|
Post by imperfectgolfer on Oct 21, 2012 8:42:55 GMT -5
See this Jeffy thread. jeffygolf.com/showthread.php?481-Video-Kelvin-on-Impact-CurvatureVery interesting results. This type of research may give Trackman fanatics (like BM and cwdlaw223) the fits because it calls into question the validlity of Trackman's theories/measurements! I have even noted that cwdlaw223 posted a comment and then presumably removed it because post #4 (at 6:46pm) is blank. I have one question - how high is the camera mounted above the ball, and what is the effect of parallax error when the clubface is not at impact (presuming that the camera is mounted vertically above the ball)? Jeff.
|
|
|
Post by imperfectgolfer on Oct 25, 2012 9:42:36 GMT -5
I have been following the debate between BM and Jeffy regarding the Phantom videos. Unfortunately, I have been banned from both forums so I cannot join the debate.
There is one major problem I have with TM and it relates to this BM-claim (in italics).
"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."
TM gives different readings for the face orientation angle in those three scenarios depending on whether there was a center strike or off-center strike (heel or toe strike) - presuming that the clubface orientation was zero at impact.
But, how does Fred Tuxen know that the clubface orientation was zeroed-out at impact if TM cannot see/measure the clubface orientation angle? Does he have another "golf standard" measuring device that can determine that the clubface orientation angle was really zero at impact?
Another question - BM talks about the path of the COG of the clubhead being important, and I cannot understand why - seeing that the ball should only be presumably influenced by the front of the face orientation angle and front of face path at impact. Can anybody enlighten me?
Also, if the COG of the clubhead is important in path measurements, how does TM measure the COG path (rather than the path of the sweetspot of the clubface)?
Jeff.
|
|
|
Post by imperfectgolfer on Oct 25, 2012 11:17:16 GMT -5
See this page of the BM-forum thread. www.brianmanzella.com/golfing-discussions/17764-high-speed-impact-video-part-1-manzella-response-6.htmlcwdlaw223 wrote-: " 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." He presumes that Trackman's calculations are correct, but how can they be correct if it doesn't really see the clubface orientation angle. It presumably makes an assumption about the likely clubface orientation angle - based on the radar-detected ball flight pattern, and it then works backwards to calculate the "apparent" clubface orientation angle (for a presumably centered strike because it doesn't apparently measure the degree of off-center strike). How did cwdlaw2223 not originally realize that these calculations included gear-effect? Did he presume that TM really measured (objectively knew) the "true" clubface orientation angle? Birly Shirly wrote-: " 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." How does he actually know that the clubhead really acts as a free agent? The hinged club experiment described in the "Search for a Perfect Swing" book allowed them to claim that the ball went as far and as straight with a hinged club, but did they include off-center strikes in their testing? Jeff.
|
|
|
Post by imperfectgolfer on Oct 26, 2012 16:53:13 GMT -5
BM doesn't understand TGM mechanics. See this thread and BM post. www.brianmanzella.com/golfing-discussions/17770-just-reminder-while-back.htmlBM wrote-: " Fredrik Tuxen said to me today in a 30 minute Skype conversation:
A perfectly straight ball (no side-spin) would actually have an impact have about about a 0.4° closed face at mid-impact interval (the point near maximum compression when the ball gets its programming) and a 0.7° inside-out path. These numbers are not 0.0° because of a gear-effect-like action on the face to the ball (more on that in a second). On an normal shot with about 0.8° of face closure during the entire impact interval, that would mean the club would have first contact with the ball with the face AT 0.0° so that halfway through the interval, the clubface would be 0.4° closed.............So what?............So THIS!........(more Tuxen) If the golfer did everything EXACTLY like the straight ball, except had HALF the amount of closure during the interval, so that the face would be 0.2° closed (0.2° MORE OPEN THAN THE STRAIGHT BALL) the ball would slightly draw!!!!!! Start slightly right and DRAW!!." So.....
Lets say that the TGM THEORETICAL idea of "horizontal hinge action" produced the straight ball (it can) and the "angled hinge action" produced the half amount of closure in the example above (just about correct if you do some math) then TGM would be EXACTLY BACKWARDS!!!BM doesn't understand the difference between a HH action and an AH action because it doesn't apply to the impact interval, and it only applies to the followthrough phase between P7 and P7.5. In other words, during that entire period of about two feet of clubface travel, the clubface is rotating slightly more closed when using a HH action rather than an AH action. I believe that there should be no difference in the degree of rotation in the immediate impact zone (between P7 and P7.1) because the clubface should not be significantly rotating during that time period. If a golfer squares the clubface by P6.9, then he should keep it square to the target through the impact interval and only start rotating the clubface after the ball has already left the clubface - whether he uses an AH action or a HH action. Through impact, he should have a stable clubface that doesn't rotate (and he should be doing what KM calls drive-holding). Also, Fred Tuxen may believe that a slower rate of clubface rotation during the impact interval promotes a draw ball flight (rather than a straight ball flight), but he has not provided a coherent explanation that either satisfies me (or Jeffy). Can anybody explain why the ball should draw under those conditions? Jeff.
|
|
|
Post by imperfectgolfer on Oct 27, 2012 7:52:27 GMT -5
Advice to KM - repeat your experiments while simultaneously using a Trackman device so that you can compare the Trackman readings to the measurements obtained by the Phantom camera. Also, consider placing a lined grid on the hitting mat so that there are reference points for the ball-target line and desired line of flight for a straight shot.
Jeff.
|
|
|
Post by richie3jack on Oct 29, 2012 12:53:25 GMT -5
I would also suggest using a spray on the clubface so he can see exactly where the ball hit on the face.
3JACK
|
|
|
Post by gmbtempe on Nov 9, 2012 14:48:40 GMT -5
Advice to KM - repeat your experiments while simultaneously using a Trackman device so that you can compare the Trackman readings to the measurements obtained by the Phantom camera. Also, consider placing a lined grid on the hitting mat so that there are reference points for the ball-target line and desired line of flight for a straight shot. Jeff. I have wondered why this has not happened as well so the results could be compared.
|
|
|
Post by tomdavis76 on Nov 10, 2012 19:06:19 GMT -5
Advice to KM - repeat your experiments while simultaneously using a Trackman device so that you can compare the Trackman readings to the measurements obtained by the Phantom camera. Also, consider placing a lined grid on the hitting mat so that there are reference points for the ball-target line and desired line of flight for a straight shot. Jeff. I have wondered why this has not happened as well so the results could be compared.Wonder no longer. I took delivery of a nice Trackman II with the built-in camera yesterday and will be bringing it to Kelvin's Phantom research-a-thon in Phoenix in early December. You should come by and we'll analyze you!
|
|
|
Post by tomdavis76 on Nov 10, 2012 19:11:22 GMT -5
I have been following the debate between BM and Jeffy regarding the Phantom videos. Unfortunately, I have been banned from both forums so I cannot join the debate. There is one major problem I have with TM and it relates to this BM-claim (in italics). " 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." TM gives different readings for the face orientation angle in those three scenarios depending on whether there was a center strike or off-center strike (heel or toe strike) - presuming that the clubface orientation was zero at impact. But, how does Fred Tuxen know that the clubface orientation was zeroed-out at impact if TM cannot see/measure the clubface orientation angle? Does he have another "golf standard" measuring device that can determine that the clubface orientation angle was really zero at impact? Another question - BM talks about the path of the COG of the clubhead being important, and I cannot understand why - seeing that the ball should only be presumably influenced by the front of the face orientation angle and front of face path at impact. Can anybody enlighten me? Also, if the COG of the clubhead is important in path measurements, how does TM measure the COG path (rather than the path of the sweetspot of the clubface)? Jeff. Not seeing that...
|
|
|
Post by tomdavis76 on Nov 10, 2012 19:19:38 GMT -5
I would also suggest using a spray on the clubface so he can see exactly where the ball hit on the face. 3JACK On it.
|
|
|
Post by imperfectgolfer on Nov 10, 2012 20:16:36 GMT -5
I am delighted that Jeffy is going to run a Trackman device concurrently with a Phantom camera. The results should be interesting!
I am open-minded about the results that will be obtained because I have no horse in the race and I simply want to learn more about how clubface orientation/clubhead path/off-center hits interact to affect the ball flight. However, I can easily imagine that BM is worried because he has a horse in this race!
Jeff.
|
|