
Dr Mann "Are you claiming that if two golfers are at the P6 position with the same degree of clubhead lag and hand speed, that the golfer who has a larger accumulator #3 angle at impact (which means that the clubhead path was more conically pendular between P6 and P7) will have a higher clubhead speed at impact - compared to the golfer who has the smaller accumulator #3 angle at impact? If you actually believe that "fact" please provide an explanation to support that "fact". That's a good question and all I can refer you to is Walter Lewins 'You Tube' video at 2:03 -2:17 . He says "Omega (angular velocity) and theta (#3 angle) cannot be arbitrarily chosen, they are coupled to each other". He then shows the equations proving that coupling from 3:00 - 3:36 youtu.be/2pvP-lWHMiQ"That center-fleeing force that I "feel" is not tangential to the hand arc path, but it is felt roughly perpendicular to the hand arc path. At impact, many people claim that there is an outward pull (center-fleeing pull) of ~ 100lbs being exerted on the left hand by the club. Are you claiming that this outward-pull force exerted by the club on the left hand does not exist at impact - simply because there is no such entity as a centrifugal force in theoretical physics" That pull force that you feel being exerted by the club on your hand is the 'inertia' of the club as you pull it around in a circle. It's a reaction pull force on your hand due to your hand pulling on the club. But I must admit that for golf instruction purposes it can be useful as Tutelman states below: www.tutelman.com/golf/design/swingwt1.php#phonyForce------------------------------- While we're questioning centrifugal force in the model... This page has drawn considerable criticism on the basis that centrifugal force is phony. True, some centrifugal forces are fictitious, but not all. The centrifugal force in this analysis is an example of the fictitious force, so the criticism is at least partly true. So why do I use it? Just because it is fictitious does not mean it gives wrong answers. There are plenty of fictitious constructs in physics, that we use because they behave analytically as if they were real, and centrifugal force is one of them. From a tutorial point of view, it is much easier for the non-physicist, non-engineer reader to understand. Here is a good explanation of the more classical physics. Not many people -- actually not even a majority of physicists and engineers -- would be able to visualize how release works from the diagrams and equations in the reference. You have to be able to mentally step through the Digital Differential Analyzer and see what the output would be. So, if I were actually writing a program to analyze the swing, I'd use d'Alembert's principle from classical physics (as in the link above) and never use centrifugal force at all. (Not that CF would give a wrong answer if programmed correctly, but it's much harder to program right.) But I still maintain that it's easier for most people to understand using centrifugal force -- so that's the way I'm explaining things for this tutorial. DG
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Post by syllogist on Oct 2, 2019 7:43:36 GMT -5
Dr. Mann,
Regarding clubface closure:
I consider clubface closure as the clubface becoming more perpendicular to the target line as the clubhead travels along an arc while "fleeing outward." I recognize that there is some axial rotation of the shaft
To respond to your question as to why it is that the left forearm does not rotate during final release with a very strong left hand grip, my answer is that it does slightly but it is difficult to see. What is easy to see is the ulnar deviation since the hand is more "on top" of the grip. Allow me to continue:
Do you agree that, if you put yourself in the "Miller" final release position and, without hand travel and keep your wrist "flat," rotate your left hand to make the club perpendicular to the target line, your radius and ulna bones will rotate but your elbow may appear not to rotate? It seems to me that the left forearm and elbow rotate if the humerus bone rotates about its axis. If so, then it seems to me that when looking at photos of release, one should not reference the elbow as an indicator of rotation. This is why I reference hand motion and rotation that are experienced during release.
S
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Post by imperfectgolfer on Oct 2, 2019 9:08:59 GMT -5
Dr. Mann, Regarding clubface closure: I consider clubface closure as the clubface becoming more perpendicular to the target line as the clubhead travels along an arc while "fleeing outward." I recognize that there is some axial rotation of the shaft To respond to your question as to why it is that the left forearm does not rotate during final release with a very strong left hand grip, my answer is that it does slightly but it is difficult to see. What is easy to see is the ulnar deviation since the hand is more "on top" of the grip. Allow me to continue: Do you agree that, if you put yourself in the "Miller" final release position and, without hand travel and keep your wrist "flat," rotate your left hand to make the club perpendicular to the target line, your radius and ulna bones will rotate but your elbow may appear not to rotate? It seems to me that the left forearm and elbow rotate if the humerus bone rotates about its axis. If so, then it seems to me that when looking at photos of release, one should not reference the elbow as an indicator of rotation. This is why I reference hand motion and rotation that are experienced during release. S I think that it is much more accurate to reference the lower radius bone just above the left wrist crease (relative to the left antecubital fossa) to determine the degree of left forearm rotation happening between P6 and impact - rather than the back of the left hand. It is obvious to me that there is very little external rotation of the left humerus happening between P6 and impact in most pro golfers.
You wrote-: "I consider clubface closure as the clubface becoming more perpendicular to the target line as the clubhead travels along an arc while "fleeing outward." I recognize that there is some axial rotation of the shaft."
You used the word "some" as if axial rotation is a minor part of the cause of clubface closure between P6 and impact. I personally believe that it is the major cause of clubface closure and it is entirely due to left forearm supination, and I believe that the clubhead "fleeing outward" does not cause any clubface closure in the absence of left forearm supination.
Have you ever read any of my "writing" on this topic?
Jeff.
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Post by imperfectgolfer on Oct 2, 2019 9:40:18 GMT -5
DG, It is worthless referring me to that Walter Lewin video, which is simply a mathematical presentation, which I cannot understand. If his mathematical calculations have any validity, then you should be able to present his "opinion" in simply prose language. I do not understand the mathematics underlying the D'Alembert principle, but I can understand how the concept explains the club-releasing phenomenon from a mental/intellectual perspective. I am waiting for Kevin Ryan, or Walter Lewin, or you, to explain in simple prose language how a greater degree of accumulator #3 angle during the later downswing can increase clubhead speed (independent of the speed of release of PA#2 in the plane of radial => ulnar deviation). Consider this comparison. Here are capture images of Jamie Sadlowski's late downswing. Let's presume that he has 80 degrees of clubhead lag at P6 and zero at impact (in the plane of radial => ulnar deviation), which means that there is 80 degrees of left wrist uncocking happening between P6 and impact.
Also, there is no conical pendular motion of his clubshaft happening between P6 and impact - as can be seen in the following DTL images.
Note that his hand arc path and clubshaft come straight down the TSP and that there is no clubshaft shallowing phenomenon. Note that his left arm is outstretched at impact with a very small accumulator #3 angle of <10 degrees - and that there is no conical pendular motion of the clubshaft happening between P6 and impact.
Don't you agree that his swing action is very conducive to a very rapid and efficient release of PA#2, which should maximise clubhead speed at impact? Now, consider Sergio Garcia's late downswing. Let's presume that SG has 80 degrees of clubhead lag at P6 in the plane of radial => ulnar deviation. However, at impact he still has 35 degrees of left wrist radial deviation remaining. That means that he only has 45 degrees of left wrist uncocking happening during his PA#2 release action (compared to 80 degrees for JS). Secondly, he has to rotate his left forearm a lot between P6 and impact in order to square the clubface, and this phenomenon is causally responsible for his clubshaft's conical pendular motion between P6 and impact. Do you not think that having an exaggerated conical pendular path will actually decrease the speed of release of PA#2 (rather than increase its speed of release) because the left forearm has to rotate while the club is releasing? You also wrote-: "That pull force that you feel being exerted by the club on your hand is the 'inertia' of the club as you pull it around in a circle. It's a reaction pull force on your hand due to your hand pulling on the club." I cannot really understand that point with respect to the P6.7 => P7 time period when the left hand is not pulling the club targetwards. To maintain a hub path constant during that time period, the centripetal pull must surely be equal to the outward pull of the released club and that outward pull is at right angles to the hand arc path, and not tangential to the hand arc path. Jeff.
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Post by dubiousgolfer on Oct 2, 2019 21:10:41 GMT -5
Dr Mann ""That pull force that you feel being exerted by the club on your hand is the 'inertia' of the club as you pull it around in a circle. It's a reaction pull force on your hand due to your hand pulling on the club." I should have explained my above sentence more definitively . When I meant 'pull it around in a circle' , its the pull force via the left arm (ie. increase in the arm tension) that creates a 'Moment of Force' across the COM of the club which causes it to rotate in a curvilinear path . Its not a pull of the left hand along its hub path. The red arrow represents the pull force (ie. increase in tension) via the lead arm which will create a 'Moment of Force' (ie. a torque force at a distance from the pivot point ) that will increase the angular velocity of the COM of the club (see black arrows). The above is actually described in maths by D'Alemberts principle and is responsible for 'Release' . It's the same physics used for 'Parametric acceleration' and also Sasho's 'Moment Arm'. The golfer would 'feel' an extra pull on their hands generally perpendicular to their hand path which will progressively increase as the club aligns up with the left arm. This is because the clubhead's speed and moment of inertia is also increasing so the golfer is having to pull more via the left arm to keep the club moving in a curved path into impact. The pull felt on the hands is the increased tension forces in the shaft which acts at both ends of the shaft , pulling on the hands at the grip end but also pulling on the COM of the club near the clubhead end. "Don't you agree that his swing action is very conducive to a very rapid and efficient release of PA#2, which should maximise clubhead speed at impact? "Yes, JS's swing is a perfect example for an efficient release of PA#2 without the need for PA#3. "Do you not think that having an exaggerated conical pendular path will actually decrease the speed of release of PA#2 (rather than increase its speed of release) because the left forearm has to rotate while the club is releasing? "This is a difficult question to answer. PA#2 is definitely 'short-circuited' early in SG's downswing but what about the initial speed of the clubhead just before release? Hasn't SG used a more 'downwards' motion over a longer distance and therefore had the opportunity to increase his clubhead speed (just before release) than say a golfer with less downward motion? Also, couldn't SG be using an active PA3# (via PP3#) torque with the paddling action of his right forearm to try and increase the angular velocity of the club? In which case that 'Ryke' angle and conical motion could be muscularly contrived rather than using the physics of the Ryke effect. We still don't know whether there is a feasible biomechanical action that will evoke the Ryke effect as per Kevin Ryan's software models. Until he publishes his findings , the Ryke effect just remains a possible physics phenomenon that may or may not be utilised in the golf swing. DG PS. Looking at that Walter Lewin video , the angular velocity is 'constant' (ie. tangential speed is constant) for that conical pendulum (angle 'theta') . But that doesn't happen in golfers swing if they have a specific Ryke angle from P6.5- P7, because their clubhead speed is increasing. Therefore the Ryke effect is not converting the double-pendulum motion to a 'complete' conical pendulum action. The physics is probably a lot more complicated and beyond my current understanding (maybe there is some partial assistance in club squaring using the Ryke effect physics and also some active PA3# ).
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Post by imperfectgolfer on Oct 3, 2019 9:18:41 GMT -5
DG, You wrote-: "Hasn't SG used a more 'downwards' motion over a longer distance and therefore had the opportunity to increase his clubhead speed (just before release) than say a golfer with less downward motion? Also, couldn't SG be using an active PA3# (via PP3#) torque with the paddling action of his right forearm to try and increase the angular velocity of the club? In which case that 'Ryke' angle and conical motion could be muscularly contrived rather than using the physics of the Ryke effect."
Here is a capture image of SG's hand arc path. I cannot see any evidence that his hand arc path has a much longer downward direction than most other pro golfers, but he does have a very "tight" turn in the P5.5 => P6 zone. Here is Cameron Champ's hand arc path.
However, SG does get his right elbow in front of his right hip area better than most pro golfers and he therefore has a later onset type of random PA#2 release pattern.
It is an interesting possibility that SG may be using an active right forearm paddlewheeling action to power his release of PA#3 and that may be needed to prevent a lot of left forearm supinatory motion (that happens in his late downswing) from slowing down his release of PA#2 because he has lot of over lap between the release of PA#2 and PA#3. Jeff.
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Post by dubiousgolfer on Oct 4, 2019 6:37:04 GMT -5
Even the maths does not make sense !!!
Correction: The maths makes sense but Kevin Ryans claims do not.
I looked at the Walter Lewin video and the formula he used for pure conical pendulum motion was: W*W = g/ {l*cos(theta)}.... equation1 W= Angular Velocity of the base circle, g= acceleration due to gravity, l = length of string (ie. clubshaft) , Theta = Ryke Angle
Tiger Woods clubhead velocity =129.2 mph = 57.8 m/s Length of his driver = 1.11 m gravity acceleration = 9.8 m/s/s Ryke Angle = 32 degrees Cosine(32) = 0.848
Plugging those values into the equation 1 we get W*W = 9.8/(1.11*0.848) = 9.8/0.94= 10.42
W*W= 10.42
W= 3.23
But V =RW (R is the radius of the circle at the base of the conical pendulum, W = Angular Velocity around circular base, V= linear velocity)
But R = l sin (32)
l = 1.11 Sin(32) = 0.53
Therefore R = 0.53 * 1.11 = 0.59
V= 0.59 X 3.23 = 1.9
V = 1.9 m/s
But Tiger Woods Clubhead velocity = 57.8 m/s !!!!!
Therefore , if I've got the maths correct , the Ryke effect does not convert a real golfers downswing to some pure conical pendulum action as I may have mistakenly thought Kevin Ryan implied. It might produce some effect on the component of speed in the late downswing from P6.5- P7 (superimposed on the original double pendulum action) but I don't even know whether it causes an increase/decrease or no impact at all.
I think I've convinced myself now that the Ryke effect might assist in club squaring but has a small impact on clubhead speed.
DG
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Post by syllogist on Oct 4, 2019 8:07:15 GMT -5
DG & Dr. Mann,
The more I think about Mr. Ryan's "physics discovery" ... Let's assume that we have a skilled golfer who gets to the position where his clubhead will start to flee outward. At that point, his left hand is in radial deviation. So, if one believes that the outward motion of the clubhead will begin to affect the golfer's hands, we would expect the left hand to undergo simultaneous rotation and ulnar deviation, thus having a "Ryke" angle during final release. Does it really matter within x degrees what the angle is between the left forearm and clubshaft at impact?
S
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Post by dubiousgolfer on Oct 4, 2019 9:27:41 GMT -5
DG & Dr. Mann, The more I think about Mr. Ryan's "physics discovery" ... Let's assume that we have a skilled golfer who gets to the position where his clubhead will start to flee outward. At that point, his left hand is in radial deviation. So, if one believes that the outward motion of the clubhead will begin to affect the golfer's hands, we would expect the left hand to undergo simultaneous rotation and ulnar deviation, thus having a "Ryke" angle during final release. Does it really matter within x degrees what the angle is between the left forearm and clubshaft at impact? S Hi S I would have thought the grip/setup might have an effect on degree of Ryke angle , or better control over the release of PA3 (to manage the rate of clubface closure per unit length of travel). If your lead hand grips the club 'neutrally' more in the fingers than palms won't that tend to increase the Ryke angle near impact ? DG
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Post by syllogist on Oct 4, 2019 10:50:08 GMT -5
Hi DG,
Very good question.
I think that:
#1 - grip along roots of fingers of left hand vs. #2 - grip from root of index finger to some point above root of pinkie finger
If the clubhead follows the same trajectory with both #1 and #2, then there would be more ulnar deviation by impact with #1. If not, then the trajectory of the clubhead would be different.
In either case, there would be likely be the same angle between the clubshaft and left forearm at the onset of final release.
S
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Post by dubiousgolfer on Oct 4, 2019 11:28:20 GMT -5
Interesting scenario.
Considering the 100N inertial force near impact exerted on the hands , I would have thought that golfers would have max ulnar deviation in a full driver swing. So if it was the same 'golfer/club/max ulnar deviation at impact/neutral grip' , that the golfer might have different setups (ie. Primary tilt/distance of arms from body) if their grip was in the fingers vs palms.
I could readily imagine they might also have different Ryke angles and probably different angles of attack.
DG
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Post by dubiousgolfer on Oct 4, 2019 17:52:21 GMT -5
I posted my maths on Kevin Ryan's you tube video and he either deleted it or someone else did !!!!
But he has responded to my previous comment 4 days ago and now stated the following:
"If I implied that the RYKE Effect increased CHS then that is incorrect. It is a mechanism that closes the clubface and adds very little to CHS. However I am now starting to understand sets of forces that can not only produce the closing of the clubface but also very significant increases in CHS. More of that later. I am still refining the process and understanding how and why these forces are generated. I am now convinced more than ever that I can achieve the 40 to 50 yard target. Kevin Ryan"
That comment above has actually annoyed me now because I have wasted many hours trying to check his claims.
I also don't even think it has much of a club squaring effect when the clubhead speed is moving so fast into P6.5.
I am now binning the RYKE effect.
DG
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Post by dubiousgolfer on Oct 5, 2019 5:52:49 GMT -5
More maths:
Tiger Woods Swing if Ryke effect evoked shows W= 3.23 radians/sec = 185 degrees/sec
If we assume Tiger Woods 1.1m length club had a Ryke effect at around P6.5 (45 degrees to vertical from a face one view) while pivoting around the lead wrist .
The distance the clubhead would have to traverse to impact (ie to clubshaft vertical) would be approx 0.86m
If the clubhead speed was 129 mph = 58 m/s , the time taken to move 0.86m at 58 m/s would be 0.015 secs approx.
If the Ryke affect was evoked, it would create an angular velocity in the horizontal base plane of that conical pendulum at a rate of 3.23 rads/sec = 185 degrees/sec ,
Therefore the number of degrees rotated in 0.015 secs = 185 x 0.015 = 2.8 degrees.
So , yes the Ryke effect does close the clubface by a very small amount from P6.5- P7
DG
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Post by utahgolfer on Oct 11, 2019 12:47:25 GMT -5
DG, thank you for posting the article on the incorrect use of the term, centrifugal force.
Could forum members clarify this article and state how our golf swing instruction should be corrected regarding this topic?
If CF is fictitious, then what is the correct way to explain it? Is the first step simply to call it centripetal force or CP?
On page 10, they have a drawing similar to the figure above and make the following statement, "swing the whole system in a plane around the upper lever's pivot, things happen as follows: to begin with the lower lever follows the swing of the upper lever and stays at a constant angle to it. Very soon, though, centrifugal force begins to throw the lower lever outwards, so that it begins to catch up with the upper lever."
How should this be stated to make it correct?
This has led many top teachers to develop the following INCORRECT theories: The Inside Moves the Outside; The big muscles of the leg, torso, and shoulders produce the power; Hip speed can produce shoulder speed, which can produce arm speed, which can produce clubhead speed; Both the direction and speed of the clubhead are controlled by your torso; The dog wags the tail;
How could each of these incorrect theories be said correctly?
Michael Hebron One example of using science incorrectly is in Michael Hebron's book, "See and Feel The Inside Move The Outside", on page 20, he states, "Centrifugal Force, or center force, is the principle of force or power that is directed or created from a central point. It is a developing force, moving from the center outward. Good shots in golf are a result of a sound swing that has centrifugal force." ALL PHYSICS BOOKS SHOW THIS TO BE INCORRECT
How could this teaching be stated correctly?
The INCORRECT beliefs in CENTRIFUGAL FORCE is a prime example of how you learn IN-SPITE-OF and NOT-BECAUSE-OF current teaching! If you really want to have great difficulty in learning the golf stroke, watch the golfing channel. All of their instructors teach scientifically incorrect principles.
How can golf instruction be improved based on having a correct understanding of CP?
Cheers, UG
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