birdie_man
New
I think it's funny!
CALL ME GROG
!!!
CALL ME GROG
!!!
Sustaining the line of compression
- Thread starter mandrin
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Tom Bartlett
Administrator
Brian's use of BOLD TYPE is because his Great Great Grandmother (who has been on the edge of her seat following this thread) lives in Canada and she has poor eyesight (as you can imagine) so he types big so she can see it way down here in Louisiana.
Seriously, he typed bold because he was answering in between your quotes and used bold so people can easily see his answers. There is no yelling here. We are a kind and gentle folk.
Curious to know your response to his comments as is, I'm sure, the rest of the viewing audience.
Peace, love, dope.
Seriously, he typed bold because he was answering in between your quotes and used bold so people can easily see his answers. There is no yelling here. We are a kind and gentle folk.
Curious to know your response to his comments as is, I'm sure, the rest of the viewing audience.
Peace, love, dope.
Brian Manzella
Administrator
The 100-to-nothing thng is "Manzella-ese."
Just trying to be funny, Mandrin.
But, as others can see, the SFTPS experiemnt wouldn't make a C- at Tulane.
Just trying to be funny, Mandrin.
But, as others can see, the SFTPS experiemnt wouldn't make a C- at Tulane.
golfbulldog
New
how much does a golf robot cost for hire?
4000 members on this site... all of whom are here because of search for ideal impact conditions... there must be some skilled club builders here who would relish the challenge of building such a hinged club... this experiment needs to be done ... "I believe that this nation should commit itself to achieving the goal, before this decade is out..." so said JFK, "The greater our knowledge increases, the greater our ignorance unfolds."...
I can hear some of you saying "no, it's too tough a challenge..." and yet the great man had still more to say " ... do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too. "
He was your President, do not let him down!!
Repeat the experiment with robot, high speed camera, launch monitor etc... I , as a Brit, am happy to hand over the baton from my scientific forefathers of "SFTPS" fame and allow you high tech "yanks" to take all the glory!! Go forth... Brian set up the Paypal so we can contribute to the fund. Get your mates in the business to give us time on the robot... The "truth" of science is that experiments can , and should be, repeated to verify their findings. If it can't be repeated it may not be true!!
4000 members on this site... all of whom are here because of search for ideal impact conditions... there must be some skilled club builders here who would relish the challenge of building such a hinged club... this experiment needs to be done ... "I believe that this nation should commit itself to achieving the goal, before this decade is out..." so said JFK, "The greater our knowledge increases, the greater our ignorance unfolds."...
I can hear some of you saying "no, it's too tough a challenge..." and yet the great man had still more to say " ... do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too. "
He was your President, do not let him down!!
Repeat the experiment with robot, high speed camera, launch monitor etc... I , as a Brit, am happy to hand over the baton from my scientific forefathers of "SFTPS" fame and allow you high tech "yanks" to take all the glory!! Go forth... Brian set up the Paypal so we can contribute to the fund. Get your mates in the business to give us time on the robot... The "truth" of science is that experiments can , and should be, repeated to verify their findings. If it can't be repeated it may not be true!!
shortgamer
New
Okay I have a serious question for Mandrin, if the clubhead doesn't need to be attached to the head at impact then why does a softer flex profile shaft launch the ball with more velocity than one with a stiffer profile? Or is this a totally different subject?
Brian Manzella
Administrator
Our first Podcast in a long time will shed some light on this subject.
Brian Manzella
Administrator
Here is the FACTS:
I asked Bob Bush at the First PGA Summit:
Al things being equal, 100 MPH Clubhead Speed, same head, center contact, etc. etc., stiff shaft or regular shaft hits the ball the farthest.
Mr. Bush : Stiff
Go ahead mandrin, say Bush doesn't know....I know you will
I asked Bob Bush at the First PGA Summit:
Al things being equal, 100 MPH Clubhead Speed, same head, center contact, etc. etc., stiff shaft or regular shaft hits the ball the farthest.
Mr. Bush : Stiff
Go ahead mandrin, say Bush doesn't know....I know you will
The way we launch a golf ball is through collision.This falls under the conservation of momentum law.In a collision,the momentum(mass x velocity) lost by the clubhead is gained by the ball.In simple terms,the more clubhead velocity is lost at impact,the harder the ball is hit.
What you are decribing is pushing a ball,in which case separation velocity needs to be high.
When I hit my best drives,I feel the shaft firmly stressed at impact.Why do I feel the stress?Because the clubhead has slowed down a bunch but my hands are still driving forward.
mandrin
New
I have spent a fair amount of time explaining in various ways that one can not resist the deceleration of the clubhead, using the clubshaft. There is however not a very warm response, to say the least. 
I will use arguments each and every one on this forum can verify from himself. So, we will use only Newton’s laws and some high school calculus. Hence everybody can use his calculator and simply verify for himself. [8D]
For those who say - mandrin you are full of beans, I really feel keeping the club mashing against the ball - just a few facts.
Impact duration, about 0.0005 sec.
Impact impulse to travel up the shaft to the hands, about 0.0007 sec
Signal from hands to brain, about 0.010 sec
Reaction form brains to hands, about 0.30 sec
Hence the ball will be already away about 2 ft away before we are even aware.
And will have traveled about 50 ft before we can do anything.
Total reaction time is about 600 times the impact interval.
Feel and real, this strange mysterious couple, mystifying so many people. [)]
Enter here, have fun, but be aware, life will never be the same anymore.
I will use arguments each and every one on this forum can verify from himself. So, we will use only Newton’s laws and some high school calculus. Hence everybody can use his calculator and simply verify for himself. [8D]
For those who say - mandrin you are full of beans, I really feel keeping the club mashing against the ball - just a few facts.
Impact duration, about 0.0005 sec.
Impact impulse to travel up the shaft to the hands, about 0.0007 sec
Signal from hands to brain, about 0.010 sec
Reaction form brains to hands, about 0.30 sec
Hence the ball will be already away about 2 ft away before we are even aware.
And will have traveled about 50 ft before we can do anything.
Total reaction time is about 600 times the impact interval.
Feel and real, this strange mysterious couple, mystifying so many people. [
)]Enter here, have fun, but be aware, life will never be the same anymore.
Mandarin: The intent to resist the resistance of the ball by applying an accelerating force is there before contact is made. You make it look like the actual contact initiates the application of an additional force. If that were the case I would agree with you.quote:Originally posted by mandrin
I will use arguments each and every one on this forum can verify from himself. So, we will use only Newton’s laws and some high school calculus. Hence everybody can use his calculator and simply verify for himself. [8D]
For those who say - mandrin you are full of beans, I really feel keeping the club mashing against the ball - just a few facts.
Impact duration, about 0.0005 sec.
Impact impulse to travel up the shaft to the hands, about 0.0007 sec
Signal from hands to brain, about 0.010 sec
Reaction form brains to hands, about 0.30 sec
Hence the ball will be already away about 2 ft away before we are even aware.
And will have traveled about 50 ft before we can do anything.
Total reaction time is about 600 times the impact interval.
Feel and real, this strange mysterious couple, mystifying so many people. [
Enter here, have fun, but be aware, life will never be the same anymore.
golfbulldog
New
Quote ( from mandrin page that is marked "here")
"How is the golfer thought to resist deceleration of the clubhead through impact? Applying force onto the ball through the shaft.
How do you apply force onto the ball using the shaft? Torquing the shaft, using the hands , bending the shaft.
Is that the only possible way to prevent deceleration of clubhead? Yes, it is the only connection between golfer and clubhead."
2-E TGM quotes:-
"Speed ( centrifugal pull) and prestress( acceleration) stiffen the clubshaft for consistent ( minimum to maximum) resistance to impact deceleration. Treat that "heavy feel" of "clubhead recovery" after impact as though it were all impact, even though the ball is actually long gone"
Dear Mandrin, I believe that Hue is correct.
See that I quote Homer Kelly's work merely to show that TGM does not advocate what you claim it does , namely "How do you apply force onto the ball using the shaft? Torquing the shaft, using the hands , bending the shaft". Homer knew the ball "was long gone" by the time impact was felt.
I am not saying that your calculations regarding shaft deflections are incorrect ( i will read later) nor am I saying that TGM does not think that shaft bend is important but you accuse TGM of achieving that shaft bend incorrectly.
SFTPS uses your reaction time calculation ( chapter 22 page 145) to argue that the golfer can not actively alter impact due to "hand reaction to impact". I do not think TGM ever makes this claim, rather it goes on about hands being clamps etc... not active just clinging on etc.
Remember, I like science and scientific experimantal evidence as i presume you do too. I am all for doing the hinged clubhead experiment again!! but doing it better - more accurately and publishing actual results with statistics rather than conclusions on their own.
TGM followers - please check out these references ( i am sure most of you know this stuff but think about it in the context of this specific discussion)
http://www.bbc.co.uk/schools/gcsebitesize/physics/forces/fallingobjectsrev2.shtml
http://homepage.ntlworld.com/neil.haggath/apollopage6.html
Remember gallileo intuitively ( like Homer Kelly) got it right but could not prove it so he got persecuted.
Newton worked it out but did not have video/internet/tv to show the beauty of experiment to the masses ( like the SFTPS brits) BUT
it took Apollo mission ( ie USA ) to demonstrate the beauty of physics with the hammer and feather experiment on the moon - demonstrating most of the physics that they had relied on to get there in the first place. They, like TGM leaders, knew "they were right" but still did the basic experiment to show they were right and pay "homage" to the guys ( Gallileo and Newton). They had nothing to fear from the results and everything to gain!!
Golf tuition is in the same process, TGM leaders think they have got the scientific geometrical answer but need to show the world they are right and get the physics evidence. Hence all my JFK/ Apollo references in previous message.
Seeing is believing... do the experiment again and lets not waste another 9 pages on conjecture and subjective opinion until we have some facts!!
"How is the golfer thought to resist deceleration of the clubhead through impact? Applying force onto the ball through the shaft.
How do you apply force onto the ball using the shaft? Torquing the shaft, using the hands , bending the shaft.
Is that the only possible way to prevent deceleration of clubhead? Yes, it is the only connection between golfer and clubhead."
2-E TGM quotes:-
"Speed ( centrifugal pull) and prestress( acceleration) stiffen the clubshaft for consistent ( minimum to maximum) resistance to impact deceleration. Treat that "heavy feel" of "clubhead recovery" after impact as though it were all impact, even though the ball is actually long gone"
Dear Mandrin, I believe that Hue is correct.
See that I quote Homer Kelly's work merely to show that TGM does not advocate what you claim it does , namely "How do you apply force onto the ball using the shaft? Torquing the shaft, using the hands , bending the shaft". Homer knew the ball "was long gone" by the time impact was felt.
I am not saying that your calculations regarding shaft deflections are incorrect ( i will read later) nor am I saying that TGM does not think that shaft bend is important but you accuse TGM of achieving that shaft bend incorrectly.
SFTPS uses your reaction time calculation ( chapter 22 page 145) to argue that the golfer can not actively alter impact due to "hand reaction to impact". I do not think TGM ever makes this claim, rather it goes on about hands being clamps etc... not active just clinging on etc.
Remember, I like science and scientific experimantal evidence as i presume you do too. I am all for doing the hinged clubhead experiment again!! but doing it better - more accurately and publishing actual results with statistics rather than conclusions on their own.
TGM followers - please check out these references ( i am sure most of you know this stuff but think about it in the context of this specific discussion)
http://www.bbc.co.uk/schools/gcsebitesize/physics/forces/fallingobjectsrev2.shtml
http://homepage.ntlworld.com/neil.haggath/apollopage6.html
Remember gallileo intuitively ( like Homer Kelly) got it right but could not prove it so he got persecuted.
Newton worked it out but did not have video/internet/tv to show the beauty of experiment to the masses ( like the SFTPS brits) BUT
it took Apollo mission ( ie USA ) to demonstrate the beauty of physics with the hammer and feather experiment on the moon - demonstrating most of the physics that they had relied on to get there in the first place. They, like TGM leaders, knew "they were right" but still did the basic experiment to show they were right and pay "homage" to the guys ( Gallileo and Newton). They had nothing to fear from the results and everything to gain!!
Golf tuition is in the same process, TGM leaders think they have got the scientific geometrical answer but need to show the world they are right and get the physics evidence. Hence all my JFK/ Apollo references in previous message.
Seeing is believing... do the experiment again and lets not waste another 9 pages on conjecture and subjective opinion until we have some facts!!
You are feeling the 192 gm clubhead being stunned by the 46 gm ball. A smaller scale version of a 4000 lb pickup going 100 mph and hitting a 1000 lb cow, according to mandrin. But, assume that the pickup has long spikes on the tires - then the pu slows down less, and the cow, much more thoroughly compressed, is thrown a greater distance.
In the golf example, you can use the ground, and it's connections to the clubhead, to make that bunch significantly smaller than it would be if the clubhead were merely a free body through impact.
There were at least one, and probably two fundamental problems in that experiment. The first, assuming the hinge was a true free hinge, is that the hinged club has a mechanical advantage over a normally shafted one - the hinge is an extra accumulator. But even with that advantage, the hinged club didn't match the performance of the normally shafted one. Which brings us to the real problem - the swinger of the club. Even in the late 60s, 210-215 yds with a persimmon 2-wood was not representative of tour distances. This indicates that the golfer in the experiment didn't use the advantage of his connection to the ground, and may have even been a flipper.
bts
New
Ok, it's time to get back to the "scientist"'s original assumed (because he was not sure if the head came off prior to, during or after impact) simple question. BTW, this "scientist" like those, whom he believe strongly, treated a head attached to the shaft with a free hinge as one completely detaching from the shaft.quote:Originally posted by mandrin
on the tenth hole.
Dave Kelly at his first participation this weekend in a PGA event - the Ford Championship at Doral - had an interesting experience
The head of his driver, a Nike, Sasquatch, completely separated from the shaft and was found 70 yards further away in the fairway. The driving distance still quite interesting - 300 yards.
My simple question for the TGM experts - how did he maintain the line of compression through impact with a head completely detaching from the shaft?
Could it just be that this is a clear confirmation of the laboratory tests done by a group of eminent English scientists behind “Search for the Perfect Swing”. [
Here is a simple "clip test", to hopefully answer his question:
A clipping device (garden scissor/trimmer) can be placed under corresponding setups, so that the far end of shaft closest to the head can be clipped off (which mimics exactly one completely detaching from the shaft) "prior to, at contact, during (early, middle and late) impact, at separation and after impact. Same experimental condition, including head, shaft, approaching speed, lag (effective mass or shaft bent) and acceleration rate (thrust), are taken, of course. All measurable and observable parameters are also taken.
A cork or rubber gap, of which resistance against the passing shaft can be adjusted to that of the clipper, can be used for control.
With enough shafts, different swing procedures (including hitting, swinging, switting and hacking), shafts and release types can also be tested accordingly.
FORE CLUBHEAD!!!!!!
palmreader
New
quote:Originally posted by mandrin
I have spent a fair amount of time explaining in various ways that one can not resist the deceleration of the clubhead, using the clubshaft. There is however not a very warm response, to say the least.
I will use arguments each and every one on this forum can verify from himself. So, we will use only Newton’s laws and some high school calculus. Hence everybody can use his calculator and simply verify for himself. [8D]
For those who say - mandrin you are full of beans, I really feel keeping the club mashing against the ball - just a few facts.
Impact duration, about 0.0005 sec.
Impact impulse to travel up the shaft to the hands, about 0.0007 sec
Signal from hands to brain, about 0.010 sec
Reaction form brains to hands, about 0.30 sec
Hence the ball will be already away about 2 ft away before we are even aware.
And will have traveled about 50 ft before we can do anything.
Total reaction time is about 600 times the impact interval.
Feel and real, this strange mysterious couple, mystifying so many people. [
Enter here, have fun, but be aware, life will never be the same anymore.
Mandrin,
I think your calcs are correct to the point where the force on club head is 1324 lb and deflection of the head is -0.15in, then I lost your argument. You brought in a "measured stiffness for my driver is 140N/m". What is this stiffness? This is equalt approx. 10 lb/ft. If 10 lb can deflect something one foot, you are talking about very soft spring action. How is this stiffness measured (what is this stiffnes?)? Then if you look at your numbers, assume the driver length is 45 inches, distance between fulcrum (left hand) and force (PP#3) is about 2 inches, and knowing the modulus and moment of inertia of the shaft (EI), one can calculate the moment that need to be applied by the left hand (fulcrum, it is not a hinge with M=0),and the primary force at PP#3. That is the force that resist the deaccelration of the club. Where do you get this 0.12 lb???????
Brian Manzella
Administrator
....5 EXTRA yards on hacker's (with leakage) 2-wood shoots, with a 60's era ball....
Brian Manzella
Administrator
Right on Joe.
But, I think the golfer has NO influnence IN the interval, or DURING the interval.
The golfer has control OVER the interval.
But, I think the golfer has NO influnence IN the interval, or DURING the interval.
The golfer has control OVER the interval.
By influence in the interval, I don't mean that he's adding something in the interval. Some golfers come into impact in such a way to make the clubhead less prone to velocity loss in the impact interval than others. So, the clubhead is not just a free body. There's more to it than just clubhead speed at impact.
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