Plane as a straight line concept?
- Thread starter wulsy
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Hi, I've just read this and subsequently joined the forum to ask.....
Why not? Not even as a visual aid?
..and, ...what will you use instead?
In my understanding, the D-plane is between the vectors involved in the initial ballflight. If so, then D-plane can still exist.
+1
D plane is just at impact. And of course Brian has define a U plane down there as well.
The Dplane "to come" "exists" when you are at the top of the downswing, but won't really have much meaning until you bring the club down into the ball and create/affirm the impact alignments for the D plane.
D plane is just at impact. And of course Brian has define a U plane down there as well.
The Dplane "to come" "exists" when you are at the top of the downswing, but won't really have much meaning until you bring the club down into the ball and create/affirm the impact alignments for the D plane.
I think that geometric/Euclidean vectors are inseperably connected with planes and that the introduction of curvature requires the introduction of tensors to accurately represent the forces in the golf swing. Not being a mathematician, I cannot claim this with any certainty.
However, all that aside, the basic question is how accurately Tracky and Flighty measure the forces. Lets assume that what the ball does is very consistent with what Tracky and Flighty predict, then the measurement is accurate enough. To check this you would have to "blind" the device so that it can't see the ball flight and ask it to predict the result based on the measurement of the club's movement and check for any inconsistencies. If they were significant, its back to the drawing board. But I'm sure that the developers have done this or something similar and are aware of the degree of inconsistency. Anyone want to tell us how much it is
However, all that aside, the basic question is how accurately Tracky and Flighty measure the forces. Lets assume that what the ball does is very consistent with what Tracky and Flighty predict, then the measurement is accurate enough. To check this you would have to "blind" the device so that it can't see the ball flight and ask it to predict the result based on the measurement of the club's movement and check for any inconsistencies. If they were significant, its back to the drawing board. But I'm sure that the developers have done this or something similar and are aware of the degree of inconsistency. Anyone want to tell us how much it is
I asked a similar question several days ago and didn't get an anwer...
"If you use a hula hoop to describe the VSP and swing direction to keep it simple, than what is the actual shape of the path the sweetspot is travelling? Is it a perfect sphere and can it change direction from its original path? Its an important question because if I take a hula hoop and start bending it like a pretzel, it's going to have a serious effect on the simplicity of describing the D Plane."
Sounds like hula hoops and straight lines are a pretty simplistic explanation for tracking a clubs movement, is it not?
"If you use a hula hoop to describe the VSP and swing direction to keep it simple, than what is the actual shape of the path the sweetspot is travelling? Is it a perfect sphere and can it change direction from its original path? Its an important question because if I take a hula hoop and start bending it like a pretzel, it's going to have a serious effect on the simplicity of describing the D Plane."
Sounds like hula hoops and straight lines are a pretty simplistic explanation for tracking a clubs movement, is it not?
If you want to see the basic path of the sweetspot, have you seen any of the strobe light photos and movies of swings? I think some were done with Jones and Hogan, for instance.
I would say reverse tumble will make the clubhead path appear more planar, while late tumble and to some degree early tumble, will show how it's not.
Therefore making something overly simple will of course provide bad medicine for those who don't swing the way the planar theorist advocates.
I would say reverse tumble will make the clubhead path appear more planar, while late tumble and to some degree early tumble, will show how it's not.
Therefore making something overly simple will of course provide bad medicine for those who don't swing the way the planar theorist advocates.
mjstrong
New
The d-plane, as we now understand it, does not need a straight plane line to exist. The measurements are taken virtually instantaneously at impact, and during such a small interval that the plane of the club's movement at that instant can be used to form the d-plane, even if the club's actual movement from hip high to hip high doesn't even remotely resemble a plane.
Thanks for the explanation.
Not to try to complicate things, but if a player sets up for a driver and someone re-tees the ball two inches away in any direction, the player will probably reroute the club and try to make the best contact possible and hit the straightest shot possible. If the only thing that matters is impact, then everything else would be irrelevant. The face and path can clearly be manipulated during every swing so unfortunately it still comes back to the one basic tenant to playing great golf...repetition.
Not to try to complicate things, but if a player sets up for a driver and someone re-tees the ball two inches away in any direction, the player will probably reroute the club and try to make the best contact possible and hit the straightest shot possible. If the only thing that matters is impact, then everything else would be irrelevant. The face and path can clearly be manipulated during every swing so unfortunately it still comes back to the one basic tenant to playing great golf...repetition.
Kevin Shields
Super Moderator
Welcome to the forum.
I dont USUALLY use things that provide simplicity by omission...especially in that area.
I wouldnt substitute anything instead.
lia41985
New member
Just like we've gotten away from a lot of The Golfing Machine terminology, can we also draw from the same well of vocabulary as applied to ball and club geometry? How about a sticky for this?: http://thebrandingengine.com/WAMUser/UserFiles/243/File/TrackmanDataReport.pdf
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Actually, lia, Fred Tuxen came out with some new terminology for the Trackman variables - see the October '10 newsletter. Brian started a thread on it a while back.
Was: Vertical Swing Plane. Now: Swing Plane
Was: Horizontal Swing Plane. Now: Swing Direction
Coupla' others may have changed. Spin Axis is still Spin Axis, thank goodness.
Was: Vertical Swing Plane. Now: Swing Plane
Was: Horizontal Swing Plane. Now: Swing Direction
Coupla' others may have changed. Spin Axis is still Spin Axis, thank goodness.
Trackman numbers?
lia41985
New member
Thanks for the heads up. Here it is: http://www.trackman.dk/download/newsletter/newsletter7.pdf
From Trackman Newletter: "In the past, TrackMan needed 15 feet (5 meters) of ball flight to
directly and accurately measure spin rate.
Now using just 10 feet (3 meters) of ball flight, TrackMan is
able to achieve our own industry-leading standard of precision
for measuring spin."
OK, now we're getting somewhere. Tackman data is DEPENDENT on the device "seeing" the ball flight, so it CANNOT predict ball flight based on measuring the movement of the club.
The question is how instant is instant and how much of the bottom of the swing arc is actually measured.?
The definition of Swing Plane from the Newsletter:
"Swing plane (formerly vertical swing plane): a measure of how
vertical the swing is, where a high value represents a very up and
down (steep) swing plane and a low value a relatively flat (to the
ground) arc. More technically, it is the angle made between the
ground and the plane of club head trajectory at the bottom of the
swing arc
Swing direction (formerly horizontal swing plane): the orientation
of the swing arc, relative to the target line, where positive
means to the right, negative means to the left. More technically, it
is the horizontal direction the club head is traveling in at the bottom
of the swing arc"
directly and accurately measure spin rate.
Now using just 10 feet (3 meters) of ball flight, TrackMan is
able to achieve our own industry-leading standard of precision
for measuring spin."
OK, now we're getting somewhere. Tackman data is DEPENDENT on the device "seeing" the ball flight, so it CANNOT predict ball flight based on measuring the movement of the club.
savydan: said:
The question is how instant is instant and how much of the bottom of the swing arc is actually measured.?
The definition of Swing Plane from the Newsletter:
"Swing plane (formerly vertical swing plane): a measure of how
vertical the swing is, where a high value represents a very up and
down (steep) swing plane and a low value a relatively flat (to the
ground) arc. More technically, it is the angle made between the
ground and the plane of club head trajectory at the bottom of the
swing arc
Swing direction (formerly horizontal swing plane): the orientation
of the swing arc, relative to the target line, where positive
means to the right, negative means to the left. More technically, it
is the horizontal direction the club head is traveling in at the bottom
of the swing arc"
From Newsletter: "TrackMan has seen that other
technologies that estimate, rather than directly measure, spin rate
have a margin of error of +/- 1000 rpm on the spin rate. So, if you
assume 2000 or 4000 rpm in the ball flight model, rather than the
“real” 3000 rpm, you would get total distances of 276 yards or 230
yards, respectively (252 and 210 meters). This is a discrepancy
of 46 yards (42 meters)! That margin of error would make the
numbers entirely misleading, resulting most likely in a poor
equipment recommendation."
There's your answer. The discrepancy for Spin Rate is pretty large in "other ball flight models" (competitors'). The fact that they want to measure suggests that its also pretty large in theirs. No data on whether the other parameters have similar discrepancies.
technologies that estimate, rather than directly measure, spin rate
have a margin of error of +/- 1000 rpm on the spin rate. So, if you
assume 2000 or 4000 rpm in the ball flight model, rather than the
“real” 3000 rpm, you would get total distances of 276 yards or 230
yards, respectively (252 and 210 meters). This is a discrepancy
of 46 yards (42 meters)! That margin of error would make the
numbers entirely misleading, resulting most likely in a poor
equipment recommendation."
There's your answer. The discrepancy for Spin Rate is pretty large in "other ball flight models" (competitors'). The fact that they want to measure suggests that its also pretty large in theirs. No data on whether the other parameters have similar discrepancies.
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