Ball being CompressedBall at Impact

 "Have Hhhhhhhhhhyy  Have you ever wondered what happened when clubface meet the ball? 
You will find the following information very interesting.
As Homer Kelley (author of The Golfing Machine) said;
"The Principle of Golf is the "Line of Compression". The  Mechanics of Golf is the production and manipulation of  the "Line of Compression" (LOC), The Secret of Golf is sustaining the "Line of Compression". 
The Principle of a plane is Drag and Lift. The Priniciple of a boat is Bouyancy and the Principle of Golf is the "Line of Compression".

Impact is the "Moment of Truth"


How long does the ball stay on the clubface?


When the clubface collides with the ball it's total contact time is approximately just under 1/2 Millisecond = 400 Microseconds = 0.0004 Seconds = 400/1,000,000 = 4/10.000 Second and the peak force applied to the ball can be as high as 4000 pounds.

1000 Mmilliseconds is equivalent to 1 (one) Second. This was very consistent with different clubs. This was measured with a camera that had 50,000 frames per second. 

Video - Ball on Clubface


Can the player do anything to the ball when the ball is on the clubface to influence how the ball takes off?


No. There is nothing the golfer can do at this point.


If two players make a golf swing with a 10 degree driver and both players are swinging the same at 100 mph and both have the same level strike, zero path, and both making a perfect impact but player # 2 is a much bigger and stronger person and weighing more than player #1 but both having the same impact alignments.

Can player #2 resist deceleration ,or in other words is there any way to make the hit heavier for player #2 if the clubhead was doing exactly the same thing to the ball as player #1?


No. During the impact once the clubhead has hit the ball nothing differently is going to happen.


If both players delivered the clubhead at the same spot at 100 mph, is there a difference if the club is Accelerating or Decelerating.


It could make a tiny difference.


If player #1 peaked at 108mph say 2 feet before the ball and coasted in at 100mph and player #2 at that same point was accelerating to 100mph and still that same 100mph for both is there going to be a difference and if so how many yards difference.


Just from the clubhead coasting through the ball it’s going to apply a force of about 1400lbs to the ball and that’s for a driver.

To accelerate a golf ball which weighs 1.62 ounces from Zero to 150 mph in Half a Millisecond it would require a force of about 1400lbs. 

A golfer during that part of the swing might be able to exert say about 20 lbs (100 Newtons of force). So 20lbs of force would be all that the golfer could manage compared to 1400lbs and a peak of thousands, is negligible.


When the clubface collides with the ball it's total contact time is approximately just under 1/2 Millisecond = 400 Microseconds =  0.0004 Seconds = 400/1,000,000 = 4/10.000 Second and the peak force applied to the ball can be as high as 4000 pounds. 

Conversion Millisecons to Microseconds to Seconds

 Microsecond means 1/1,000,000 or 1 divided by 1 million. So 1 microsecond is one millionth of a second. Another way to say the same thing is that 1 million microseconds make 1 second.

In the same way millisecond means 1/1,000 or 1 divided by 1 thousand. So 1 millisecond is one thousandth of a second. Another way is to say that 1 thousand milliseconds make 1 second.

Now 500 milliseconds will make 0.5 seconds. 4000 milliseconds is 4 seconds. In a similar way 500 microseconds is 0.5 milliseconds and 0.0005 seconds.

3000 microseconds is 3 milliseconds which is 0.003 seconds. 500,000 microseconds is 500 milliseconds which is 0.5 seconds. And so on.

400 microseconds is 0.4 milliseconds which is 0.0004 seconds. (Or another way 400 microseconds is 400/1,000,000 seconds = 4/10,000 seconds as you have. 


Is there any contribution then to the shaft of the club or are we dealing with a clubhead attached to a piece of string?


There are a couple of things that the shaft can do.

• The weight of the shaft at the very bottom contributes to the overall weight of the clubhead. Now that would be no more than six inches up from the bottom of the shaft and would contribute about 5 to 15 grams depending on the clubshaft to the overall head weight, so you have that in there.

• The shaft does a little bit to stabilize the gear effect. It is just the shaft being there and it doesn’t matter if the shaft is stiff, regular or ladies flex as the ball is on the clubface for such a short time.

There isn’t enough time for any vibration to come back and forth on the shaft. So there isn’t any contribution from the shaft flexing back and kicking during the impact as there just isn’t enough time.

The shafts natural frequency is just so much slower than it needs to be to be able to flex back and forth during impact.

• The shaft isn’t really doing anything.

• The clubshafts job is simply 99% of the time to deliver the head to the ball.

That 20lbs of extra force (as mentioned earlier) that the golfer might be able to exert on the ball during the impact interval is because the clubshaft is there to transmit that 20lbs and if the shaft wasn’t there then the golfer could transmit nothing.

The shaft will absorb through its own deflexion a part of that 20lbs so what the golfer actually delivers to the ball would be even less.

So the more flexible the shaft is, the more the shaft will absorb, so it is very negligible


How much closing of the clubface will occur when the driver contacts the ball and when the ball separates from the clubface in that less than one inch interval.


During that time not a huge amount. To give an idea of how fast this is all happening, the speed of the heel of the driver is about 10 mph slower than the toe of the driver, it is a huge difference.

If you made a practice swing without a ball in the way then over that distance the impact would occur the clubface would close about 1.5 degree but once a ball is in the way the clubhead will slow down so it may come down to about one degree. And that is if you are trying to do a Horizontal Hinging.

The following statement “The ball will leave the clubhead in the direction tho the face at separation”. This is not a correct statement.

If the clubhead is closing because it is travelling in a circular arc and If it is not just pushed with a piston straight at the ball, if it’s actually got some Angular Velocity when it meets the ball then the direction the ball will head initially is when the ball is at its most compressed point and not at separation.

At separation the clubhead has zero force on the ball. At first impact it has zero force on the ball. It is only where it is compressing the ball does it have a force.

If it meets the ball in an open position and closes directly square to the target at separation then all the forces in between will be in an open position. Then all the forces that are not in the direction of the target line will be to the right of the target line. For a right handed golfer.

In order to move the ball in the target direction, the clubface needs to open to square and then to close during the impact interval.

From maximum compression to final separation some of the forces have a component to the left of target to offset those forces which are to the right of the target.

So any statement that says that the ball heads of in the direction that the clubface is facing at separation is not right.

Now how much difference does that make is probably negligible because any golfer to know if he has the clubface square at impact, separation or somewhere in between is deluding himself to be able to have that extent of precision.  

The Elastic properties of the ball comes into play when the ball is compressed and then springs away from the Clubhead.

Friction torque also comes into play to set the ball spinning.


E-Wave Graphic Design & Website Development
X Close