Acceleration of clubhead

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Ringer’s apparent trouble with the subject matter of acceleration in a golf swing inspired me to put some information together hoping that it will help people easier grasp this rather difficult subject of acceleration in curvilinear motion.
 
Excellent depiction! This also helps explain the shaft bending issue discussed in another thread. Early in the downswing the tangential dominates and the shaft bends away from the direction of travel, whereas near impact the normal dominates and (centrifugal:eek: force) acts throught the head CoG and bends the shaft forward.
 
I am trying to find out which part of TGM theory this issue is directed toward? Would it be most relevant to hitters, who push the club (axe handle) through impact? Or would it apply to understanding the power accumulators, such as # 3, so that one should not think that applying additional force at impact will matter? I know very little about the physics part, and I want to infer from this that we all should be swingers and focus on CF (or its equivalent if rightly described) and alignments.
 

Brian Manzella

Administrator
Great Question....

The reason that science is important to golfers has to do with knowing the TRUTH and trying to learn from it.

For instance, the "Heavy Hit."

It seems that science has said that it is a myth. My empirical evidence agrees. I adjusted my teaching, and the results have been very positive. My game is also much improved.

Acceleration is one of those term golfer teachers, announcers, and players throw around all the time. 99% of what they say about it is hogwash. I knew that in 1985, I almost never used the term. But, now thatnk to science—real science—I know why I was partially correct in my little Italian head, and why I wasn't. Teaching and Playing adjusted with positive results.

The advanced 3D systems thought me that there was no difference in speed with the flail working like a true flail or the club remaining up the left arm well past the ball. Where is that in any book?

There are many things like these three, and I hope for many more.

The Golfing Machine is a great work of a smart man, but this site does not exists to prove or disprove it. This site doesn't exist to explain it, or to bow to it. This site is about how to learn golf better, play better golf, teach golf better, and learn from the process while having some fun with it. It is a sounding board for someone who has plenty to say, but was HIDDEN—often on purpose—by the golf industry.

That would be me. ;)

What should you focus on in the swing?

If Hitting ideas help you, use 'em. My feeling is this:

I have my golfers set-up and grip the club in a way that will ENCOURAGE and ASSIST them in using the pattern I SUGGEST for them.

This pattern includes—stated to the student or not—a backswing hand and clubhead path, and plane shifts and lines, a certain motion of the pivot, and a desired and an attempted top of the backswing position (sometimes two different places).

The downswing includes hand and clubhead paths, axis tilt+rotation+location, an impact goal and location, and through the ball positioning of all the above, with and emphasis on the sweetspot and butt of the clubshaft location and rotation. At all times HAND CONDITIONS are stressed. Obviously there are many more "components" and "sub-components" to deal with, and they are when needed.

Hitting vs. Swinging?

Golfers need to use EVERYTHING that won't mess up the alignments to SNAP THAT CHAIN and hit that ball.

Certain shots work better with just a certain few.
 
Ringer’s apparent trouble with the subject matter of acceleration in a golf swing inspired me to put some information together hoping that it will help people easier grasp this rather difficult subject of acceleration in curvilinear motion.

Mandrin,
You can tell me the effect of a bending left elbow? In other words a second hinge in addition to the wrist cock.
Thanks
 
Mandrin,
Your model is configured for a steady straightening of the flail into impact.
What happens when you attempt to straighten the wrist cock early in the down swing?
In other words from the top throw the clubhead away from the target.
 
Mandrin,
You can tell me the effect of a bending left elbow? In other words a second hinge in addition to the wrist cock.
Thanks
mb6606,

I like to remind that this thread is about acceleration of the clubhead. ;)

The bending elbow is simply modeled by using three segments. On paper it allows more clubhead speed for the same effort. Timing becomes more difficult. Harry Vardon figures as a typical ‘3-segment’ golfer.
 

nmgolfer

New member
Now we're getting somewhere...

As noted by mandrin in an earlier thread, velocity and acceleration are vector quantities... they have both magnitude AND direction. By definition, Centrifugal is the (center fleeing) reaction to Centripetal (see wikipedia for the only two valid definitions of centrifugal) and it is (always) perpendicular to path. Centrifugal and centripetal share a common line of action and by the principle of transmissibility are an equal but opposites pair (action/reaction). Therefor they/it cannot cause a torque. Only figure 4 in Mandrin's nice write-up depicts a centripetal acceleration of the club head and notice this... it, as depicted, acts to retard the release of the club about the golfers wrists not cause it to happen! The tangential component of the acceleration (times the mass of the clubhead which equals a force) is in the simplified model shown, the force which causes the clubhead to release. It is NOT a "centrifugal force". Ringer was right this time.

Disregarding for a moment the small contribution due to gravity, the ONLY force acting on the club are those which the golfer imparts at the grip (both hitter and swinger efforts). There is no need to resort to mystical non-Newtonian and or imaginary "centrifugal torques" to fully describe what happens in a golfswing. The resulting motion of club is fully described by Mr. Newton's equations of motion F=MA and M=I*Alpha. One should keep in mind however that what Mandrin has showin us is not reality based.

That path of real golfer's hands does not trace out a circle; a constant torque is not applied at the hub of the pendulum; the motion of the club is anything but planar; real golfers do both linear and angular (torque at the wrists) work on the grip.... and the list goes on.

Thanks mandrin
 

Brian Manzella

Administrator
Good post nm...

When I was at the last TGM Summit, Dr. Zick provided a much more complete model that he used to show the proper time to ADD RIGHT ARM.

Mandrin surely is not dead on every time, but knows his stuff very well.

The model is always the problem, and no model really represents the actual swing of the golfer.

In the real world of teaching golf, which I reside in, I have NO PROBLEM "creating" long hitters.

I have no idea what kind of force is being created, but I know how to teach people to create it.

;)
 
Mandrin,
Your model is configured for a steady straightening of the flail into impact.
What happens when you attempt to straighten the wrist cock early in the down swing?
In other words from the top throw the clubhead away from the target.
mb6606,

The model is not really ‘configured’ to purposely do anything specifically. It is set up and physics takes over.

If you add positive wrist torque from the start it ‘unfolds’ the swing prematurely and it slows down and moreover it is quite detrimental for obtaining proper clubhead impact alignment conditions.

A positive wrist torque applied just prior to impact can augment clubhead speed somewhat. Most golf instructors likely will advice passive wrists or perhaps a bit of retaining torque early on in the downswing.
 
mb6606,

The model is not really ‘configured’ to purposely do anything specifically. It is set up and physics takes over.

If you add positive wrist torque from the start it ‘unfolds’ the swing prematurely and it slows down and moreover it is quite detrimental for obtaining proper clubhead impact alignment conditions.

A positive wrist torque applied just prior to impact can augment clubhead speed somewhat. Most golf instructors likely will advice passive wrists or perhaps a bit of retaining torque early on in the downswing.

I am trying to relate this to an actual golf swing. Should the wrist hinge be as loose as possible? Maybe Brian can answer.
 
mb6606,

I like to remind that this thread is about acceleration of the clubhead. ;)

The bending elbow is simply modeled by using three segments. On paper it allows more clubhead speed for the same effort. Timing becomes more difficult. Harry Vardon figures as a typical ‘3-segment’ golfer.

That is exactly what I am looking for - more clubhead speed.
 
mb6606,

If you add positive wrist torque from the start it ‘unfolds’ the swing prematurely and it slows down and moreover it is quite detrimental for obtaining proper clubhead impact alignment conditions.


Does your model describe the Pingman?
How would you increase the pingman's clubhead speed?
 

Bronco Billy

New member
Now we're getting somewhere...

As noted by mandrin in an earlier thread, velocity and acceleration are vector quantities... they have both magnitude AND direction. By definition, Centrifugal is the (center fleeing) reaction to Centripetal (see wikipedia for the only two valid definitions of centrifugal) and it is (always) perpendicular to path. Centrifugal and centripetal share a common line of action and by the principle of transmissibility are an equal but opposites pair (action/reaction). Therefor they/it cannot cause a torque. Only figure 4 in Mandrin's nice write-up depicts a centripetal acceleration of the club head and notice this... it, as depicted, acts to retard the release of the club about the golfers wrists not cause it to happen! The tangential component of the acceleration (times the mass of the clubhead which equals a force) is in the simplified model shown, the force which causes the clubhead to release. It is NOT a "centrifugal force". Ringer was right this time.

Disregarding for a moment the small contribution due to gravity, the ONLY force acting on the club are those which the golfer imparts at the grip (both hitter and swinger efforts). There is no need to resort to mystical non-Newtonian and or imaginary "centrifugal torques" to fully describe what happens in a golfswing. The resulting motion of club is fully described by Mr. Newton's equations of motion F=MA and M=I*Alpha. One should keep in mind however that what Mandrin has showin us is not reality based.

That path of real golfer's hands does not trace out a circle; a constant torque is not applied at the hub of the pendulum; the motion of the club is anything but planar; real golfers do both linear and angular (torque at the wrists) work on the grip.... and the list goes on.

Thanks mandrin

Hi nm

How the Hell are You :D ..... If What You Say is True Why does it Take One Full Quadrant for the Release to Start to Occur?

Cheers
 
Now we're getting somewhere...

As noted by mandrin in an earlier thread, velocity and acceleration are vector quantities... they have both magnitude AND direction. By definition, Centrifugal is the (center fleeing) reaction to Centripetal (see wikipedia for the only two valid definitions of centrifugal) and it is (always) perpendicular to path. Centrifugal and centripetal share a common line of action and by the principle of transmissibility are an equal but opposites pair (action/reaction). Therefor they/it cannot cause a torque. Only figure 4 in Mandrin's nice write-up depicts a centripetal acceleration of the club head and notice this... it, as depicted, acts to retard the release of the club about the golfers wrists not cause it to happen! The tangential component of the acceleration (times the mass of the clubhead which equals a force) is in the simplified model shown, the force which causes the clubhead to release. It is NOT a "centrifugal force". Ringer was right this time.

Disregarding for a moment the small contribution due to gravity, the ONLY force acting on the club are those which the golfer imparts at the grip (both hitter and swinger efforts). There is no need to resort to mystical non-Newtonian and or imaginary "centrifugal torques" to fully describe what happens in a golfswing. The resulting motion of club is fully described by Mr. Newton's equations of motion F=MA and M=I*Alpha. One should keep in mind however that what Mandrin has showin us is not reality based.

That path of real golfer's hands does not trace out a circle; a constant torque is not applied at the hub of the pendulum; the motion of the club is anything but planar; real golfers do both linear and angular (torque at the wrists) work on the grip.... and the list goes on.

Thanks mandrin
nmgolfer,

Since you are firmly denying credence to my ideas I am obliged to expose the fallacy in your arguments.

You argue that:

“Centrifugal and centripetal share a common line of action and by the principle of transmissibility are an equal but opposites pair (action/reaction). Therefor they/it cannot cause a torque.”

Let’s analyze this statement more closely since it involves a very fundamental error made quite frequently, even by those with a background in engineering or science. Fig1 shows pictorially, with a simple arrangement, the argument employed by nmgolfer. On first look it appears that nmgolfer is correct, yet he is totally wrong. ;)

freebodydiagram_1.gif



Anyone with a basic knowledge of physics is aware of free-body diagrams. Free-body diagrams are diagrams used to show the relative magnitude and direction of all forces acting upon an object in a given situation.

Figs 2a and 2b show these free body diagrams for our situation. There is only one force acting on the point mass M and there is only one real centrifugal inertial force acting on the ‘crooked’ segment. Gravity is ignored.

freebodydiagram_2.gif



In Fig3a shows the decomposition of the centrifugal force and Fig3b shows the resultant centrifugal toque acting on the ‘crooked’ segment. People will likely recognize the cog of the clubhead in our simple setup.

Hence, in conclusion, I have shown very clearly nmgolfer’s argument to be false and moreover I explained clearly the reality of the existence of a true centrifugal torque operating in a golf swing.

There is nothing fictitious about my arguments as used. There is no invoking of some mystical non-Newtonian and or imaginary “centrifugal torque as nmgolfer's claims I do. On the contrary I simply used common high school physics. :p

The other arguments in your post are equally basicaly wrong. Just hang on, you won’t miss anything waiting. When finding some time I will come back to your post and decorticate it with delight to show the errors made.

Nice Try But No Cigar. :D
 
Mandrin's model reminds me of the model used in Theodore Jorgensen's "The Physics of Golf". Jorgensen was pretty successful in getting the model to match the dynamics of a pro's swing, so I think the simplifications used don't inhibit its usefulness.

In any case, NM, I think the centrifugal force does indeed drive the release and you were using the centripetal vector whereas it's the opposite centrifugal vector that is acting on the shaft. Here's another article that I've seen in the past that describes this behavior (he references Jorgensen)

http://www.tutelman.com/golf/design/swing1.php?ref=
 
So many smart people on this site, anyone want to play a few holes for some ca$h? ;) You all are intimidating me :) lol
Jim,

You definitely should not be intimidated. Don’t get impressed.

Many (pseudo) 'scientists' don’t understand half of what they advance.

There is often plenty of action producing noise with empty drums. :D
 

Jim Kobylinski

Super Moderator
Jim,

You definitely should not be intimidated. Don’t get impressed.

Many (pseudo) 'scientists' don’t understand half of what they advance.

There is often plenty of action producing noise with empty drums. :D

Some would say that same thing with golf instructors too ;).
 
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