Sweet Spot Plane

[mandrin]

– Homer in, 2-F. PLANE OF MOTION, defines a dynamic sweet spot plane separate from the shaft plane.

– Yoda to Martee: “Remember, Martee, don't confuse the Clubshaft's Impact Plane Line with the Sweetspot's Impact Plane Line. These are quite different!”

I got intrigued and had a closer look since I didn’t feel that a golfer is able feel the difference between these two planes.

As I analyzed Homer’s ideas I noticed that I disagree with the definition of his sweetspot plane. I agree that the orientation of his sweet spot plane is determined by the line of pull of centrifugal force. However the two anchor points he defines for this line of force are erroneous and hence the ensuing sweet spot plane plane.

The centrifugal force operates through the 2 deg of freedom ellipsoid lead arm wrist joint and the longitudinal center of gravity of the club. Homer however sees it operate through the lag pressure point and the sweet spot of the clubhead.

Since Homer uses a page on the subject and Yoda feels it is important, I thought it worthwhile to post my ideas so people can make up their own mind on the issue. If I am wrong than at least they have trough reflection obtained a better understanding of the issue.

 

[MizunoJoe]

In mandrin's world, the skilled player would shank every shot!

 

[Garth]

quote:Originally posted by mandrin

[brown]– The centrifugal force operates through the 2 deg of freedom ellipsoid lead arm wrist joint and the longitudinal center of gravity of the club. Homer however sees it operate through the lag pressure point and the sweet spot of the clubhead.

Thanks! my next swing thought! [8)]

 

[Martee]

This is one of my favorite research topics...

Based on Kelley's definitions of the Clubshaft Plane and Sweetspot Plane, I concluded and did several digrams to show that
a. The Sweetspot Plane is always flatter than the Clubshaft Plane

Note no one seems to agree with this or can see it.

b. The static measurement of determining the Sweetspot plane, as shown in your figure 1, does not indicate that it goes through the aft of the shaft at PP#3. (Your blue line in Fig 3 shows it does as so many like to define).

Now none of the above takes into account the dynamics, and assumes a standard position for the hands/wrists. Also the powering of the golf club will in fact add some other factors (pull vs push, thrust vs CF, etc.)

Taking into account the COG of the shaft, add the grip and the COG moves toward the top and then add the head and the COG moves toward the tip. (Static reference points).

Your accounting for the center of left wrist joint is questionable IMO as the force being applied/monitor are PP#1,2 and 3. A push by the right is applied PP#1 notwithstanding the level of the wrist. Same for the pull and if it is level or not.

I believe I have seen a picture of Homer demo CF using a club head (iron) and as piece of string. It essentially creates a stright line from the hand through the center of the clubhead (toe is a bit down).

I think your Mandrin's plane is a plane by you certainly would want to arrve at impact on that plane, unless you want to dig a lot dirt with the toe....

This concept is confusing IMO with how Kelley has defined it and applying his definitions, no one swings on the Sweetspot plane.

 

[Vaako]

This was in fact a cool post.


Vaako

 

[DOCW3]

quote:Originally posted by Martee

This is one of my favorite research topics...


no one swings on the Sweetspot plane.

Martee~

I have been working back from the Basic Motions (12-5) where I can feel the clubhead and lag pressure, and trying to understand the dowel drill. What I am presently working with is a yard stick placed above the right hand dowel from PP3 out to the sweet spot. The yard stick is the sweet spot plane and the dowel is the clubshaft. The dowel drill as I understand it, combines the right hand dowel into the sweet spot plane and the shaft plane. Where normally the shaft plane is inside the impact plane line, the dowell points at this line. At this time I can't forget about the shaft plane because it is included in the dowel. For now, I believe the answer is with the right forearm angle of approach and if there are differences in the two observations.

DRW

 

[mandrin]

quote:Originally posted by Martee

This is one of my favorite research topics...
....
....
This concept is confusing IMO with how Kelley has defined it and applying his definitions, no one swings on the Sweetspot plane.

Martee, when looked at in some detail the issues we are presently dealing with are not simple. The golf club is subject to three rotation centers. Not quite that easy.

However, I know from my math models that a golf club, once it acquires its higher velocity, at the bottom part of the swing, prior to and through impact, that the centrifugal force vector, for all practical purpose, operates through the distal hinge and through the mass centroid of the golfclub.

Once a high clubhead velocity is reached the centrifugal force becomes very dominant and any force applied by the trail/lead side can be ignored as to the effect it might have on the direction of the force vector operating through the wrist joint and passing through the center of mass of the club.

I am trying to put the whole issue of the ‘line of pull’, the ‘sweet spot plane’ and its relation to mass distribution, in graphical form to make the discussion and its implications accessible to the greatest number of people. However that will take a little time.

 

[Bono]

Mandrin...

I previously posted my number for you to call me for 2 days to discuss your knowledge - but to no avail (no call).

So...in this context, I will jump in the fray. I have reviewed your analysis (with open eyes - ), and can only conclude that - I have no clue.

But what I do know is this. The FEEL of the sweetspot plane is what Homer is referring to (and therefore - theoretically, one would continue on that plane)....

However. Since I am not a mathmatician nor a scientist...how would one feel the sweetspot plane through the lead arm wrist joint? Would you expect the pressure to be greater in the lead arm fingers?

BTW - Cell is still 302-299-9466.

Patrick

 

[MizunoJoe]

quote:Originally posted by mandrin

However, I know from my math models that a golf club, once it acquires its higher velocity, at the bottom part of the swing, prior to and through impact, that the centrifugal force vector, for all practical purpose, operates through the distal hinge and through the mass centroid of the golfclub.

Once a high clubhead velocity is reached the centrifugal force becomes very dominant and any force applied by the trail/lead side can be ignored as to the effect it might have on the direction of the force vector operating through the wrist joint and passing through the center of mass of the club.

I am trying to put the whole issue of the ‘line of pull’, the ‘sweet spot plane’ and its relation to mass distribution, in graphical form to make the discussion and its implications accessible to the greatest number of people. However that will take a little time.

mandrin - why don't you submit your ideas to the 'Science and Golf V: Proceedings of the World Scientific Congress of Golf'?

Here's a link for contact info - http://www.golfscience.org/

With proper scientific review, forum members, who read your posts will have confidence that you actually know what you're talking about! []

 

[Martee]

Several additional points..

CF can in fact be guided on to a path that it will operate from. So if the club is set on a particular path it will work from that point of reference.

Primary Lever (Left arm and club) with the left shoulder the center of the swing radius would create the feel center point that all would operate from in a swing.

Plane Boards seem to be an aid all agree on for the most part, yet that path (Inclined Plane) is the club shaft angle for the most part.

Most analysis of the golf swing will attempt to use lines to indicate on plane with the club shaft.

Homer's test for on plane, the shaft parallel to the plane line (some use the target line and and can be parallel lines depending upon set up or the sweetspot plane line with again can be the target line) or the end of the shaft closest to this line pointing at it, again revolves around the clubshaft orientation not the sweetspot orientation.

We can't see the line of pull, therefore we can't track it visually unless we get some aid(s).

One could make the arguement that from the left shoulder to this sweetspot is the line of pull.

Swingers and Hitters will have a different reference point as one is CF and the other thrust driven, the latter reduces the influence of CF to determine the orbit.

Just some random thoughts...

Key in all of this is that 'feel' and visual reality are not one of the same IMO. Something that has been missing.

 

[mandrin]

Martee, interesting thoughts.

Homer is also himself certainly adding to the confusion: In 2-F he states that,

“The full length of the Clubshaft remains unwaveringly on the face of this Inclined Plane - Waggle to Follow-through”.

He therefore clearly indicates that the club should be constrained to swing on the Shaft Plane. Yet a few lines further he introduces his Sweet Spot Plane.

Particularly for a driver there is drooping, a significant downward bending of the shaft during the swing, which significantly affects the sweet spot location and makes defining a shaft plane a dubious undertaken. Another reason to revisit Homer’s ideas on planes.

Martee, you should perhaps reconsider your idea that the line of pull is from the shoulder joint to the sweet spot. Actually the line of pull follows very closely the varying orientation of the shaft in space and does not have the lead shoulder as anchor point.

Your last line is the most important referring to feel vs real. Too many take there feelings and intuitions for hard reality and sometimes even science.

 

[mandrin]

quote:Originally posted by Bono

Mandrin...

So...in this context, I will jump in the fray. I have reviewed your analysis (with open eyes - ), and can only conclude that - I have no clue.

But what I do know is this. The FEEL of the sweetspot plane is what Homer is referring to (and therefore - theoretically, one would continue on that plane)....

However. Since I am not a mathmatician nor a scientist...how would one feel the sweetspot plane through the lead arm wrist joint? Would you expect the pressure to be greater in the lead arm fingers?

Bono, you looked at my post with open eyes and yet overlooked that I said that I don’t feel a golfer can sense objectively much difference between these various planes. []

I am having a closer look at Homer’s ideas since they are claimed to be the all encompassing universal golf method and therefore worthy of a careful reading. [8D]

A precision golf swing is an extraordinary exploit. I am much more modest than Homer. It is a fine feat of our neurons to do most of the job. Our contribution is only minor. [8)]

 

[mandrin]

quote:Originally posted by MizunoJoe

mandrin - why don't you submit your ideas to the 'Science and Golf V: Proceedings of the World Scientific Congress of Golf'?

Here's a link for contact info - http://www.golfscience.org/

With proper scientific review, forum members, who read your posts will have confidence that you actually know what you're talking about! []

MizunoJoe, would you be so kind to enumerate Homer’s scientific credentials.

 

[MizunoJoe]

quote:Originally posted by mandrin

MizunoJoe, would you be so kind to enumerate Homer’s scientific credentials.

Let's assume Homer, like you, has none. Why should I listen to you instead of Homer, who has published a book which gets praise from thousands of golfers world-wide, including tour players? [8)]

 

[Non-AuthorizedTGM]

WARNING:
Mathmeticians and Physicists often do not see eye to eye in the academic world....Should you expect this to be different here?...

The shaft only holds itself to the inclined plane when it rotates from its own plane to that of the sweetspot's plane during the backstroke for swinging..then it rotates from the sweetspot plane back to it's own for impact and the Hinge Interval..then again rotates from its own to that of the sweetspot for the finish swivel.....But the Sweetspot plane always holds itself to "tracing" the intended plane line!!!!

Now one thing I learned from my Ph D friends here at the University..You can argue theory until you're blue in the face..especially the "higher the degree" the more blinded by their own knowledge and use "psycho babble" to ward of intruders with their superior intellect..

However..."Golf Intellect" is measured Not by what you know..But What you can do... Many know a lot ...Few can do it themselves!!!!

I believe it's called the Alignment and Application of ......

Go apply the theory..only then does it become Principle....

"The NAT" without the G

 

[mandrin]

"The shaft only holds itself to the inclined plane when it rotates from its own plane to that of the sweetspot's plane during the backstroke for swinging..then it rotates from the sweetspot plane back to it's own for impact and the Hinge Interval..then again rotates from its own to that of the sweetspot for the finish swivel.....But the Sweetspot plane always holds itself to "tracing" the intended plane line!!!!"

NAT, above, crystal clear, and so simple and down-to-earth - I really love it. Any non-golfer reading this will instantaneously deeply regret not having taken up golf as it appears clearly from above to be a very fascinating sport. All those planes - inclined plane, own plane, sweet spot plane as well as hinge interval, finish swivel, plane line, tracing ...so much fun.

 

[Bono]

quote:Originally posted by mandrin

quote:Originally posted by Bono

Mandrin...

So...in this context, I will jump in the fray. I have reviewed your analysis (with open eyes - ), and can only conclude that - I have no clue.

But what I do know is this. The FEEL of the sweetspot plane is what Homer is referring to (and therefore - theoretically, one would continue on that plane)....

However. Since I am not a mathmatician nor a scientist...how would one feel the sweetspot plane through the lead arm wrist joint? Would you expect the pressure to be greater in the lead arm fingers?

Bono, you looked at my post with open eyes and yet overlooked that I said that I don’t feel a golfer can sense objectively much difference between these various planes. []
[8)]

I am not,in a position to dictate what a golfer - can or cannot sense...

Are you?

 

[mandrin]

"I am not in a position to dictate what a golfer - can or cannot sense..."

Bono, agreed, but you can tell me what you feel or sense and I am very interested to hear about your feelings and opinions re. the issue.

Why do you think Homer specifically mentions a sweetspot plane? Why do you think Yoda is convinced it to be very important.

You are an experienced TGMer, how do you go about knowing that you clubhead at over 110 miles/hour is moving on this sweet spot plane or not?

Why do you think does this sweetspot plane should go through the lag pressure point instead of the more obvious logical choice, the wrist joint?

How would you react if I conclusively show that Homer's plane is not correctly defined? Perhaps feel that feel and real are perhaps yet again not on the same wavelength?

Do you think Homer did write some form of scientific poetry re to sweetspots or does it have substance, meaning and value for to the serious golf student?

 

[MizunoJoe]

quote:Originally posted by mandrin

Why do you think does this sweetspot plane should go through the lag pressure point instead of the more obvious logical choice, the wrist joint?

The larger the #3 Accum angle, the less obvious that "logical" choice is. Your misconception might be explained by the fact that single-axis players zero out #3 at address.

 

[mandrin]

The larger the #3 Accum angle, the less obvious that "logical" choice is. Your misconception might be explained by the fact that single-axis players zero out #3 at address.

MizunoJoe, it would be very instructive if you slack a bit on reading Homer and start instead reading a bit up on real science, any normal textbook treating Dynamics will do. []

You basic error is to assume an equivalence between gravity force and centrifugal force. However that is not the case.

The gravity force vector field is uniform and existing independent of the motion of the golf club. This is not the case for the centrifugal force.

The centrifugal force is solely created by the motions of the golfer and club and hence dependent on the positions and motions in space, and the respective mass distributions.

However just hang on and I will in due time try to make this all clear. It takes however time to post responsible information on science related golf issues. [8)]