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Post by imperfectgolfer on Jul 9, 2012 20:22:42 GMT -5
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Post by imperfectgolfer on Jul 9, 2012 22:45:21 GMT -5
Consider Jeffy's irrational comment. See - jeffygolf.com/showthread.php?393-Is-anyone-in-golf-stupider-than-Michael-FinneyHe states that Federer was hitting a top-spin shot and that a top-spin shot must involve the ball being struck well below the center of the racquet face. What!!! When a good tennis player hits a top-spin shot, he still attempts to hit the ball in the center of the racquet face. However. the racquet face path is upwards - moving from "below-to-above" a horizontal plane through the immediate impact zone. There is zero evidence in that video that Federer's hand motion, and therefore racquet face path, is other than horizontal. That video simply shows an off-center racquet face strike. Top-spin is produced when the racquet face path is different to the racquet face orientation (which should face the target), and it does not imply an off-center strike. The same principle applies to a tennis player producing slice spin - the ball should be struck in the center of the racquet face (which should face the target), but the direction of the racquet face path should be from "above-to-below" relative to the target (the exact opposite scenario compared to top-spin). Jeff.
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Post by imperfectgolfer on Jul 10, 2012 16:33:07 GMT -5
BM made the following comment in that thread.
"Pure and Simple.
You CAN NOT make the face do ANYTHING during impact—even on purpose.
It is really a shame that folks waste time with this stuff.
Goofy. "
That's not the critical issue. I think that the important issue is whether having a stable left wrist through the immediate impact zone (between P6.9 -P7.2) decreases the amount of clubface rotation due to an off-center strike.
Jeff.
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Post by virtuoso on Jul 11, 2012 12:29:41 GMT -5
If, in the impact zone, your club has a dynamic pulling weight of about 100 lbs, wouldn't it be true to say the club is swinging your arms more than visa versa?
Is that an invalid assumption?
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Post by imperfectgolfer on Jul 11, 2012 15:26:09 GMT -5
I think that it is a totally invalid assumption to assume that the "club is swinging the arms" if the CF-loading weight at impact is 100lbs. I think that even an amateur golfer can easily handle a CF-loading weight of 100lbs if it only exists for a fraction of a second through the immediate impact zone. I am barely aware of the weight of the clubhead pulling outwards (in a CF-manner) when I am swinging the club between P6 and P8, and I easily manage to keep my hands moving along the "desired" hand arc path - in the presence of that CF-loading force. I have no difficulty swinging a standard length club with a clubhead of standard weight - and I never "feel" that the "club is swinging my arms".
I also don't believe that the dynamic CF-loading weight of 100lbs that is present when the clubhead moves through the immediate impact zone makes it more difficult to maintain a FLW/intact LAFW between P6.9 and P7.3.
Jeff.
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Post by virtuoso on Jul 11, 2012 15:44:40 GMT -5
Perhaps I should have said the club's inertia is swinging my arms at impact. Is that fair to say?
If I make a full swing with a club I can't stop at impact.
If I take a club and cut it off below the grip and try to simulate a full swing, I can almost stop dead at impact.
Assuming I can swing the grip a similar speed in both instances, how do I explain the difference if my arms are truely doing all the "swinging"?
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Post by imperfectgolfer on Jul 11, 2012 16:17:56 GMT -5
Virtuoso,
You wrote-: "Perhaps I should have said the club's inertia is swinging my arms at impact. Is that fair to say?"
If I understand your use of the term "inertia" then you are seemingly referring to the acquired momentum that the club has acquired by impact. However, that acquired momentum is directed mainly towards the target, and it is not a CF-loading force that is directed away from the center of the imaginary center of the clubhead arc circle. Under those circumstances, one has to keep the FLW moving actively targetwards to maintain an intact LAFW and prevent any flipping (clubhead bypassing the hands - which is more likely to occur in BM/MJ's "rotation-about-the-coupling point" release technique where he promotes right wrist straightening immediately after impact). If one actively leads with a FLW from P7 to P7.5+, then one can maintain an intact LAFW - even in the presence of clubhead inertia (club's acquired momentum) because they (FLW and club) are moving in the same general direction.
Jeff.
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Post by virtuoso on Jul 11, 2012 16:29:25 GMT -5
Let me ask you this: if we are talking about the clubhead, as it travels along the arc, if it becomes disconnected, it will fly off tangent to that arc.
If the clubhead stays connected and as such is forced to travel on the arc, then it is the clubhead's resistence to that constant "left turn" (acceleration) that is creating the dynamic pulling weight....or CF loading.
So aren't the clubhead's aquired momentum (inertia and it's resistance to any acceleration in direction or speed) and CF loading the same thing?
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Post by imperfectgolfer on Jul 11, 2012 16:42:46 GMT -5
Virtuoso,
You asked-: "So aren't the clubhead's aquired momentum (inertia and it's resistance to any acceleration in direction or speed) and CF loading the same thing?"
I don't think so.
Any CF-loading force is directed opposite to any CP-force present (which is directed radially towards the center of the clubhead arc circle). If the clubhead suddenly moves off at a tangent to the clubhead arc circle, then it is moving at 90 degrees to the direction of the radial force, and that is due to its acquired momentum. At low point, a tangent to the clubhead arc circle is directed towards the target.
Jeff.
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Post by virtuoso on Jul 12, 2012 11:12:46 GMT -5
See, to me, "CF loading" and the clubhead's inertia are the exact same thing.
I aint no scientist, but here is how I see it: in the impact zone, you not letting go of the club is CP, the clubhead has inertia that makes it want to go tangent or straight at every point on the circle and that is the "pull" you "feel" or CF.
Thus, CF and inertia are part and parcel of the same thing.
Am I smoking crack here?
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Post by imperfectgolfer on Jul 12, 2012 14:20:32 GMT -5
Virtuoso, I won't label you a crackhead, but I think that your understanding of clubhead inertia/CF-loading force is incorrect. They are not equivalent conceptually. The clubhead is tracking along the circumference of the clubhead arc between P6 and P7 due to its gained momentum and it is therefore tracking along the circumference of the arc at a certain finite speed (which optimally reaches a maximum speed at impact). That acquired momentum gives the clubhead its inertia in the sense that the clubhead would continue to travel at that gained speed at impact in the direction of the target (if the clubhead is square to the target at impact). What keeps the clubhead moving in a circular manner is the presence of a CP-force, and if that CP-force suddenly disappeared then the clubhead would no longer follow a circular path and it would travel in a straight line. The CP-force makes the clubhead arc path circular, but it is not the force that causes the clubhead to acquire a certain finite level of linear speed - as it travels along the circumference of the clubhead arc circle. Consider a car speeding around a circular racetrack. The engine supplies the power to make the car travel at a finite speed. If the driver turns the steering wheel so that the car continues to follow the circular path of the circular racetrack (and not leave the track in a CF-manner), then part of the engine's outputted energy is used for that purpose, but most of the engine's energy is directed at making the car travel as fast as possible along the path of the racetrack. The same analogy applies to a golf swing - the golfer powers the swing in order to create a certain finite amount of clubhead speed at impact, and he also wants the ball to be struck squarely by the clubhead so that the ball will be directed towards the target. While achieving his goal, he is also making the clubhead arc circular in shape and that means that he is also supplying a CP-force to keep the clubhead on the circular path of the clubhead arc, but that CP-force is not the force responsible for giving the clubhead its energy to move at maximum clubhead speed at impact. If all inputted CP-force was removed at impact - then the clubhead would move towards the target if the ball is at low point (nadir of the clubhead arc). It would not travel away from the center of the clubhead arc circle in a radial direction - which is what some people think of when talking about a CF-loading force that is radially-directed away from the center (and which is often conceived to be equal in power to the CP-force - but opposite in direction). Consider a hammer thrower preparing to sling his hammer-ball. He must be applying a CP-force while he spins in a circle keeping the hammer-ball a finite arm+chain's length away from his spinning torso. However, he spins as fast as possible in order to get the ball to gain its maximum linear speed as it travels along the circumference of its circular path - so that the hammer-ball can gain the acquired momentum to be thrown a long way when he lets go of the chain handle. That acquired momentum is directed at a tangent to the circumference of its circular path, and it is not directed radially away from the center of the circle (like a CF-loading force). The CF-loading force is only reflective of the magnitude of the CP-force that the hammer thrower is generating to keep the ball moving along a circular path (prior to release) - and it is not reflective of the hammer-ball's acquired momentum due to the speed of rotation of the hammer thrower's rotating torso. Jeff.
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Post by virtuoso on Jul 12, 2012 15:03:32 GMT -5
Gotcha, so having said all that, let me ask you this:
As I'm transferring kinetic energy to the clubhead through muscles, levers, the flail, etc, how close to impact can I get and still be transfering energy?
Is there some point before impact where I lose the ability to continue to add energy to the clubhead instantaneously......and further, to control clubhead orientation instantaneously?
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Post by nmgolfer on Jul 12, 2012 15:29:19 GMT -5
Virtuoso,
A Cp force can by definition NOT accelerate an object along the path. A cars engine does not need to work harder when it enters a turn. CF is the equal but opposite reaction to a CP (radial) force.
You can transfer energy to the club head all of the way to impact
nmg
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Post by imperfectgolfer on Jul 12, 2012 20:24:37 GMT -5
Virtuoso, You asked-: "As I'm transferring kinetic energy to the clubhead through muscles, levers, the flail, etc, how close to impact can I get and still be transfering energy?" There are two sources of energy needed - i) to move the clubhead along the clubhead arc path and ii) to resist any CF-loading force present. Consider a hammer-thrower again. The hammer thrower spins around the axis of his rotating torso in order to get the hammer-ball to increase its linear speed as it moves around the circumference of the hammer-ball path. When he reaches his maximum torso rotational speed, and therefore hammer-ball speed, he releases the handle and allows the hammer-ball to be thrown into space. Prior to release, he also has to work against the CF-loading force presented by the hammer-ball as it rotates around his body in a circular manner. That work represents a CP-force (normal force) and the magnitude of the work is dependent on the mass of the hammer-ball and its speed and the radius of the hammer-ball circle. The hammer thrower is leaning back and maintaining his spinal bend inclination constant while he rotates his torso, and that "leaning back" work-phenomenon (to resist the CF-loading force) occurs throughout the pre-release stage when his arms are fully extended (as in the photo). In a golf swing, a golfer also has to "lean back" to maintain his spinal bend inclination when the club releases - in order to produce the CP-force (normal force) needed to respond to the CF-loading force produced by the released club - so that the hand arc's circular path remains constant. Here is Miura's diagram showing that the magnitude of this CP-force (normal/radial force) increases during phase 3 of the downswing (between P6.3 and P7). The CP-force (normal force applied in a radial direction) is needed to respond to the CF-loading presented by the released clubhead. However, another force is needed to propel the clubhead along the circumference of the clubhead arc (at increasing speed) into impact. That force is supplied by the release of the power accumulators (PA#4 => PA#2 => PA#3 in a swinger and PA#1 => PA#2 => PA#3 in a hitter) and the power accumulators are only fully unloaded when both arms are straight (roughly at P7.3). I discussed these issues in great length in this review paper. perfectgolfswingreview.net/ManzellaRelease.htmIn BM's release model, he only talks about applying a normal force in phase 3 of the downswing (between ~P6.3 and P7) and he totally ignores the forces needed to increase clubhead speed along the circumference of the clubhead arc path. A golfer cannot only "pull upwards with all his might" (as recommended by BM) during phase 3 of the downswing - he also needs to continue to complete the release of his power accumulators in order to maximize clubhead speed by impact while simultaneously ensuring that i) he avoids flipping and ii) that the clubface orientation is square (zeroed-out) throughout its passage through the immediate impact zone (between P6.9 and P7.2).Jeff.
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Post by nmgolfer on Jul 12, 2012 22:46:05 GMT -5
Virtuoso
The CP/CF pair does not do any work.. ever. Work is defined as force times distance and force is real and positive but the distance term is zero. If you tie a rope to your car's bumper and lean into it but the car does not move... you have not done any work. There is tension in the rope but no work is done. High school physics
nmg
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