High-Speed Impact Video (with Manzella response)
- Thread starter tallathlete
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"to what happens to the ball as a result of the collision." Sorry, I'll reword that as I was writing whilst trying to organise something else:
"what the golf club did to the ball to cause the ball to do what it did and of course what the ball did to the clubhead." Or IOW the impact conditions.
"what the golf club did to the ball to cause the ball to do what it did and of course what the ball did to the clubhead." Or IOW the impact conditions.
Brian Manzella
Administrator
Good one Mike.
Here is the take home......THERE IS NO MAGIC BULLET TO LIMITING FACE ROTATION!!!!!
Better off trying to line up the CoG and the Path.
Next!
Brian Manzella
Administrator
BTW, do you realize there is gear effect on 99.9999999999999999999% of all shots? Just sayin'
Here is a Trackman example for you....
0° Path, 0° Face at first contact, CoG aligned hit: TM reports 0° Path, 0° Face, 0° spin axis
0° Path, 0° Face at first contact, toe side CoG aligned hit: TM reports 0° Path, some amount open "x°" Face depending on how much the face got kicked open, some amount hook spin "x°" spin axis depending on how much the strike tilted the spin axis.
0° Path, 0° Face at first contact, heel side CoG aligned hit: TM reports 0° Path, some amount closed "x°" Face depending on how much the face got kicked closed, some amount slice spin "x°" spin axis depending on how much the strike tilted the spin axis.
None of this would change on a inside-out or outside-in.
birly-shirly
New
Let's take, say, a 30 yard hook with a driver as an example.
Face and resultant path is square - but a toe strike. According to "conventional understanding", how much face rotation would we expect to see whilst the clubface and ball remain in contact?
Face and resultant path is square - but a toe strike. According to "conventional understanding", how much face rotation would we expect to see whilst the clubface and ball remain in contact?
Yes , I know there is always some kind of GE.
Thanks for the examples. They are of course the mega simple examples.
I'm talking more about situations where it gets complicated, like strange combinations of path, face, centredness, CH speed, shaft torques etc which actually result in a similar/identical ball flight and TM report but were cause by wildly different impact conditions primarily as a result of the GE. Or does that never happen?
Thanks for the examples. They are of course the mega simple examples.
I'm talking more about situations where it gets complicated, like strange combinations of path, face, centredness, CH speed, shaft torques etc which actually result in a similar/identical ball flight and TM report but were cause by wildly different impact conditions primarily as a result of the GE. Or does that never happen?
Is it a failure from TM when the reported ball spin axis is a hook and the face is reported open or is it a operator failure when he doesn't understand the reason behind it?
Is it a TM failure when I take 5 heads and a swing robot then making sure that the all is the same including impact is at the same spot for those 5 heads and then see different data? Or was that not again a researcher failing to understand what he was doing?
Is it a phantom failure when again using a swingrobot using head A and then hit again the ball using head B and get two different video's ?
PS : Why do you think the TM fails to accommodate for GE and what do you think the TM should report then in that same scenario that you quoted about David Howell ?
Here is story about an operator that knows how to read the TM data
Frans, thanks for your responses. I don't think TM fails to accommodate GE. And I believe that it is effectively "factored in" as Brian said. I just don't think there is any accuracy regarding the extent of the role GE played in influencing the ball flight. Hence the requirement for operator skill and experience. If everything was measured, any Tom Dick or Harry could use a TM, right?
What I have taken from the conversation is that maybe it is impossible to measure GE as it is influenced by too many variables and that TM is already as close as you can be. Maybe, maybe not. There WILL be a TMIV, of that I am sure.
But, as ever, I'm completely open to any information improves my understanding. That's why I'm here and that's why I'll always owe Brian a debt of gratitude, like everyone who has benefited from this forum.
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Kevin Shields
Super Moderator
The ball spin axis will never tilt as much as the face is said to be closed. So if the ball isn't hooking as much as the the amount the face is closed, you know it was hit off the heel. Again, like Brian said, extremely elementary if you've spent any time on Trackman. Not knocking anyone who hasn't, but the detractors would be better off going to spend some real time on one before doubting so much.
Brian Manzella
Administrator
If I hear the word "measured" on more time.......geez....it is a SUM of many, many, many, many of moments in time.
From Fredrik Tuxen:
"The biggest mistake (on the video) is: gear effect will first show up as a rotation of the club head during the 0.5 ms where there is contact with ball - and primarily it will be around max compression which is significantly shorter time. He is primarily looking on how the club face is behaving before impact relative to impact.
When looking at gear effect it is the rate of rotation that matters while the ball has contact with the ball. The actual amount of rotation is so small during the contact time with the ball, that it will very difficult to see this even with 100.000 fps video."
From Fredrik Tuxen:
"The biggest mistake (on the video) is: gear effect will first show up as a rotation of the club head during the 0.5 ms where there is contact with ball - and primarily it will be around max compression which is significantly shorter time. He is primarily looking on how the club face is behaving before impact relative to impact.
When looking at gear effect it is the rate of rotation that matters while the ball has contact with the ball. The actual amount of rotation is so small during the contact time with the ball, that it will very difficult to see this even with 100.000 fps video."
birly-shirly
New
Brian - I think that answers my question. In 0.0005s, the rate of rotation could be great, but the amount of rotation almost invisible. The face "kicking open" only shows up over a comparatively longer timeframe, ie post impact.
birly-shirly
New
Well, at what point is the rotation visible - and clearly outside of the margin for error for a given picture quality, screen resolution etc?
Suppose you thought you could detect a quarter of a degree of movement during the entire impact interval (which in itself is probably too long). That's still hundreds of degrees of face rotation per second. Pretty square? Pretty stable?
Suppose you thought you could detect a quarter of a degree of movement during the entire impact interval (which in itself is probably too long). That's still hundreds of degrees of face rotation per second. Pretty square? Pretty stable?
mgranato
New
How messed up is it that the origin of this video has only solicited 10 replies from its own following (5 of those from the one person least equipped to authoritatively speak about a functional impact), and here it's gotten 6 pages worth. The video is academically crippled, proven so by the experts’ autopsy. I like poking the efforts of the chronically wrong as much as the next guy, but it seems like we're just keeping something alive that is literally begging to die.
Have mercy, people. Let this thing do what it was destined to do from the start.
Have mercy, people. Let this thing do what it was destined to do from the start.
birlesque, I was referring more to a scenario where the twisting is counteracted very quickly, as stated above, but is obviously still present during the impact interval.
The problem is you cannot "see" the forces on video and what looks "stable" doesn't mean the shot is even playable. Really bad shots are obvious on video. But when the speed goes up, the tolerances for a decent shot go way down. Maybe some high speed cameras could work, but a guy with a phantom and photo shop doesn't cut it. It's truly laughable that someone thinks they can figure out impact without the science/math behind the forces. Trackman does the math/science for us.
Has anyone on this planet, even the haters, ever questioned Trackman's ballflight data? NOPE. Any yet when it comes to Trackman making a calculation it has to be wrong but such person cannot say how wrong it really is and that is lost upon them. I don't deny Trackman could have errors, but how much? .002? .0000005? Not enough for me to trash the machine and avoid the stroke saving benefits.
This all started because the person who used Trackman pulled it out of the box, saw an open face to path and Trackman showed him the ball went left. He didn't understand that Trackman included the gear effect in its face/path calculations (I didn't either) so he presumed it had to be wrong. You can't just pull this machine out of the box and use it like a Coke machine.
Of course, if you can't use Trackman as a teaching tool it must be wrong. Or if your students have horrible disparities between face/path it has to be wrong because that person knows with all of their being and studies that they're right. This happens all the time throughout history when it comes to new technology.
Trackman is the best we have right now.
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birly-shirly
New
birlesque? never mind the rest of your post, you get a smiley from me just for that!
to be honest, I don't think I understand the twisting/counteraction point. "everyone knows" that at impact the clubhead acts like a free agent, but I don't know for how long.
Michael Finney
New
great question - one paul wood could answer easily i assume - but we've bothered him enough recently....
we'll start bothering the guys at loughborough for a time
Just wanted to say, Bmanz claims to be educating the world. Sounds crazy, but I can tell you he is changing the views of golf pros the world over. I suggest that few, if any, in the history of instruction have had such an influence, BUT he is still relatively unknown. Crazy.
Leadbetter changed a lot, but a lot of things he promoted were detrimental.
Leadbetter changed a lot, but a lot of things he promoted were detrimental.
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