Golf physics..... interesting stuff

[G1BB0]

I found this site earlier and although the majority is way above my level mentally it is quite interesting

http://www.tutelman.com/golf/

I particularly liked the bit about accelerating through the ball.

http://www.tutelman.com/golf/swing/accelerateThru.php

anyway, enjoy

 

[Maninblack4612]

It's a brilliant website & has really helped my game. The proof he gives that any attempt to move the club head with the hands or arms slows reduces the swing speed is fascinating and putting it into practice has got me hitting the ball much better. Worth reading in detail.

 

[need_my_wedge]

Blimey mate, not sure what you spend your spare time googling....... That's some specialist golf porn ( hope I'm allowed to write that last word without getting in trouble?)

 

[G1BB0]

I am doing some drills with driver and was just googling impact stuff (sad I know) and found that, started reading and carried on, sad on a Saturday night I know lol.

 

[Crow]

Looks a really interesting site, I can see me spending a few hours reading through it, thanks for posting GIBBO.

 

[Foxholer]

If that doesn't satisfy you, try a book by another retired physicist Dr Ted Jorgenson is 'The Physics of Golf'.

Published when he was in his 90s, it introduced the concept of D-Plane. Interesting chap apparently - was responsible for measuring the size of the explosion at Los Alamos!

And guess what Dave Pelz was? At NASA.

It all comes down to physics in the end!

 

[G1BB0]

I was just reading a bit more of this, makes a lot of sense (obviously), maybe over technical for some but its nice to see that certain things I thought were important make negligible gains with regards distance etc.

bookmarked as I am deffo intrigued to read more, once a geek always a geek

 

[sev112]

It's a brilliant website & has really helped my game. The proof he gives that any attempt to move the club head with the hands or arms slows reduces the swing speed is fascinating and putting it into practice has got me hitting the ball much better. Worth reading in detail.

... Is only one theoretical presumption of how just one type of golf swing works.

This assumption that any hand action during a down swing causes a deceleration is a consequence of a false / over simplistic model of the forces and moments/torques on a golf club. It presumes that the connection between the hands and the grip can only transfer a force to the club through an assumption of a pinned joint between the two. In reality the connection is more fixed, and hence the hands can transfer a rotational torque to the grip which leads to a positive rotational acceleration to the shaft and the club head and hence in cased club head speed.

The simple presumption that many people propose suggests that any force applied to the grip forces the club to rotate backwards around its centre of gravity and therefore slows the club head down.

If you've ever seen a baton twirler, they do apply a rotational torque with their fingers which leads to faster rotation
Another parallel is drummers who apply rotational torques with their fingers to speed their drumsticks up.

 

[Foxholer]

There's also some good stuff in here (and some dross) http://people.stfx.ca/smackenz/publications.html

One or more of the studies does a 'more realistic' model than the Double Pendulum - by adding some torques generators in the areas Sev posted were missing/unrealistic.

 

[Maninblack4612]

The simple presumption that many people propose suggests that any force applied to the grip forces the club to rotate backwards around its centre of gravity and therefore slows the club head down.

I don't think this is the presumption at all. What the writer says is that, properly timed, the hands can add 0.7% to the speed of the club head but that it's almost impossible to time it this well & that a deceleration of the clubhead is more likely. I've seen time lapse photography elsewhere showing that, as the club head reaches the ball, the hands & arms, according to the law of conservation of angular momentum, are slowing down as the clubhead accelerates. It follows that any attempt to move hands & arms independently results in a slowing down of the club head. This has been my experience & knowing this he really helped my game.

There's a fascinating bit about how Trebuchets work on Tutelman's website. He explains how they hurl projectiles large distances in a way reminiscent of the golf swing and how there is no lateral force ,other than centrifugal force, applied to the sling, the equivalent of the golf shaft. In other words, club head speed is almost exclusively generated from the torso rotating the shoulders which, in turn, moves the arms, with the hands & club shaft acting as part of a double pendulum.

He also explains how people who think they generate power by whacking the ball with their hands (Ben Hogan included) don't. Endlessly fascinating, and I understand all this because I passed A level Physics 50 years ago!

 

[Maninblack4612]

There's also some good stuff in here (and some dross) http://people.stfx.ca/smackenz/publications.html

One or more of the studies does a 'more realistic' model than the Double Pendulum - by adding some torques generators in the areas Sev posted were missing/unrealistic.

Very interesting, not that I can understand much of it. However, one of the conclusions, how steep your plane is doesn't effect your ability to square the club face, is of great comfort now I've decided to ignore the people who have told me my swing is too flat for the last 55 years.

 

[Foxholer]

I don't think this is the presumption at all. What the writer says is that, properly timed, the hands can add 0.7% to the speed of the club head but that it's almost impossible to time it this well & that a deceleration of the clubhead is more likely. I've seen time lapse photography elsewhere showing that, as the club head reaches the ball, the hands & arms, according to the law of conservation of angular momentum, are slowing down as the clubhead accelerates. It follows that any attempt to move hands & arms independently results in a slowing down of the club head. This has been my experience & knowing this he really helped my game.

Joe Dante stresses COAM in his book 4 Magic Moves.

While COAM certainly contributes, Clubhead speed can be increased further by applying additional torque through muscle action. Check the papers on the Sacho MacKenzie site for the info - I think it's there.

 

[beggsy]

And I just hit the ball go find it hit it again never had a lesson and play off 8.4

 

[Maninblack4612]

And I just hit the ball go find it hit it again never had a lesson and play off 8.4

You, Bubba & Sam Snead, to name but three.

 

[Foxholer]

And I just hit the ball go find it hit it again never had a lesson and play off 8.4

Could have been 4.8 (or 14.8) if you'd had lessons.

 

[sev112]

I don't think this is the presumption at all. What the writer says is that, properly timed, the hands can add 0.7% to the speed of the club head but that it's almost impossible to time it this well & that a deceleration of the clubhead is more likely. I've seen time lapse photography elsewhere showing that, as the club head reaches the ball, the hands & arms, according to the law of conservation of angular momentum, are slowing down as the clubhead accelerates. It follows that any attempt to move hands & arms independently results in a slowing down of the club head. This has been my experience & knowing this he really helped my game.

There's a fascinating bit about how Trebuchets work on Tutelman's website. He explains how they hurl projectiles large distances in a way reminiscent of the golf swing and how there is no lateral force ,other than centrifugal force, applied to the sling, the equivalent of the golf shaft. In other words, club head speed is almost exclusively generated from the torso rotating the shoulders which, in turn, moves the arms, with the hands & club shaft acting as part of a double pendulum.

He also explains how people who think they generate power by whacking the ball with their hands (Ben Hogan included) don't. Endlessly fascinating, and I understand all this because I passed A level Physics 50 years ago!

I don't actually disagree with you, in that for most people, getting out of the way of the club doing its job would be a very good thing, in terms of distance and consistency. For most people, consciously trying to add some wrist torque is unlikely to get the timing right . But if one practises doing it , one can get the timing right.
Cricketers even manage delicate wrist torque when the ball is coming to them at 90 mph - it all comes from hours of practice

 

[Maninblack4612]

But if one practises doing it , one can get the timing right.

Mr Tutelman insists that, even if you do get the timing right, the maximum you can increase the clubhead speed is an insignificant 0.7% Unfortunately, this is based on physics I can't understand but is borne out by my own experience. For example, when in thick rough I used to try to give the ball an extra whack with the hands & was always disappointed with the result. What I now realise I was doing was dissipating the clubhead speed before I reached the ball.

Another example, I play with a fellow member who is 6' 3", weighs more than me and is 10 years younger, off a 3 handicap. In my view, he doesn't hit it anything like as far as he should, I can keep up with him at times. He can be seen to be really hitting very hard with the right hand and his predominant shot, almost amounting to a swing fault, is a big hook. The way I see it, the only thing his big right hand move does is to close the clubface, I don't think it adds to the speed at all. I'd love to get him to swing the way I think he should, but I don't think he'd take me seriously.

Personally, I'm hitting it as well as I ever have by feeling as if the upper body & shoulders are driving the arms, with the wrists firm but making no independent movement. Totally counter intuitive but, for me, very effective.

 

[Foxholer]

Personally, I'm hitting it as well as I ever have by feeling as if the upper body & shoulders are driving the arms, with the wrists firm but making no independent movement. Totally counter intuitive but, for me, very effective.

So just a sweep with no lag then? Or lag, but simply letting it release rather than adding 'snap' to it with some wrist torque?

There is definitely speed gains to be had from adding wrist torque, but how much is debatable. Given that I can get a decent speed on a non-turning 9-3 swing (so only wrist torque and gravity involved), I would think it's quite a bit more than 0.7%. Shoulder Torque is about twice as effective as Wrist torque though - because the effect is over about twice the distance - but every little helps!

 

[Maninblack4612]

So just a sweep with no lag then? Or lag, but simply letting it release rather than adding 'snap' to it with some wrist torque?

There is definitely speed gains to be had from adding wrist torque, but how much is debatable. Given that I can get a decent speed on a non-turning 9-3 swing (so only wrist torque and gravity involved), I would think it's quite a bit more than 0.7%. Shoulder Torque is about twice as effective as Wrist torque though - because the effect is over about twice the distance - but every little helps!

The way I feel it is that the lag is created & maintained by the hands being "left behind" as the shoulders lead the downswing, then release automatically with no conscious effort to "hit" the ball. It's a weird feeling but some of the shots it produces are ones I didn't think I was capable of.