Questions I have....
 

In 1-L-11 Homer states that clubhead force and motion is on plane at right angles to the longitudal Center of Gravity and varies with the Speed, Mass and Swing Radius.

I don't understand this sentence because im unsure what the longitudal center of gravity is.....

In 7-3 Homer says that the on plane Right Forearm shows the precise direction it and the clubshaft must take throughout the stroke.

now I know that per 1-L-5 The clubshaft lays full length on a flat tilted plane. So my question is when we turn our hand so that the palm is touching the plane won't the whole right wedge come off and the right forearm go below the inclined plane due to the impact fix degree of bend in the right wrist?

In 2-C-1 what does Homer mean when he says the angled clubshaft and the closing clubface are rotating around the same center?

Re: Questions I have....
 

I don't have my book with me to reference, but I think this might mean rotating the hosel. When I had a lesson with Ben two years ago, he stressed the sweetspot rotates around the hosel.

Re: Questions I have....
 

Longitudinal center of gravity as opposed to the transversional centre of gravity.

To find the Longitundinal centre of gravity, hang a string with a weight on the end from the grip. The string should hang vertically and go through the club's sweetspot.

To find the transversional center of gravity, just try to balance the length of the club on your index finger. Obvisouly, the fulcrum (your finger) should be nearer the clubhead because of its weight.

Re: Questions I have....
 

Problably just a typo, but the hosel rotates around the sweetspot.

:wink:

I think he had 'er the first time...

Sweetspot rotates around hosel.....anyone?

Nope the hosel rotates around the sweetspot.

Reason being is that the sweetspot is the center of the club portion that strikes the ball, not the hosel. Does that make sense? Now it does appear to the eye that when you rotate the club during the golf swing it might appear as the face is opening and closing around the hosel. But you are not directing the hosel you are directing the sweetspot. This the longitudal center of gravity line which you can see but exists and the forces applied to the club recogize it.

Wow I really don't understand how that works lol. :shock: :P

Mathew Quote:
"In 2-C-1 what does Homer mean when he says the angled clubshaft and the closing clubface are rotating around the same center?"

See 2-C-1 #3 - notice the impact condition of the leading edge and the shaft - they line up and also notice the point of separation condition - both the leading edge and the clubshaft line up i.e. point at the end of the grip or the same center of the circle of rotation.

Now, look at 2-C-2 #3- Vertical Hinging - notice how the leading edge at impact does not line up with the shaft but at separation it does. Angled Hinging produces a somewhat similar situation, and per 2-J-1 "Angled Hinging gives the Clubface a Slice producing uncentered motion", anotherwords the clubface motion has a different center than the clubshaft center, or put another way - the clubface motion is not centered to the same center as the clubshaft motion.

Of course, so does vertical hinging but since these are typically short shots where the Venturi effect has little opportunity to effect curvature of the ball flight- the uncentered slice charactistic is an irrelevant point in these situations.

Maybe others can add, correct or clarify further, that's about the best that I can do in regards to this question.

Substitute the word hosel with the word shaft.
We do not hit the ball with the shaft plane but with the sweet spot plane. The hosel then would move around the shaft or hosel.
If you place a thin rod on the sweet spot of the clubface and extend it to the grip- it forms a wedge shaped triangle. It is the rod that is on plane and if you make a golf stroke motion from the top through store position into impact- you will see that the hosel or shaft rotates around the thin rod- the sweet spot plane.

(PHEW!!!)

Nice post Mike. That "Slice producing uncentered motion" concept has been lurking in my Incubator for a long time now. I think I can finally remove it. :idea:

Here is another way to look at things, which should be read in conjunction with MikeO's well explained post.

Angled Hinging produces a clubface motion which goes from closed to open relative to the plane or clubhead line of flight (hence the slicing tendency), even though the clubface goes from open to closed relative to the target line.

One way to show this is if you take a club about two feet back using Angled Hinging (no roll feel), and then move your arms and club together as one unit to a horizontal plane (e.g. table) without disrupting any alignments, the clubface is closed.

Now take the club about two feet through the ball using Angled Hinging, and move your arms and club to the horizontal plane again without disrupting any alignments, the clubface is opened.

Note that the clubface closes at a slower rate compared with Horizontal Hinging. The center around which the clubface rotates around is different to that of the clubhead.

Slice Producing uncentered motion
 

Tongzilla,
It took me a second read as I needed to walk through your suggested procedure. But after initially being a little confused, I'd have to say, very nice follow-up post- I'm printing that one off for my archives! And I might add that Mr. Kelley was truly an amazing man to see all of this stuff!
Mike O.

"it"
 

You're correct. The problem you're having is with his writing style. Of course the forearm comes off plane in the backswing. Here are two possible corrections that I would use.

1) change "it" to "hands"
2) change "throughout the stroke" to "initially going back and then again immediately before and through impact".

Mathew- Your turn
 

Ok Mathew- three questions - three answers, how are we doing? Clarifications?

Exactly. It is not 'uncentered' is has a different center than Homer recognized.

Mike O - would you agree with the concept that the clubFACE center of rotation moves from left shoulder - horizontal, swing center - angled, right shoulder - verticle.

The clubHEAD center of motion remains the same for each

Sweetspot Around the Hosel or Vice Versa (Visually)
 

I vaguely remember this subject from about a year or so ago. Not sure if it was on the old THEGOLFINGMACHINE forum or Chuck's, or Brian's or here but...

If you hold the grip end of the club with your thumb and index finger and let the shaft hang down vertically, rotate/turn the club, the clubhead will initially appear to wobble around but you can see the clubshaft/hosel move around in a circle. I believe the center of that circle is the sweetspot.

PChandler

Ed,
1) Clubface motion has different center than clubhead - for angled / vertical hinging- AGREE
2) The Clubhead center is usually the left shoulder unless a right arm swing then the center would be the right elbow.
3) Regarding Clubhead center for horizontal hinging being the left shoulder
Clubhead center for angled hinging being the head or base of the neck, and clubhead center right shoulder for vertical hinging. I would say that Homer Kelley didn't see it that way, but you may see it or have a theory regarding that - but you'd have to clarify it.

Re: Mathew- Your turn
 

Unfortunately I am on my work nights and I will need to spend a little time with the thread, so will be busy over the next two days. But I promise to give this thread my full attention on Monday.... :)

No Center For Angled Hinging
 

Angled Hinging does not have a 'different' center for the clubface motion...It has no center.

Horizontal and Vertical Hinging are centered motions, with both Clubhead and Clubface revolving around the same Hinge Pin.

Re: No Center For Angled Hinging
 

Does "no center" for clubface motion for Angled Hinging imply that the center is constantly moving? If yes, from where to where?

centered?
 

Lynn,
You may be correct but since I can't see it, can you clarify what you're saying? In addition, per your post - assuming that the clubhead motion is constant- i.e geometry of the circle and on-plane, then we have two different clubface motions, both centered to the same clubhead motion. I'll need some help with your perspective.
Thanks,
Mike O.

PRESSURE POINTS
 

The pressure points in the hands ideally line up along the LONGITUDINAL CENTER OF GRAVITY line... along the handle of the club.

The Picture Worth One Thousand Words
 

To Tongzilla's question: Again, there is no center. Hence, it cannot move.

To Mike O's: This is one of the most difficult concepts in TGM. I could write paragraphs and still not have the message received. There must be an illustration...to communicate the words Homer gave me. I'll contact Mathew and interact with his creative skills. Stay tuned! :D

I'm looking forward to seeing your perspective. Mathew's work is always well done.

I supposed I can imagine that a 'perfect' angled hinge would have no center of clubFACE rotation, because it has no on plane rotation. The 'closing' is keeping a constant relationship to the other parts and is a 'relative' closing only (to the swing center/plane line).

By definition, any motion between pure horizontal and pure vertical is angled hinging. I believe that it is by far the most common hinge action. Even for those that think they are using one or the other.

Bagger

Yes, but the only case where there really would be 'no' center of clubFACE rotation in an angled hinge would be exactly at the mid point between horizontal, and verticle - the coin standing on edge.

The flatter the plane angle, the closer to horizontal hinge, the more upright, the closer to verticle hinge.

Hmmm....I wonder if that's really true.

According to Yoda, there is no center for Angled Hinging clubface motion -- end of story. Nothing about a midpoint Angled Hinge.

Interesting :roll:

We'll all have to wait for Yoda/Matthew's illustration for further clarification!

Still No Center For Angled Hinging
 

The essence of the situation is that with Horizontal Hinging, the Clubface is always only Closing as the Clubhead moves around its center. With Vertical Hinging, it is always only Laying Back. Hence, with Horizontal and Vertical Hinging, the two functions of the Club -- Head and Face -- can be synchronized around a single Center.

However, with Angled Hinging, the Clubface is simultaneously Closing and Laying Back. And the problem is that the Motion is not uniform. That is, there is no consistent relationship between the distance the clubhead moves forward and the degree the Clubface lays back (as it tries every split second to remain vertical to the Inclined Plane of Motion). Hence, the aggregate Motion has no center.

If all this is a bit much -- and it probably is -- just take what you can, throw the rest into your Incubator and come back later. Some things take time to 'see', and this is one of them. Homer Kelley came face-to-face with this illusive concept when he went looking for Angled Hinging's Center and couldn't find it. He ultimately solved the problem, but it took some doing. As he related to our January 1982 Masters Class:

"It has none. I had to build a model to find that out."

Different perspectives produce different concepts. I view the hinge action as being based on more of a universal joint/ball bearing type hinge.

Re: Questions I have....
 

The hosel rotates around the sweetspot, so does PP#3 do the rotating?

Spent the afternoon chipping, doing my chip, pitch, and punch drills through the set of clubs, ala Ben Doyle and felt a strong pp3 rotating the sweet spot. Succesfully I might add.