"Gyroscopic Effect"

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NYKnuckleballer
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"Gyroscopic Effect"

Post by NYKnuckleballer » Thu Oct 25, 2007 3:09 pm

Is there such a thing as a "gyroscopic effect" wherein a high backspin to sidespin ratio keeps the ball straighter? Or, is this merely a byproduct of hitting below the ball's equator reducing the likelihood of sidespin.

Later,
David

fschmidberger
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Post by fschmidberger » Fri Oct 26, 2007 5:55 am

Hi David,

If you increase the loft for a given clubface angle you will increase the backspin (which is obvious) and decrease the side spin (which may not be that obvious). The decrease of sidespin has nothing to do with "backspin counters sidespin", the decrease just comes from the changed impact geometry.

Actually backspin and sidespin aren't two seperate things. The ball spins around an axis and this axis may be horizontal (backspin only) or tilted (backspin and sidespin). The aerodynamic force that we call "lift" is always perpendicular to the spin axis (and perpendicular to the velocity vector). So, if the spin axis is horizontal, there is no force component acting sideways on the ball. But if the spin axis is tilted there is a sideways component of the lift force.

So, no I don't think there is a "gyroscopic effect" that keeps the ball straighter. It's just a question of how much the spin axis is tilted.

Cheers
Frank

NYKnuckleballer
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Post by NYKnuckleballer » Fri Oct 26, 2007 5:44 pm

fschmidberger wrote:Hi David,

If you increase the loft for a given clubface angle you will increase the backspin (which is obvious) and decrease the side spin (which may not be that obvious). The decrease of sidespin has nothing to do with "backspin counters sidespin", the decrease just comes from the changed impact geometry.

Actually backspin and sidespin aren't two seperate things. The ball spins around an axis and this axis may be horizontal (backspin only) or tilted (backspin and sidespin). The aerodynamic force that we call "lift" is always perpendicular to the spin axis (and perpendicular to the velocity vector). So, if the spin axis is horizontal, there is no force component acting sideways on the ball. But if the spin axis is tilted there is a sideways component of the lift force.

So, no I don't think there is a "gyroscopic effect" that keeps the ball straighter. It's just a question of how much the spin axis is tilted.

Cheers
Frank
Good stuff Frank. The reason I'm asking is because of a small company named e21. Here is an excerpt from a recent article:

http://money.cnn.com/news/newsfeeds/art ... 319068.htm

Pertinent part is this:

"Element 21-engineered.....will keep ball flight on course in a precise direction initiated at launch, even in very windy conditions. The golf ball cuts through shifting air masses because of centrifugal force generated parallel to the line of the launch. This "gyroscopic" effect has been engineered into hybrids and irons utilizing Element 21 Scandium Technology, by minimizing the ratio of the sidespin to the backspin of the golf ball in flight. This is one of the most unique features of the hybrids and iron clubs using Element 21 Scandium Technology, and provides unprecedented accuracy even on windy days.

Once a golfer hits a ball, the ball has been given speed, direction and spin. The spin of a golf ball has two components: a sidespin and a backspin. By controlling the spin and spin ratios, the accuracy and distance are maintained even in most difficult playing conditions. This effect will be illustrated and explained in an Element 21 Scandium Technology infomercial.

Player testing (during the Wealth Expo in New York on September 19-21, 2007) using Element 21 Scandium Technology and recorded by the Zelocity Pure Launch Monitor demonstrated spin ratios as low as 17-rpm sidespin over 2500-rpm backspin. The graphite shafted clubs of major manufacturers demonstrated on average of 250-rpm sidespin to 2200-rpm backspin. On a slice or a draw the sidespin of a golf ball is over 500 rpm."


I wish they mentioned launch angle on this one, might provide some clues. Thinking that possibly the lighter scandium alloy lowers the COG and allows the ball to "walk up" the face a bit more, creating more backspin with less axis tilt? Any thoughts or do you think this is all marketing bluster?

Later,
David

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Post by fschmidberger » Fri Oct 26, 2007 6:19 pm

David wrote:Any thoughts or do you think this is all marketing bluster?
Well, yes I think it's just marketing bluster. But I'm very interested what Dave thinks about it.

Frank

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Post by dtutelman » Mon Oct 29, 2007 4:25 pm

fschmidberger wrote:
David wrote:Any thoughts or do you think this is all marketing bluster?
Well, yes I think it's just marketing bluster. But I'm very interested what Dave thinks about it.
I agree that it's most likely marketing bluster.

I can point to several things that, while not necessarily disproving the statement, heightens my skepticism:
  1. The announcement is not in a golf journal. It's in money.cnn.com. So they are in selling mode, not in serious technical mode. BTW, their main web site also seems far more selling mode than anything else. Lotsa' gloss, very little substance, and hard to navigate to find out (because they have all sorts of pretty animation instead of snapping from page to page).
  2. The only thing that is scandium about the whole thing is the shaft. They imply that there is something "element-21" about the clubhead, and even the ball. Not true. It's just the shaft.
  3. Even the shaft isn't made of scandium. That would be WAY too expensive. It's aluminum, with a little scandium alloyed in. That gives the aluminum a bit more strength and internal uniformity. But that's what anything alloyed into aluminum is for. Ignore their bluster, and think of the shaft as made from one of the better aircraft-grade aluminums -- because that's what it is.
  4. I have done profiles of a set of E-21 shafts. They were made for a Nationwide Tour pro, and his custom clubmaker suggested I measure the hell out of the shafts before he made up the set. I did. I also took the same measurements on that pro's existing set. (Dynamic Gold X-flex) Comparing the profiles suggested that the set with E-21 shafts would cause shots to balloon more than the Dynamic Golds. Later, he got back to me; they did balloon more.
  5. All of which means it doesn't surprise me that whatever tour success they can point to has been on the senior tour. The older players with less clubhead speed would not have the same problem with ballooning. Moreover, the improved damping of aluminum (compared with steel) would probably be easier on aging joints.
  6. Finally, we get to the claim of "gyroscopic effect". The only thing in the whole system that acts as a gyroscope is the ball. The ball is given an initial spin by the club at impact. Frank described very well how that spin can be characterized. The only thing that gyroscopic effect will do is keep the axis of spin constant, at whatever angle the club imparted to it. If it imparted a lot of sidespin, then the gyroscope will ensure that the proportion of sidespin to backspin remains as it was.
Back to our regularly scheduled programming -- like a new article on ShaftLab that I'm putting up on my site today.

Cheers!
DaveT

NYKnuckleballer
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Post by NYKnuckleballer » Mon Oct 29, 2007 11:08 pm

dtutelman wrote: The only thing that gyroscopic effect will do is keep the axis of spin constant, at whatever angle the club imparted to it. If it imparted a lot of sidespin, then the gyroscope will ensure that the proportion of sidespin to backspin remains as it was.
Good stuff Dave. I'm not sure if you were completely clear though. If you had a chance to invest in this company, you would? :lol:

I actually bought a few of the shafts and put them in play my last couple rounds. I wouldn't notice the ShokBlock if it weren't touted. I think sometimes I feel less vibration than I would normally. I don't generally get sore joints with regular steel shafts so I'm probably not a good test subject.

They claim they hit farther. I haven't seen that. Consistency and improved dispersion. Hard to tell. A bad swing is a bad swing.

They look cool...like Project X stepless shafts but darker in color. In my hands, they have been low launch. They seem all right but not really any different than less expensive shafts.

Thanks for the advice Dave,
Dave

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