Ball Flight Laws

[Damon Lucas]

Brian,

Could you post a modern set of ball flight laws, with some numbers to enhance our understanding of them?

Could you also describe the many factors affecting ball flight, with their relative importance emphasised?

Regards,

 

[Brian Manzella]

I have been working on one, but start with this...

The ball STARTS where the clubface is at separationa and curves AWAY from the path (plane line).

 

[Damon Lucas]

Brian,

As per our discussion, I copied this tally of reasons as to why the golf ball 'flies' the way it does!

It would be great if you could add to it, discuss potential omissions from the list, the importance of the various listed componants, and of course your opinions.


Is there any available research data?

The curvature of the ball is obviously a combination of a few more facors than just face and path....but for the average junkie..that's enough...what other factors might be involved....

1.) Ball Speed
2.) Launch Angle
3.) Vertical Spin Rate/Horizontal Spin Rate
4.) Drag
5.) Gravity
6.) Clubface Motion/Hinge Action
7.) Loft
8.) Lie/Plane Angle
9.) Moment of Inertia of the Head
10.) Torque
11.) Shaft Flex
12.) Overall Weight
13.) Bend Point
14.) Dimple Configuration
15.) Vertical, Horizontal, and Longitudinal Center of Gravity of the Clubhead...
16.) Angle/Arc of Approach
17.) Angle/Arc of Attack
18.) Ball location
This is probably just the tip of the iceberg....but at least it's a start......

 

[tongzilla]

Where did you grab that list from, Homerson?

 

[Damon Lucas]

The list is from Annikan Skywalker,who posted it on Lynn's forum. Brian added that point of contact on the clubface was also an influence.

I am interested in what Brian says is the relative importance of each factor(if any).

For me, it took getting used to that the ball started where the clubface pointed at separation! I still have had plenty of good ball striking rounds, but have always been mindful(fearful??) of the double cross, and no teacher had explained it. It's nice to know that it is simply physics and geometry!

Regards,

 

[tongzilla]

Brian or anyone else, how can you explain this.

I hit a 40 yard pitch shot the other day. The divot was pointing well left of target (about 10 degrees). And yet the ball went towards the flag with some hook spin (right to left) on it. The ball always leaves 90 deg to Clubface, so the Clubface must have been open relative to Clubhead path (assuming the divot shows Clubhead path). But wouldn't that impart slice spin (due to divergence between the face and path)?

Edit: no wind or any other weired stuff.
Edit again: I don't have an answer either by the way...

 

[Tom Bartlett]

quote:Originally posted by tongzilla

Brian or anyone else, how can you explain this.

I hit a 40 yard pitch shot the other day. The divot was pointing well left of target (about 10 degrees). And yet the ball went towards the flag with some hook spin (right to left) on it. The ball always leaves 90 deg to Clubface, so the Clubface must have been open relative to Clubhead path (assuming the divot shows Clubhead path). But wouldn't that impart slice spin (due to divergence between the face and path)?

Edit: no wind or any other weired stuff.
Edit again: I don't have an answer either by the way...

The ball doesn't ALWAYS leave the club face at 90 degrees. The more severe path the more influence it has on ball flight to club face.

Do your clubs fit you properly? In other words lie angle. I have seen this happen when the lie angle is incorrect it gives a "false" divot.

 

[tongzilla]

quote:Originally posted by Tom Bartlett


The ball doesn't ALWAYS leave the club face at 90 degrees. The more severe path the more influence it has on ball flight to club face.

This isn't in the book, but I also suspect the greater the compression, the more path influences ball flight.

quote:Originally posted by Tom Bartlett


Do your clubs fit you properly? In other words lie angle. I have seen this happen when the lie angle is incorrect it gives a "false" divot.

From the information given in my last post, can you tell whether the lie angle of my wedge is too upright or too shallow?

 

[shortgamer]

Wait, wait, wait I thought that the ball started on the swing path direction and then curved according to the face angle.Let me get this straight, if my clubface is pointed directly at the target at seperation but my swingpath is inside/out then the ball will start at the target and draw? If this is true and Brian says you need a slightly open face at seperation with a inside/out swingpath then wouldn't every shot be a push? Just trying to understand.....

 

[Tom Bartlett]

quote:Originally posted by shortgamer

Wait, wait, wait I thought that the ball started on the swing path direction and then curved according to the face angle.Let me get this straight, if my clubface is pointed directly at the target at seperation but my swingpath is inside/out then the ball will start at the target and draw? If this is true and Brian says you need a slightly open face at seperation with a inside/out swingpath then wouldn't every shot be a push? Just trying to understand.....

If you are trying to hit a draw</u>, let's say clubface open 2 degrees at separation and path 4 degrees inside out. Only time ball will go straight is if path and clubface match at separation.

 

[Tom Bartlett]

quote:Originally posted by tongzilla

From the information given in my last post, can you tell whether the lie angle of my wedge is too upright or too shallow?

Leo, I would guess too upright because of the info you gave me. Too upright clubs will make the divot longer on the left side of the divot giving the pull impression and you said you drew it, which would also be aided by clubs that are too upright.

 

[tongzilla]

quote:Originally posted by Tom Bartlett


Leo, I would guess too upright because of the info you gave me. Too upright clubs will make the divot longer on the left side of the divot giving the pull impression and you said you drew it, which would also be aided by clubs that are too upright.

Damn...you just got me more confused now! Actually, I remember Brian saying I needed to have my iron's lie angle more upright. I probably need to go to a clubfitter, since I hits these type of shots quite often, and I want to find out why 'cos it's really bothering me.

 

[hue]

Leo: I played a partial wedge shot the other day and the shot had a huge draw shape. The ball had a big lump of mud on one side. www.precisiongolf.co.uk the clubfitters I told you about have a huge 12 page article on them in this month's Golf International Magazine.

 

[MizunoJoe]

There are two sets of ball flight laws - one for balls compressed by an on plane clubhead in which rotation of the ball depends on deformation of the mass of the ball and another in which the spin is determined by friction - polishing the ball.

 

[shortgamer]

MJ, could you tell us more?

 

[RicoSuave]

angle of incidence = deflection

if you hit a ball in a shallow angle against a wall, it will never deflect perpendicular to the wall.

So it doesnt matter if the ball flies to the wal or the wall hits the ball. (except that the ball has already spin).
So IMO if you swap the wall with a clubface the ball wont leave the face perpendicular.
Perhaps Mandrin could give us dummies some hints.
tia Rico

 

[jmessner]

if you hit a ball in a shallow angle against a wall, it will never deflect perpendicular to the wall.

So it doesnt matter if the ball flies to the wal or the wall hits the ball. (except that the ball has already spin).
So IMO if you swap the wall with a clubface the ball wont leave the face perpendicular.
Perhaps Mandrin could give us dummies some hints.
tia Rico

It's all about frame of reference - if you view the clubhead as a stationary then the angle of incidence reaction you described above holds (ignoring friction). However, as viewed from a stationary observer you would have to add the clubhead velocity vector to the ball rebound vector. Net result is the ball leaves basically perpendicular to the face (again ignoring frictional forces). I hope that makes sense.

 

[RicoSuave]

It's all about frame of reference - if you view the clubhead as a stationary then the angle of incidence reaction you described above holds (ignoring friction). However, as viewed from a stationary observer you would have to add the clubhead velocity vector to the ball rebound vector. Net result is the ball leaves basically perpendicular to the face (again ignoring frictional forces). I hope that makes sense.

IMO the force vector of the club is always to the center of the ball.
So for the ball it doesnt matter where you are aiming at.
I just want to simplify the system and ask in which angle the ball is leaving the club.

In nature, when you hit a wall there is friction and compression between them, and you will never see the ball bouncing perpendicula to the wall back on to the fairway. (saves some strokes after a duck-hook ;-)

So as you can see in my graphic you can use the same system for ball and wall.
Hope you can correct or confirm my thoughts.
tia Rico

 

[hcw]

So as you can see in my graphic you can use the same system for ball and wall.
Hope you can correct or confirm my thoughts.
tia Rico

hmmm, i think maybe what you are missing is that the clubhead/face is moving between impact and separation and the wall isn't...

-hcw

 

[jmessner]

Missing clubhead speed and direction

Try this:



This assumes a perfectly elastic impact with a very heavy head, but it gives you the idea. Actual launch angle is different due to friction, etc. The key is that you have to add the speed and direction of the clubface to the ball rebound vector.