A HELPING HAND

[golfbulldog]

Fascinating stuff

Thanks Mandrin

As you have stated - 3 Dimensional impact is important for sound as well as smash factor.

Maybe MARAD can take uoi the sonic signature gauntlet ? I have read a paper regarding sound of impact of a putter - published in a peer reviewed "somewhere else".

Surprised nobody tackled full swing.

Difficult to control for factors such as swing speed , degree of 3dimensionality of impact and centredness of impact on clubface... but by all accounts if you compress the ball it sounds different no matter what swing speed... there must be some way of recording this and comparing it with a flipped shot.

 

[Brian Manzella]

An old idea of mine...

Was to AMPLIFY the sound of impact as a "training" enhancement.

Through a "truck o'funk," so you could really hear the thwackp!

 

[Mike O]

3/4 of an each

SFTPS states in chapter 22 that "...the clubhead travels while in contact with the ball...more like three-quarters of an inch"

If the ball and clubhead travel 3/4 inch in contact together and the club is a 9 iron on descending path... the ball travels down into the ground...

maybe "trapped" is not good word but during impact interval ( 0.0005 seconds) the clubhead is touching the ball and the ball is touching planet earth - simultanously. Trapped / sandwiched ... whatever... does the earth exert a reactive force , through the realively solid ball , back against the clubhead?

GulfBulldog,
1) Chapter 22 - - 3/4 of an inch was with a driver 100 miles per hour- not sure the 9 iron is going to be moving 100 mph
2) The ball and clubhead don't travel 3/4 of an inch together- in a driver. 3/4 of inch is less than 1/2 the width of the ball- most of that distance is consumed by compressing/flattening the ball- the ball is not traveling anywhere during that time- relatively speaking.

 

[mandrin]

smart cookie

[size=-2]An old idea of mine... Was to AMPLIFY the sound of impact as a "training" enhancement.

Through a "truck o'funk," so you could really hear the thwackp![/size]

GMTA.

 

[Brian Manzella]

GulfBulldog,
1) Chapter 22 - - 3/4 of an inch was with a driver 100 miles per hour- not sure the 9 iron is going to be moving 100 mph
2) The ball and clubhead don't travel 3/4 of an inch together- in a driver. 3/4 of inch is less than 1/2 the width of the ball- most of that distance is consumed by compressing/flattening the ball- the ball is not traveling anywhere during that time- relatively speaking.

Mike O is VERY correct in this statement.

 

[matt]

GulfBulldog,
1) Chapter 22 - - 3/4 of an inch was with a driver 100 miles per hour- not sure the 9 iron is going to be moving 100 mph
2) The ball and clubhead don't travel 3/4 of an inch together- in a driver. 3/4 of inch is less than 1/2 the width of the ball- most of that distance is consumed by compressing/flattening the ball- the ball is not traveling anywhere during that time- relatively speaking.

Good points Mike...hadn't really thought of #2 that way before!

 

[golfbulldog]

agree

Good points Mike...hadn't really thought of #2 that way before!

yes, clears up that issue, thanks.

 

[rwh]

. . . 2) The ball and clubhead don't travel 3/4 of an inch together- in a driver. 3/4 of inch is less than 1/2 the width of the ball- most of that distance is consumed by compressing/flattening the ball- the ball is not traveling anywhere during that time- relatively speaking.

If the ball doesn't move, then how is it transormed from an object at rest to one that is travelling at the same speed as the clubhead immediately prior to separation?

 

[mandrin]

equivalent model

rwh,

To get an approximate idea of what happens, it is perhaps easier to visualize the ball replaced by a very simple equivalent model consisting of a spring and a mass.

The incoming clubhead compresses the spring and as this happens it transmits a rapidly increasing force, peaking 2000 to 3000 lbs, in only 0.0002 secs, to the mass.

Whilst the clubhead gives up part of its energy and rapidly slows down, the spring on the other hand stops being further compressed and rapidly starts to extend.

There comes a time when the relative speed between clubhead and mass changes from negative to positve at which time the mass/spring separates from the clubface.

Now back to a real golf ball.

Think of the ball as consisting of two parts. The part of the ball facing the clubhead acting as the spring and the other being the mass.

From the outside it may perhaps appear that the ball simply instantaneously goes along with the clubhead, whereas actually a very fierce and truly violent battle goes on between clubhead and ball with the ball getting violently deformed and only barely surviving the onslaught.

 

[rwh]

rwh,

To get an approximate idea of what happens, it is perhaps easier to visualize the ball replaced by a very simple equivalent model consisting of a spring and a mass.

The incoming clubhead compresses the spring and as this happens it transmits a rapidly increasing force, peaking 2000 to 3000 lbs, in only 0.0002 secs, to the mass.

Whilst the clubhead gives up part of its energy and rapidly slows down, the spring on the other hand stops being further compressed and rapidly starts to extend.

There comes a time when the relative speed between clubhead and mass changes from negative to positve at which time the mass/spring separates from the clubface.

Now back to a real golf ball.

Think of the ball as consisting of two parts. The part of the ball facing the clubhead acting as the spring and the other being the mass.

From the outside it may perhaps appear that the ball simply instantaneously goes along with the clubhead, whereas actually a very fierce and truly violent battle goes on between clubhead and ball with the ball getting violently deformed and only barely surviving the onslaught.

Very nice explanation. Thank you.

 

[jmessner]

GulfBulldog,
1) Chapter 22 - - 3/4 of an inch was with a driver 100 miles per hour- not sure the 9 iron is going to be moving 100 mph
2) The ball and clubhead don't travel 3/4 of an inch together- in a driver. 3/4 of inch is less than 1/2 the width of the ball- most of that distance is consumed by compressing/flattening the ball- the ball is not traveling anywhere during that time- relatively speaking.

I had a big discussion about the "trapping" issue on the Wishon forum some time ago. Keep in mind there is a shearing action, especially with the higher lofted clubs, that happens along with the compressive action. The ball actually slides up the face for a time before having enough compressive force to "stick" to the face. So it's not a given that the ball will be "pinched" with the ground and club. That said, there is still is an effect noticed by many golfers that a ball played off hardpan with a downward blow comes out with more spin than usual. I don't have confidence in any explanation for that, but Wishon has mentioned some preliminary data he has taken with a Trackman device (doppler radar based I think) that seems to confirm there is such an effect.

 

[LiftOff]

Mandrin

Great thread!

Very entertaining.

Tons of reads.

Lots of knowledge.

Stick around. Please.

Cliff

 

[mandrin]

LiftOff

Thanks,

A little appreciation goes a long way.

 

[Brian Manzella]

Here is my take.

I have sat on the sidelines on this one, but now seems like the right time to weigh in, so I will.

I have always believed in the "resist the collision" theory.

And, I am not totally giving up on it quite yet.

But...

Let's say Mandrin and others are correct. Lets say that the club-head acts as though it is disconnected to the shaft through the ball.

I can see it.

What we in "Classic TGM"-land feel when we really mash a 7-iron, may be just good contact with a "disconnected to the shaft" club-head—AND—the recovery of the "forward at impact flexed shaft" caused by the leading edge being slowed down by the divot.

Now, when I say "good contact," what I mean is everything that I have taught for 20+years, down-out-& forward contact with the sweet-spot.

To "prove" this to yourself, try to get that MASHED feeling with a high-teed 7-iron.

It isn't there.

Score one for the "disconnect" group.

More research is needed, but my always open mind is leaning toward Mandrin.

 

[mandrin]

Paradox

Brian,

Real is important and definitely has its place in golf but primarily as a supporting role.

What is required is an open mind and an appreciation that feel and real don’t always fit.

But also an appreciation of the paradox that feel is more important than real in golf.

 

[golfbulldog]

I had a big discussion about the "trapping" issue on the Wishon forum some time ago. Keep in mind there is a shearing action, especially with the higher lofted clubs, that happens along with the compressive action. The ball actually slides up the face for a time before having enough compressive force to "stick" to the face. So it's not a given that the ball will be "pinched" with the ground and club. That said, there is still is an effect noticed by many golfers that a ball played off hardpan with a downward blow comes out with more spin than usual. I don't have confidence in any explanation for that, but Wishon has mentioned some preliminary data he has taken with a Trackman device (doppler radar based I think) that seems to confirm there is such an effect.

Its amazing that there is no open access to this kind of data - impact is the core of golf swing , we have technology to measure and image better than ever ... yet we still debate what happens to the ball!

Open mind but an enquiring one...i will keep reading but would love to see some images and measurements to support these ideas.

Pragmatically doesn't make much difference - as Brian says the best impact is usually mashing a 3 dimensional impact. But it would be good to know what really goes on... ai suspect the club / ball manufacturers know but just don't want to tell us / eachother!

 

[jmessner]

Its amazing that there is no open access to this kind of data - impact is the core of golf swing , we have technology to measure and image better than ever ... yet we still debate what happens to the ball!

Open mind but an enquiring one...i will keep reading but would love to see some images and measurements to support these ideas.

Pragmatically doesn't make much difference - as Brian says the best impact is usually mashing a 3 dimensional impact. But it would be good to know what really goes on... ai suspect the club / ball manufacturers know but just don't want to tell us / eachother!

Yep, agreed. The premium ball manufacturers probably spend a fair amount on this kind of R&D and aren't in the habit of giving it away. There is some interesting stuff published by the World Scientific Congress of Golf, but some of the volumes are rather pricey and I haven't seen some of the latest work in this area.

 

[hcw]

Another take

I have sat on the sidelines on this one, but now seems like the right time to weigh in, so I will.

I have always believed in the "resist the collision" theory.

And, I am not totally giving up on it quite yet.

But...

Let's say Mandrin and others are correct. Lets say that the club-head acts as though it is disconnected to the shaft through the ball.

I can see it.....

More research is needed, but my always open mind is leaning toward Mandrin.

-The clubhead is not disconnected from the shaft and unless you literally let go of the club and throw it at the ball then the clubhead is never truly a disconnected body.
-When you swing the club, at some point the clubhead is accelerating.
-You can swing the club such that the clubhead is accelerating during the impact->separation interval.
-If you swing the club such that the clubhead is accelerating during the impact->separation interval, then you will be "resisting impact deceleration". (No, not by something you consciously/reactively do between impact and separation, just by the way you choose to swing the club.)

-hcw

PS- The whole conservation of momentum thing assumes the system is isolated, ie the affect of all external forces acting on the objects involved must be negligible. I don’t believe this holds if/when you can still be accelerating the clubhead.

 

[mandrin]

[size=-1]-The clubhead is not disconnected from the shaft and unless you literally let go of the club and throw it at the ball then the clubhead is never truly a disconnected body.
-When you swing the club, at some point the clubhead is accelerating.
-You can swing the club such that the clubhead is accelerating during the impact->separation interval.
-If you swing the club such that the clubhead is accelerating during the impact->separation interval, then you will be "resisting impact deceleration". (No, not by something you consciously/reactively do between impact and separation, just by the way you choose to swing the club.)

-hcw

PS- The whole conservation of momentum thing assumes the system is isolated, ie the affect of all external forces acting on the objects involved must be negligible. I don’t believe this holds if/when you can still be accelerating the clubhead.[/size]

hcw,

Your post is an excellent example why discussions often keep going on for ever on forums. Very reasonable and logic looking arguments and many will indeed agree, hence disuccions will carry on fueled by the various subjective feelings and opinions.

Yes, it is true that the clubhead is not disconnected from the shaft.

Yes, it is true that there can be resistance to impact deceleration.

Yes, it is true that the clubhead ball ensemble, during impact, doesn't constitute a closed system.

But, it is equally true that when you jump you move the earth.

The point above is clear, I hope. What is required is to objectively quantify your arguments and see of they still hold some water. If not they might remain interesting but don’t carry much weight any more.

One has to consider particularly the timescale involved in collisions, such as between clubhead and ball. Moreover, to compare the magnitude of the usually very large impulsive inertial forces inherent in collisions, with any possible applied external force.

This is exactly what I have done in a post quite some time ago. If you don’t agree with my arguments then you can put up your ideas but based on the reality of physics not on what you feel is going on. As in golf be wary of feel as it is often not in agreement with real.

 

[Brian Manzella]

All I can say is....

I test everything.

If I would have stuck with my 1994-96 pattern, I would have become a much better player. But—I am a teacher/researcher first. I test EVERYTHING.

I have been hitting balls for the past week and played one round of golf.

I have made the following adjustments:

I am using what I call the "mid-sole" wedge shot, almost exclusively. From teaching David Toms for a whole week the past four straight years, I have learned how he hits these shots. What a JOKE! It works so good it is like cheating.

Using this technique as a jumping board, and Mandin's idea of the DISCONNECTED clubhead, as well as doing what I figured out that 90% of the Tour does with the grip and clubface, I have changed my whole thought process.

Aimed Freewheeling clubhead, and a TOTALLY different loading/throw procedure.

All I can say is this:

I will post some video of my HARD TO BELIEVE ball-stiking in the next few days.



"Resistance to THOUGHT stops progress." —Bentley J. Doyle, PGA, G.S.E.D.