There is something funky going on with the clubface post impact to the follow through. Can't quite figure it out yet.......maybe I will over some left over turkey tomorrow.
questions from me about the D-plane (and new fun facts by Brian Manzella on p.3)
- Thread starter golfdad
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There is something funky going on with the clubface post impact to the follow through. Can't quite figure it out yet.......maybe I will over some left over turkey tomorrow.
Hey golfdad, in regards that robot, you've got the d-plane implications wrong. If the robot hits up and square, then the ball will go RIGHT. This is because the true path is to the left while face is straight, thus the dplane tilts to the right. With a driver when hitting up and desiring a straight shot, one has to aim the "path" a bit right so the resultant true path is straight (and of course keep the clubface at the target). Capice?
It's just opposite of irons on the ground before low point, where one aims left else the ball will draw.
ps. I didn't watch the video...in case that robot is doing something unfair/illegal etc.
It's just opposite of irons on the ground before low point, where one aims left else the ball will draw.
ps. I didn't watch the video...in case that robot is doing something unfair/illegal etc.
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Brian Manzella
Administrator
No.
Brian Manzella
Administrator
Facts.
Some little considered D-Plane/U-Plane facts:
• If the face is square to the path, hitting up produces a straight pull, hitting down produces a straight push.
• If the "direction of the swing"/Plane Line/HSP is correctly rotated for a straight-at-the-target resultant path, the face HAS TO BE closed to the DoS/PL/HSP to hit a straight shot on an upward hit, and open to the DoS/PL/HSP to hit a straight shot on an downward. How much? For example on a Driver with a 45° Swing Plane/Plane Angle/VSP, and a 5° upward strike, the face has to be 5° closed to the plane!
• On a straight at the target Direction of Swing/Plane Line/HSP, and a 4° downward strike, angled hinging (face square to the path) will produce a straight push, nowhere near the target!
How do the book literalists sleep at night?
To hit the ball at the target, from this straight at the target Direction of Swing/Plane Line/HSP, and a 4° downward strike, the clubface need to be about 2° closed to the arc/path at mid-impact interval—and the shot would be a draw.
Some little considered D-Plane/U-Plane facts:
• If the face is square to the path, hitting up produces a straight pull, hitting down produces a straight push.
• If the "direction of the swing"/Plane Line/HSP is correctly rotated for a straight-at-the-target resultant path, the face HAS TO BE closed to the DoS/PL/HSP to hit a straight shot on an upward hit, and open to the DoS/PL/HSP to hit a straight shot on an downward. How much? For example on a Driver with a 45° Swing Plane/Plane Angle/VSP, and a 5° upward strike, the face has to be 5° closed to the plane!
• On a straight at the target Direction of Swing/Plane Line/HSP, and a 4° downward strike, angled hinging (face square to the path) will produce a straight push, nowhere near the target!
How do the book literalists sleep at night?
To hit the ball at the target, from this straight at the target Direction of Swing/Plane Line/HSP, and a 4° downward strike, the clubface need to be about 2° closed to the arc/path at mid-impact interval—and the shot would be a draw.
It entirely depends on the perspective you're looking from.
From the perspective of the player, it ALWAYS goes out.
From the perspective of the ball, it can go inside or out.
If the plane line is aimed to the left far enough, you can be striking down on the ball and the clubpath can be to the left from the perspective of the ball. But the clubhead is still going out away from YOU.
IMO, you're trying to learn D-plane the hard way.
IMO, you first have to have a solid understanding of how the D-plane is formed by the True Face and the True Path vectors/lines and how the ball starts on the D-plane and curves away from the Path vector towards the Face vector since the spin axis is perpedicular to the D-plane.
THEN you learn all the Trackman terms like HSP, VSP, hitting down shifts the True Path to the right of the HSP, etc.
Unfortunately, the first part is harder to explain and words, but pretty simple to show visually with a couple of dowel rods representing True Face and Path.
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In the absence of left arm rotation with a lot of releasing of vertical wristcock into impact creating a vertical plane of 90 degrees rotated 90 degrees to the left of body alignment/target line (ie HSP 90 degrees left) there would be no outwards movement even if the clubhead was moving downwards through the impact interval. If this was accompanied by a pulling up using the elbows (as it most likely would be in order to avoid the megadivot) and a lunging down of the head/body (as it would be to try to cancel out the pulling up) there could be an additional contribution (namely, the lunging down) towards downwards striking independent of the wirstcock release. This extreme senario, however unlikely to occur in practice, demonstrates that there are additional factors that need to be factored in, in order to avoid misinterpretation with regard to the D-plane laws.
With increasing rotation of the HSP to the left which would most LIKELY be accompanied by an increasingly steeper VSP you would get closer and closer to the above scenario. And there a lot of golfers who have these basic characteristics in their golfswings.
So whilst for the developed golfswing of the decent player with a VSP within the norm and clear arm rotation (PA3) the basic geometric law that downwards = "considerably" outwards is indisputable, one has to bear in mind that there are factors which, if extreme enough, could cancel this out.
With increasing rotation of the HSP to the left which would most LIKELY be accompanied by an increasingly steeper VSP you would get closer and closer to the above scenario. And there a lot of golfers who have these basic characteristics in their golfswings.
So whilst for the developed golfswing of the decent player with a VSP within the norm and clear arm rotation (PA3) the basic geometric law that downwards = "considerably" outwards is indisputable, one has to bear in mind that there are factors which, if extreme enough, could cancel this out.
Is the important number in all this the 45 degree Swing Plane for it to work this way?
James Marshall (Hogan1953)
New member
"To hit the ball at the target, from this straight at the target Direction of Swing/Plane Line/HSP, and a 4° downward strike, the clubface need to be about 2° closed to the arc/path at mid-impact interval" and would produce a slight draw, right?
HSP 90* left - You'd be kicked off the course.
VSP 90* - true, there's no left or right bias in the downward or upward. Like a Ferris wheel.
Brian Manzella
Administrator
If you didn't get kicked off, you'de have to quit after it got dark and you hadn't finished the first hole
VSP 90*: the outward becomes increasingly insignificanter the steeper the VSP. Any Professor Professor Doctor Doctor of Mathematics out there could work out (with some difficulty) what kind of mathematical relationship exist between the left bias HSP with the steepness of the VSP together with the low point determined by shaft angle together with low point determined by other factors (eg lunging/dipping) together with face angle determined by shaft/lie angle together with face angle determined by other factors (eg twisting). Then you would have to factor in the angular speed of the club relative to the shoulders and the arms. No, I'm not seriously suggesting this can be worked out, I just want to make the point that maybe its not quite as simple as x* downwards = y* outwards and requires a thereof dependent resultant relationship between path and face every time with no exeptions.
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Yes, if you're being exact.
Imagine a Ferris wheel on the target line hitting a ball to the target.
A normal ferris wheel has a VSP of 90*. No left or right bias in the up or down.
Now tip the ferris wheel 45* towards the golfer. (VSP is 45*).
You can see that for every degree the "carriage" is going down, it is also going 1 degree to the right (outward) as well.
And after the ferris wheel bottoms out, it is going 1* left for every degree up.
Therefore if it is going 5* up, it is actually going 5* left of the so called Swing Direction (the direction at lowpoint).
Now you have a face and true path 5* left of the Swing Direction. Bam - straight shot at the target.
If you didn't get kicked off, you'de have to quit after it got dark and you hadn't finished the first hole
VSP 90*: the outward becomes increasingly insignificanter the steeper the VSP. Any Professor Professor Doctor Doctor of Mathematics out there could work out (with some difficulty) what kind of mathematical relationship exist between the left bias HSP with the steepness of the VSP together with the low point determined by shaft angle together with low point determined by other factors (eg lunging/dipping) together with face angle determined by shaft/lie angle together with face angle determined by other factors (eg twisting). The you would habe to factor in the angular speed of the club relative to the shoulders and the arms. No, I'm not seriously suggesting this can be worked out, I just want to make the point that maybe its not quite as simple as x* downwards = y* outwards and requires a thereof dependent resultant relationship between path and face every time with no exeptions.
Yes, steeper VSP's have lesser outward/inward biases.
There IS a relationship between the path variables:
True Path = HSP - AoA[tan(90-VSP)]
I haven't seen any suggestion that face is tied to path on an absolute basis.
True Path = HSP - AoA[tan(90-VSP)]
The whole concept is based on a determinable low point, to my understanding determined to be at the point where the shaft is (from a front on camera view) perpendicular to the ground. Therefore, because of the the other factors (mentioned in my previous post) influencing low point, I don't think that the equation is in practice truly correct.
For clarification, of course I understand the argument about down = out and the trigonometric relationship between HSP, VSP and the angle of the shaft. I am suggesting that there are other factors involved in the stark reality of a golf swing which can change this relationship, or at least result in a less accurate prediction of ball flight when using this equation to determine true path.
Brian Manzella
Administrator
Low point may or may not occur when the shaft is vertical to the ground.
What the heck is your point?
The D-Plane has FINALLY answered the UN-ANSWERED questions of the golf swing result—ball flight.
Sound like it must have disproved something you like.
S
SteveT
Guest
True, but you must also take into account the droop dynamics of the clubhead and shaft tip which alters the face angle at Impact. The inclined swing plane and club path is therefore not the only factor that affects the clubface normal vector.
For compact blade irons, the clubhead CoG is very nearly aligned to the shaft axis, therefore the clubhead droop will be in line with the shaft axis. However for clubs like the driver head with the CofG well behind the club face, the eccentricity will cause the driver head to close as it droops and twists.
These factors must be taken into account, because droop and twisting can substantially affect Impact results. Shaft stiffness, swing speed and downswing shaft loading profile are direct factors that affect the clubhead normal vector.
Yes, and the driver face closure is also due to CofG alignment and tip droop. The question is: where and how much is the face closing due to droop and twisting? Geometrically, a 5º upward strike is about 5 inches past the bottom of a large swing radius.
The True Temper ShaftLab provided data on how much the clubhead toe deflects up and down during the downswing shaft loading, but alas, ShaftLab is no longer available.
Again, a 4º downward strike would geometrically be about 4 inches before the bottom of the swing path and typical of wedge shots. Interestingly, a "fat" divot seems to track straight, but a divot after the ball seems to skew left, or the inside. I have suggested that this inside skewing is due to the clubhead losing it's droop and returning to a toe up position causing the heel to dig in first and torquing the toe around to pull the divot inside. The straight divot reflects the droop pulling the toe down and flattening the club sole level with the ground.
A scientific study of the Impact event also revealed there is a "kickback" effect between the ball and clubhead, whereby the clubhead "whipsnaps" during the 0.0005 ms Impact event. This kickback is timed in a microseconds which means it's very fast. It has the effect of 'slinging' the ball off the clubhead. Then there is the COR face "trampolining" effect!!!
I guess the question is how can a golfer take into account all the static geometric and dynamic factors to determine how the D-plane ball flight is affected?
Btw .. does anybody know why Jorgensen called it the "D"-plane ?
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One would have to agree with this. Doesn't necessarily make the D-plane laws wrong though as this can be factored into the measurement of True Path and Face by Trackbaby, if they are being measured and not extrapolated by using an equation.
Do the distances not depend on the combination of the various angular speeds (club, shoulders, arms)? On a lighter note, have you factored body weight into your calculations
Hey Steve, although I don't know you from Adam, my guess is if you don't know this then nobody does
Down plane?
Or maybe two straight lines joined by a curved one, the lines representing the true path and the clubface alignment and the curve representing the ball flight.
On the contrary, Brian. I'm as happy as you about the revelations of the D-Plane. At the beginning of your excellent video explaining the laws of D, you mention your one time frustration about hitting inexplicable hooks. I hated golf for many years because of that same shot - the hook that shouldn't have been a hook. NOONE could tell me why. And I mean NOT ONE SINGLE SOLITARY MAN, WOMAN OR CHILD! I asked enough guys (golf pros). One TGM guy got quite close when he suggested that my clubface must be closed at separation, but of course it wasn't - at least not to the HSP. I love D-plane with a passion, because I can finally hit it again like I did when I was a niaive young guy slamming balls at the flag based on feel and what works best. Only now I know why it works.
My point is this: that simple geometric equation working out degrees relative to a wheel analogy does not tell the whole story. Its an over simplification. "Keep it simple, but not simpler than it actually is".
Kevin Shields
Super Moderator
Because it was "D"escriptive of where the ball started.
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