Acceleration of clubhead

[mandrin]

Hi There

Very Impressive Post as is the One about the Torques on the Shafts.... You certainly Demonstrated to Me in This Case F2 is a Real Force.... It Seems Like the Fire Has Gone Out of the Theoretical Posts.... How Unfortunate.... It Seems the Ones who have the Most to Gain from this Information are the One Who Get the Most Pissed Off.... They Do Not Realize that the Banter between the Giants(You and nm) is Part of the Process..... The Intruders Have and Probably Forever Will Retard Progress......

Cheers

Bronco Bil,

You are right on the money with your post. Some just gobble anything gathered up form anywhere without any critical thought. If it is stated aggressively enough on a web site it has to be the truth and accepted as such.

The root of it all is that scientists have always put the emphasis on a few real forces such as for example spring forces. Reaction forces, inertial forces are barely treated as real forces. Moreover this continuous confusion when mixing properties re inertial and non-inertial frames of reference makes it even worse.

Yet, Jean le Rond d’Alembert's (1717-1783 ) ideas and concepts, reformulating Newton’s basic second law of motion, should have made, after all those years, a greater impact on the notion of inertial forces behaving like real forces.

 

[mandrin]

Way to fool everyone with diagrams mandrin. If it weren't for the fact that I know CENTRIPETAL force is what is stretching the band, well, I'd be as ignorant as everyone who agree's with you.

Ringer,

Since you are the one who knows would you be so kind to explain. You can use English, mathematics, diagrams, figures, whatever you can come up with to convince me.

I am looking forward to your well-construed and convincing rebuttal.

 

[Ringer]

The argument remains the same mandrin. I've probably repeated it a hundred times.

The object at the end of your "elastic band" is trying to go 90 degrees away from your axis point. It is not pulling 180 degrees. The resistance to allow that to happen (centripetal force) is causing the elastic band to extend.

Your "resulting" force is the one keeping the axis in it's fixed place. There is no OUTWARD resulting force. Only momentum trying to travel in a straight line 90 degrees from the radius but constantly having it's direction altered by the centripetal force.

 

[Biffer]

The argument remains the same mandrin. I've probably repeated it a hundred times.

The object at the end of your "elastic band" is trying to go 90 degrees away from your axis point. It is not pulling 180 degrees. The resistance to allow that to happen (centripetal force) is causing the elastic band to extend.

Your "resulting" force is the one keeping the axis in it's fixed place. There is no OUTWARD resulting force. Only momentum trying to travel in a straight line 90 degrees from the radius but constantly having it's direction altered by the centripetal force.

Ringer,

Good discussion. Your persistence is admirable. It's obvious that mandrin is enjoying the test, so hang in there, because the rest of us are probably learning too.

Assuming that your above statements are correct, why is it that, when the arm is moving at a constant speed, the golf club moves from a 90 degree angle to straight in-line with the arm? What force causes the club to catch up to the in-line position?

 

[Ringer]

Ringer,

Good discussion. Your persistence is admirable. It's obvious that mandrin is enjoying the test, so hang in there, because the rest of us are probably learning too.

Assuming that your above statements are correct, why is it that, when the arm is moving at a constant speed, the golf club moves from a 90 degree angle to straight in-line with the arm? What force causes the club to catch up to the in-line position?

Imagine the left wrist is the axis point which the club is pivoting around. The right hand is on the club which is BELOW the axis point. So when the right arm extends, it is causing the club to swing around that axis point.

This makes it a function of the mechanics rather than a "force".

Also, don't forget that the forearms rotate relative to the ball which changes their relation to the plane. That change is another mechanical function which moves the club to the in-line condition.

If you take the club in just your left hand and turn your forearm so that it is holding the club horizontally in the air, this puts the clubhead "behind" the hands relative to the target. But rotate your left forearm, so that now you are holding the club vertically and you have created an "in line" condition where the hands and clubhead are even with each other. This isn't anything special that is a "force" of the swing, it's just the basics of your bodies relation to the plane line.

 

[Biffer]

[highlight]Imagine the left wrist is the axis point which the club is pivoting around. The right hand is on the club which is BELOW the axis point. So when the right arm extends, it is causing the club to swing around that axis point.[/highlight]

This makes it a function of the mechanics rather than a "force".

Also, don't forget that the forearms rotate relative to the ball which changes their relation to the plane. That change is another mechanical function which moves the club to the in-line condition.

If you take the club in just your left hand and turn your forearm so that it is holding the club horizontally in the air, this puts the clubhead "behind" the hands relative to the target. But rotate your left forearm, so that now you are holding the club vertically and you have created an "in line" condition where the hands and clubhead are even with each other. This isn't anything special that is a "force" of the swing, it's just the basics of your bodies relation to the plane line.

Yes, but when I swing the club with only the left arm, without the right hand
attached, the club still advances forward to the in-line position. Plus, I don't feel that the right arm straightening is pushing the club.

Sorry, but I don't understand your last paragraph. Could you please try to restate it for me? Thanks.

 

[mandrin]

The argument remains the same mandrin. I've probably repeated it a hundred times.

The object at the end of your "elastic band" is trying to go 90 degrees away from your axis point. It is not pulling 180 degrees. The resistance to allow that to happen (centripetal force) is causing the elastic band to extend.

Your "resulting" force is the one keeping the axis in it's fixed place. There is no OUTWARD resulting force. Only momentum trying to travel in a straight line 90 degrees from the radius but constantly having it's direction altered by the centripetal force.

Ringer,

Your discourse is a rather romantic, sweetly homocentric and doesn’t make much sense. Try to keep it simple and adhering to common sense. If an elastic band elongates - right in front of you - there is only one simple self imposing conclusion any reasonable person will accept:

A FORCE IS ACTING ON THE ELASTIC BAND​

Why is it so difficult to accept this simple fact?

 

[Ringer]

Ringer,

Your discourse is a rather romantic, sweetly homocentric and doesn’t make much sense. Try to keep it simple and adhering to common sense. If an elastic band elongates - right in front of you - there is only one simple self imposing conclusion any reasonable person will accept:

A FORCE IS ACTING ON THE ELASTIC BAND​

Why is it so difficult to accept this simple fact?

And I see your blissful glossing over of my answer continues to happen. I told you what force is acting on the elastic band. Centripetal.

 

[Ringer]

Yes, but when I swing the club with only the left arm, without the right hand
attached, the club still advances forward to the in-line position. Plus, I don't feel that the right arm straightening is pushing the club.

Sorry, but I don't understand your last paragraph. Could you please try to restate it for me? Thanks.

You have the left thumb on the shaft which is applying pressure on the club below the fulcrum. It's much HARDER to apply force with because of it's proximity to the fulcrum, but is still where force is applied. Otherwise, what is stopping the club from hitting you in the right shoulder on the way forward?

As for right arm pushing the club, it's called Extensor Action...there's no denying its existence.

In my last paragraph I'm asking you to hold the club out in front of you so that it is horizontal to the ground. Clubhead out in front of your right shoulder, hand in front of your left shoulder.

Now, keeping your arm where it is, just rotate your forearm so that the club is now vertical. Did you "release" anything to bring the clubhead in line with your hands?

BTW, that's accumulator 3.

 

[Biffer]

You have the left thumb on the shaft which is applying pressure on the club below the fulcrum. It's much HARDER to apply force with because of it's proximity to the fulcrum, but is still where force is applied. Otherwise, what is stopping the club from hitting you in the right shoulder on the way forward?

As for right arm pushing the club, it's called Extensor Action...there's no denying its existence.

In my last paragraph I'm asking you to hold the club out in front of you so that it is horizontal to the ground. Clubhead out in front of your right shoulder, hand in front of your left shoulder.

Now, keeping your arm where it is, just rotate your forearm so that the club is now vertical. Did you "release" anything to bring the clubhead in line with your hands?

BTW, that's accumulator 3.

Sorry, Ringer, but I'm still not sure what you mean. When I rotate the club from horizontal to vertical the wrists are still hinged, no release. I still have a 90 degree angle between the shaft and forearm. You mentioned "clubhead in line with hands" but I'm talking about going from 90 degree angle to in-line with the forearm.

 

[Ringer]

Sorry, Ringer, but I'm still not sure what you mean. When I rotate the club from horizontal to vertical the wrists are still hinged, no release. I still have a 90 degree angle between the shaft and forearm. You mentioned "clubhead in line with hands" but I'm talking about going from 90 degree angle to in-line with the forearm.

All I'm illustrating is that the forearm rotation also brings the clubhead even with the hands. It's a PART of the release.

 

[Brian Manzella]

All I'm illustrating is that the forearm rotation also brings the clubhead even with the hands. It's a PART of the release.

Really?

 

[mandrin]

Ringer,

Good discussion. Your persistence is admirable. It's obvious that mandrin is enjoying the test, so hang in there, because the rest of us are probably learning too.

Assuming that your above statements are correct, why is it that, when the arm is moving at a constant speed, the golf club moves from a 90 degree angle to straight in-line with the arm? What force causes the club to catch up to the in-line position?

Biffer,

We have to be quite careful as this subject is full of subtle booby traps. When you consider a double pendulum configuration the situation is very much dependent on the state of the hinge. This double pendulum configuration should not be considerd a simple extension of a circling point mass.

If the hinge is ‘frozen’, a centrifugal torque is indeed being developed. However, as soon as the hinge is made ‘free’ there still remains this centrifugal force acting on all particles, still producing some centrifugal stiffening and the centrifugal bending of the shaft, but it is not contributing anymore to a release torque.

It is nm who made me change my mind specifically on the release action. Strangely enough I had this information for years right at my finger tips but just did not see it. I realize that likely questions will be asked but since I do this for pleasure and not due to any obligation one has to wait till I am ready to post more in detail about this subject.

But in the mean time I am sure that Ringer will fill the void and give appropriate explanations.

 

[mandrin]

And I see your blissful glossing over of my answer continues to happen. I told you what force is acting on the elastic band. Centripetal.

Ringer,

The centripetal force is acting towards the center. How can it stretch the elastic band which requires a force acting away from the center?

 

[Biffer]

Biffer,

We have to be quite careful as this subject is full of subtle booby traps. When you consider a double pendulum configuration the situation is very much dependent on the state of the hinge. This double pendulum configuration should not be considerd a simple extension of a circling point mass.

If the hinge is ‘frozen’, a centrifugal torque is indeed being developed. However, as soon as the hinge is made ‘free’ there still remains this centrifugal force acting on all particles, still producing some centrifugal stiffening and the centrifugal bending of the shaft, but it is not contributing anymore to a release torque.

It is nm who made me change my mind specifically on the release action. Strangely enough I had this information for years right at my finger tips but just did not see it. I realize that likely questions will be asked but since I do this for pleasure and not due to any obligation one has to wait till I am ready to post more in detail about this subject.

But in the mean time I am sure that Ringer will fill the void and give appropriate explanations.

Aha! Thanks for the clue mandrin. I think I now see what the heck is going on here, at least partly. How clever you are! Can't wait to see if I'm right.
Thanks much.

 

[jmessner]

All I'm illustrating is that the forearm rotation also brings the clubhead even with the hands. It's a PART of the release.

Ok, I'm hoping Brian's response to this was sarcastic because while I don't agree with Ringer's Physics, I'm starting to think the rolling is an important part of the release. If you think about it, the rolling has a bigger impact on clubhead speed with a larger wrist cock angle since the club will trace a larger arc when rotated. So a swing that exhibits a delayed wrist cock AND delayed forearm rotation has real potential for speed. Of course, I haven't done any math on this yet, so I could be all wet.

 

[mandrin]

Ok, I'm hoping Brian's response to this was sarcastic because while I don't agree with Ringer's Physics, I'm starting to think the rolling is an important part of the release. If you think about it, the rolling has a bigger impact on clubhead speed with a larger wrist cock angle since the club will trace a larger arc when rotated. So a swing that exhibits a delayed wrist cock AND delayed forearm rotation has real potential for speed. Of course, I haven't done any math on this yet, so I could be all wet.

jmessner,

I would like to suggest that you consider more closely cause and effect. What about golf robots? Some instructors teach golf with minimum roll of arms, how do they get still normal clubhead speeds if roll is such a dominant factor for producing clubhead speed?

 

[birdie_man]

I hear the humming of a large electric freezer...........

(mmmm popsicles)

 

[hcw]

Say What!?

...It is nm who made me change my mind specifically on the release action. Strangely enough I had this information for years right at my finger tips but just did not see it....

does this mean that everything the amazing mandrin tells us is NOT the truth, the whole truth, and nothing but the truth?...shocked, shocked i am!

 

[jmessner]

jmessner,

I would like to suggest that you consider more closely cause and effect. What about golf robots? Some instructors teach golf with minimum roll of arms, how do they get still normal clubhead speeds if roll is such a dominant factor for producing clubhead speed?

Well, I don't think I used the word dominant but I'm just vetting this theory. It' s a learning experience either way. Again, the premise here is achieving maximum clubhead speed which is what I gather many of the posters have been after with this thread.

Anyway, yes robots can achieve, I assume, normal swing speeds with no roll but to me that doesn't mean that humans are most effective that way.

Instructors that teach minimal role may be after more accuracy than distance, I don't know. If so, that's probably better for amateurs anyway. But, after looking at few long hitters swings this weekend (Bubba Watson, Tiger) they have a healthy roll of the wrists late in the swing.

It also could be that it's a better swing thought. I will admit that when I feel like I'm minimizing my forearm roll (at least on the backswing), I can achieve relatively high swing speeds so maybe it's a feel vs real thing also.

But, indeed, I may be missing the cause and effect link. Is the roll an effect vs a cause in your opinion?

Jay