Need help on Gamma

[drewyallop]

I think I have read in someone's paper that the twisting torque (Gamma) contributes significantly to clubhead acceleration. I can't remember where (I think MacKenzie). I would be grateful for a link.

I think I also remember a paper stating that gamma torque plays a relatively insignificant role in clubhead acceleration (Nesbit).

I could be wrong on both counts but it is bugging me since gamma seems to be relevant to the ROC discussion.

Drew

 

[Michael Finney]

According to Nesbit, the scratch golfer in his study gained ~4 mph from his personal "gamma"....everyone gains from their "gamma" - some more than others - the scratch's "gamma" at impact was recorded at 1200 deg/sec....of course this is the handle and it was recorded at 180 hz.....

going further...."The gamma angular component indicates the rolling motion about the long axis of the club shaft and are important in squaring up the club face for impact. Figures 13 and 14 reveal that the gamma motion is significant yielding angular velocity values that are approximately half of that for the alpha component."

I'll check on Mackenzie

 

[Michael Finney]

This just in from a guy with 500 more hz than dr.nesbit had.......the lead and droop turn the closing face into a ""zero sum game" relative to club head speed...think center shafted putter going really fast......so the 3% gain from the gamma angular velocity may be overstated......

 

[bluebird]

So if one leaves 3% out, you loose 0% ?

 

[Michael Finney]

So if one leaves 3% out, you loose 0% ?

glass half empty, glass half full.....

i guess the take home is that because of the shaft bending modes that the face closing cannot add appreciable speed to the club head.....again, this is coming from someone who is in a position to know and has the best tools to measure these things - does that make him and his measurement program 100% correct - who really knows? - but i would tend to listen....

 

[drewyallop]

This just in from a guy with 500 more hz than dr.nesbit had.......the lead and droop turn the closing face into a ""zero sum game" relative to club head speed...think center shafted putter going really fast......so the 3% gain from the gamma angular velocity may be overstated......

Thank you Michael. Clubhead dynamics gets, daily, more complex and interesting.

 

[Bigwill]

Could the 3% gain be coming not from the actual rotation of the clubface or clubshaft itself, but from the fact that when the good golfer increases the rotation of his forearms during the execution of his swing, he also increases the rate at which he advances the clubhead?

 

[bluebird]

glass half empty, glass half full.....

i guess the take home is that because of the shaft bending modes that the face closing cannot add appreciable speed to the club head.....again, this is coming from someone who is in a position to know and has the best tools to measure these things - does that make him and his measurement program 100% correct - who really knows? - but i would tend to listen....

Thanks Michael. Do you have any thoughts about Bigwill's idea? My take would be that since there could be an angular component involved,at the hands or wrists, that clubhead velocity would be increased by some multiple of each degree/second, produced by the hands?

 

[art]

Dear Bigwill,

Sorry, this is a thread breaker, but your PM is full, and my answer can not get thru.

art

 

[Bigwill]

ok.

 

[grahler]

Seems to me given the definition of gamma that the rotation of the face could not increase speed significantly because the face is quite close to the center of rotation.
The way I think about it is to think about trying to hit a ball by simply rotating the shaft. I doubt you could hit it far.
Seems like Michael F. makes a lot of sense.

 

[dbl]

Not sure if you saw the below thread and Brian's Video in page 5, but gamma helps to increase alpha

http://www.brianmanzella.com/golfin...tes-most-clubhead-speed-now-w-p5-video-5.html

 

[spktho]

Seems to me given the definition of gamma that the rotation of the face could not increase speed significantly because the face is quite close to the center of rotation.
The way I think about it is to think about trying to hit a ball by simply rotating the shaft. I doubt you could hit it far.
Seems like Michael F. makes a lot of sense.

Don't forget the shaft droop in the impact area lines the center of gravity of the clubhead up with the shaft too--center shafted putter analogy.

 

[Brian Manzella]

This was all covered in much greater detail in the rate of closure thread........