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Hinge Action meets "The D-Plane"
Dr Theodore Jorgensen meets Mr Homer Kelley....hinge action and the D-plane
Are these 2 ideas compatible? |
OK, to expand a little more....
How did Homer and Dr. T explain (compare and contrast) : 1) Initial ball flight? 2) Curvature of ball flight? My understanding so far:- 1)Homer and Dr T (Mr T's more educated brother) both agree that initial ball direction is predominantly due to clubface at impact (Homer stated seperation and Dr T probably didn't care ...) 2)Homer thought that clubface behaviour during impact interval (hinge action) could influence ballflight in addition to the accepted method which uses disparity between clubface at impact and clubhead direction through impact - something that Dr T explained with his "D-plane". Hinge action users (I place myself in this group) can demo the different ballflight behaviour that we can create (and the ball don't lie)- is this really a different form of physics or are we just altering the D -plane alignments? Looking for discussion - thoughts - musings - but not too many hard line warriors with an axe to grind.... thanks. |
D-Plane For Dummies
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Please explain the 'D-Plane' (for the rest of us) and contrast it with TGM's Turned Shoulder Plane Angle (10-6-B) and On Plane Right Shoulder Turn (10-13-D). Your explanation, graphics and links will be appreciated. Thanks! :salut: |
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Here's a link to Jorgenson's book that goes into the D-plane . . . http://books.google.com/books?id=fpLWA4TygqwC&pg=PA87&lpg=PA87&dq=d-plane+jorgensen+golf&source=bl&ots=kxH9HM2z7m&sig= Q1ZQxVVVIzJ-R9CIKs2St4jB8nM&hl=en&ei=XWHlSaK3IuOLtgeI5YGvDA&sa =X&oi=book_result&ct=result&resnum=2 Basically this guy is saying that generally the ball's starting direction is 80% face and 20% path and represents that with a "ray" or "plane" coming off the face. The ball curves in relation to the path vector. It took a computer nerd to figure out that the face controls the starting direction which of course Mr. Kelley figured out in the summer of 69. But I think the one thing that is somewhat different that the computer geeks have posited is that the ball is on the club for such a short amount of time that impact and separation are in essence the same . . . there by making hinge action "obsolete". Therein lies the "controversy" of the people who want to rip Mr. Kelley's science. Here's some more potentially interesting stuff from "trackman" . . http://trackmangolf.com/newsletter/m...ngDistance.pdf |
Thanks Bucket
Havent had a chance to read all of that yet but.....How on earth could they think Separation to be immediate? That would render Compression a constant then wouldnt it? No Impact Interval, no Hinge Action , no Compression? I believe Hinge Action to be as old as golf itself. While Homer defined/decoded Hinge Action golfers such as Palmer and Nicklaus have touched on it in there writings in regard to chipping and pitching. Drewit or Yoda could probably add many other authors to a list..... I bet Old Tom Morris probably had an Angled Hinge cut shot.......or a low, running Horizontal bump and run shot. OB |
Here is an excerpt from James Braid's "Advanced Golf", published in 1920.
I dont know if this counts as an early description of Hinge Action or not but it sure reminds me of the Horizontal and Vertical Hinging. http://www.hickorygolfers.com/swings...raidmashie.htm |
Hinge Action
All you are really doing is figuring out a way to come into the ball with the clubface closed, square or open. You are not controlling that through the impact interval. Whether you have a full roll, half roll, or no roll feel again you are just figuring out a way to get to the ball with the face in a certain condition.
That being said I think hinge action is important to give people a balanced motion. As a player you can achieve certain shots with with the different feels of hinge actions. Even though you may not be actually changing the face through impact interval , the feels can help you get the clubface into different conditions coming into the ball. |
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Rhythm, assuming I understand you correctly, I believe you are discounting the effect of Layback during the Impact Interval. I can create very different ball behaviours with the clubface held perfectly square at impact on the shortest of chips. With a flat left wrist. Horizontal Hinge Action of the left wrist creating a closing only , no layback of the Clubface Motion. Vertical creating a layback of the clubface only motion. The clubface square to the Target Line at impact. Surely the ball must react to the laying back clubface during the Impact Interval. This is not unique to golf or G.O.L.F. a hockey player for instance knows how to "roof" a shot when in tight on a goalie with a laying back of the sticks loft, dynamically, while the puck is on the stick. Well maybe not the Ottawa Senators players but certainly most of em do. An intentional opening of the clubface at Fix and Impact is a Cut Shot procedure a totally different concept that may or may not be employed to increase the effective loft of the club and/or to expose more bounce in the sand. Here too the ball flies in a direction in accordance with the face angle .... to the right higher, shorter and with slice spin if opened up. Try this when in tight on a goalie with a gaping hole upstairs and watch it go wide right and expect a long rest on the end of the bench, or maybe even a trade to Ottawa. |
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There has to be some ultra high speed ball impact footage that can help determine how much the face angle changes. Although, from our POV, the hinge action that is applied during the capture would be an important variable. |
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PLEASE DO NOT EQUATE "D-PLANE" WITH ANY OTHER TGM QUALIFIED INSTRUCTORS WORK (see, not just Ben Hogan and Homer who can use caps for effect!). It is Dr. T's phrase as far as i am aware... For those who state that Hinge action is just altering the clubface at impact...hence d-plane alignments at impact... does anyone have proof that the clubface behaves differently PRE-IMPACT for horizontal hinge versus vertical hinge which we obviously feel as though they occur through impact?? ie. "the club is preparing pre-impact to get to a different destination post impact" ...as clubhead travel differs post impact for horizontal and vertical hinge actions. AGAIN, I stress keep this is meant to be a non-patronising / non-confrontational discussion...Thanks - keep your thoughts coming. |
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But I would say that BOTH Mr. K and Jerkingsome or whatever his name is both understand that the face controls the starting direction and the divergence of the path to the face makes the ball curve due to tilting of the axis it is spining on . . . and Mr. K didn't have no 'puter. Bottom line swing right of the face ball hooks . . . swing left of the face and it fades. There are some big pieces in this regards to shaft lean as well and how you get your hands on the club. You're cool with me and my post wasn't meant to make you into no criminal. |
I know Andy Plummer, co-originator of stack and tilt, (and a member of this forum) bases his assertion that face angle determines initial direction on high speed video. You never know, he may have studied this subject as well.
Maybe someone who knows him could pm him and ask him to post his views on the subject. |
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...in the UK we use "Deliverance" as a cultural training aid for tourists who fancy a trip to your parts! |
Or how about Top Gears run across the Southern States? It might have been Buckets gas station :golfcart: :laughing9
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I believe that Dr. Jorgensen's work would disagree that hinge action, whether horizontal, angled, or vertical, could have any effect on ballflight with regard to how the face is behaving during the "impact interval' (time the ball is in contact with the face of the club). I don't believe he would agree with the notion that the face is 3 degrees more open at impact than it is at seperation, either; impact doesn't last long enough and the face doesn't rotate fast enough for that to be possible. This is just from what I understand of his research.
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The line of compression being a straight line. |
Doesn't anybody read "Search For The Perfect Swing"? It showed that with good friction during collision, the ball will start in a direction which is 65% of the difference between the clubface angle and the clubhead path, favoring the clubface angle. Reduced friction moves the starting direction closer to the clubface angle. The book debuted in '68, way before "The Physics of Golf", and one year before Homer's. The research findings are all being confirmed present day by TrackMan. I don't think Homer was too pleased that a golf "science" book came out one year before his life's work. I don't beleive that many TGM devotees have studied "Search", but if you want a plethora of good science regarding the impact collision and much else, including biomechanics of the golf swing, then read "Search". It can only aid your understanding of TGM.
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I would like to see the results of an accomplished TGM pro (Brian Gay) work through the hinges while on Trackman. This has to have been done already by pros for equipment fitting changes, etc. Would be interesting to get feedback about what the pro thought the hinge did and what Trackman says the result is.
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Thats interesting, Max I'll have to try to get a copy, thanks. Did it talk about an impact interval then as opposed to it being instantaneous? When you say "65% of the difference between the clubface angle and the path"........are you suggesting that was similar to TGM's at right angles to the leading edge? Leading edge to me implies left to right not up and down. And how would that compare to modern thinking in terms of left to right ? Isnt Trackmans 85% an up and down variance? Not sure, but Id be interested in knowing. |
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As far as starting direction, it is 3 dimensional. You can't separate left and right from up and down. It is going to do both. IIRC the 85% number is a 2d representation of a 3d image. |
Nice OB. Very interesting!
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YBGF |
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K, thought Id read somewhere that the 85% was more the launch angle than the "left and right" in my sad terminology. What is "IIRC"? |
IIRC - "If I Remember Correctly"
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It's all in "Search". I'm still trying to figure out exactly what is in TGM. But I do know that this stuff is not. |
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Here's something that may help. It's important that you understand that the clubface can point at the target at separation or maximum compression or where ever you think the greatest moment of impact would be - and the ball can leave the clubface at right angles - AND the ball won't fly at the target!! Because it's riding on the clubhead. Think of another example - The train is moving down the tracks at 100MPH (clubhead) and you throw a ball off the train (clubface) at a right angle to the path of the train at 100MPH - you threw it at right angles to the track- did it fly at right angles to the track? NO, it flew at a 45 degree angle to the track even though it separated from the train at right angles to the track. There's more there - if you're interested but this creates a condition where on the small picture Homer Kelley's statement that the ball leaves the clubface at practically right angles to the clubface - The ball in relation to the clubface at right angles is dead on! While the ball movement in relation to the target would be flying in a straight line right of the target. The affect of the 65% or 70% or 85% clubface orientation of the ball flight in relation to the target - would be determined by the Vector quantity of the clubhead i.e. the train, based on clubhead speed, efficieny of compression, etc. - Let's say you are going to run over Bucket with your car and you have a slanted snow plow on the front - the more force you can create with the car, and the more he sticks to the blade and rides along with the blade before bouncing off - the more effect the car vector will have on his flight into the ditch. Does it leave the face at right angles - YES. Does the clubface influence the flight say 70% versus 30% for the clubhead - YES It's not either or. You just need to identify the context in which you are discussing the subject matter at hand. |
I have not read In Search of in years. It is basic reading for anyone doing the GCA clubmakers course. A good read, lots of good stuff but plenty of missing bits too.
Launch angles never took into account how far forward hands vs clubface were, which explains a heap of the difference between a clubs vertical measurement and actual launch. InSearch never even considered right arm thrust, so was purely swinging in theory. Having started with InSof, and then being taught TGM, there were paradigms to overcome in my mind. TGM just blew it away, adding to and exchanging some bits. Most studies just miss the 'glance or crush' impact-separation area. Time is relative but far from irrelevant. In Gummers book, was it not TJ who Homer had his book ticked off by? Good to see Clubface is now seen as of a much higher order than Path by most out there now. |
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Im fascinated by this stuff, thanks. |
Wow. I wrote this, then realized, it's a long and vapid post. Sorry for the inconvenience. All of the following Jorgensen quotes are from chapter 9 of his book.
I think that people who explain Jorgensens "D Plane" stretch it a bit too much. Quote:
So somewhere along the line, the clubface becomes square to the path of the clubhead. Does Jorgensen say where along the path the Clubface becomes square? No, but we can assume somewhere around Impact. Does he tell us "How" the Clubface became Square to the Path? No, but who's asking anyway. Jorgensen is only stating 2-D-0: Quote:
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It's not that the "D Plane" is anti-TGM, it's that Jorgensen did not consider Hinge Action. Jorgensens "D Plane" is based on "Glancing Blow" Theory. Glancing Blow theory is great for Ping Pong and Tennis Balls but the Golf Ball has a "Solid-ish" core. "Compression" theory is applicable to explain the spin cause by the collision between a Golf Ball and Club. The Two Theories are very different. The following example can highlight their difference. Jorgensen said: Quote:
Consider test results when Clubface surfaces are altered. A clubface without grooves can produce nearly the same amount of spin from one with Grooves when hit from a dry and tight lie. A study I recently read, compared 3 surfaces, Smooth, roughed and grooved and under 3 different conditions, dry, oiled and oiled wiped-off. The results were not supportive of the Glancing Blow theory. In fact, there's hardly any mentionable difference in spin rates. I think the "D Plane" is an acceptable way to explain Ball Flight for anyone that swings the Club and can hold the clubface square to the clubhead path during Impact. I also think that "Trackman" can improve by using Low-Point of the Sweet-spot Orbit to calculate the Horizontal Swing Plane rather than the Ball Location. But their interest is explaining "How" the ball tracked, not "Why". "How" and "Why" is like "night" and "day". |
Well thought Daryl. The two frameworks seem somewhat differnt to me, but not mutually exclusive. I think the biggest difference is that TGM is more clear about what happens during the impact interval (hinge action) while Joergensen's D-plane is a more explicit and systematic and perhaps more accurate description of what TGM says about D-plane-ish character of the ball flight.
Not quite sure about this though: Quote:
I have a driver that is cryo treated or something. Very hard surface that I can still use as a mirror after 5+ years of use. It's by far the best driver I've ever used. But I can't use it in rainy weather. If both the ball and the club face isn't dry I get very little back spin, only 50-60% of normal carry and a sometimes a weird ball flight. This must be due to hydro planing or some other mechanical condition that reduces the friction significantly. I'm thinking the former. But this shouldn't affect the quality of compression as far as I can see. And it doesn't feel like it does so either. I am guessing a glancing impact with good ball compression here. But that's only a guess. |
I have spent some time studying D-Plane, I'm sure it's good stuff, but it just made my brain hurt. I'm not wired that way.
What's wrong with: 2-D-0 DIRECTIONAL FACTORS The direction of the ball will always be practically at right angles to the Clubface and square to the leading edge of the Clubface at separation HOMER KELLEY Thats good enough for me. John Dunigan does a really good job of describing it the same way, very simply. http://www.youtube.com/watch?v=C_uYCaV6DNI "Take my word for it." I Love it! Kevin |
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Daryl, your approach to TGM is rubbing off on me. The big difference is I need a lot more help in getting it. I appreciate your insight and assistance!
Kevin |
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When the Ball and Clubface are wet, the force of Impact transfers the water from the ball to the face of the driver. The Driver face was almost dry by the time it struck the ball. As impact occurs, water is forced away from the impact point and compresses at the impact perimeter. As the Driver Face moves through the Ball location it's provided with a steady spray of water (at 100 MPH). This interrupts the flow of water away from the impact point perimeter. Water at the Top of the Impact perimeter will escape upwards because of the Sloped Driver face(but not fast enough). But water at the bottom of the Impact perimeter will also escape upwards, into the Impact point. Keep in mind that you're creating as much compressive force on the water as you are on the ball but water flows easier than a solid. As the ball begins to separate from the clubface, the clubface hold on the ball is at its weakest and the water pressure is at its greatest. It's that moment, I imagine, that the slide occurs. So even though it may feel like a solid shot because you feel the heaviness of Impact, compression was lost when the clubface/ball contact was most vulnerable. Dry the Ball before placing it on the tee and the bottom of the ball may stay dry enough. Grooves on the Clubface help relieve the water pressure but only to a point, until they're filled. As the Driver face slides down the ball, farther from ball center, compression is relieved at the initial compression point and the ball will travel less distance. It will also have a higher launch angle. Reduced Backspin will cause the ball to wobble in flight. One drop of water is more than enough to wet the entire contact surface between the ball and clubface. But to get that driver face to slide, we're talking about a lot of water. At least 5,6,7,8,9 drops. ------------- The D Plane may be able to add additional material for TGM but not to the science regarding collision. Only what happens afterward. |
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Homer didnt agree. Though he wasnt the first to propose that the opposite was actually true, his views on the subject were still considered to be "different". Even the tape recordings of his GSEM sessions contain some lengthy discussions on this subject. So, its my opinion that in Homer's day 1-L 16 and 17 were somewhat controversial (ish) pronouncements. There's the context. Today, where we have an argument over whether Homer was correct vis a vis Trackman etc it should be remembered that the fight in his day had him on the compete opposite side of the geometry. A fight he won. So dont take "square to the leading edge too lightly" although its wasnt anything like the "Frankly Scarlet , I dont give a damn" of its day, golfwise it was "different". That more than Trajectory was where the controversy lay. And now for the rest of the story..... The word "practically". You could take that to mean "almost" or you could take that to mean "for practical purposes". I believe Homer meant the latter. The book he once said was "written for the guy standing on the tee". So I believe he meant something like.. "for practical purposes", the player should align the clubface as if the ball will leave vertical to the face and square to the leading edge. Did Homer actually think that the ball responded that way literally, every time? No. Although again, I believe he thought the variance was far more pronounced in terms of Trajectory than in terms of Direction (left and right from a birds eye perspective). 2-B TRAJECTORY CONTROL: Quote:
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Does this mean Homer is at odds with Trackman etc? I dont know. I dont care really. Its an argument about how correct Homer was given the theoretical fight he was in during his day. I'd be interested in seeing how Trackmans 15% is divided amongst what Homer termed Direction and Trajectory. Which one has more associated variance? I bet its Trajectory. Is that where most of the 15% lies? Anyone know? |
Honestly, I was surprised at everyone's reaction to D-Plane awhile back.
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I am not an engineer but the beauty of a detail is not lost on me, either, esp. since my Financial Planning days when I learned that the "Law of 72" means that when interest is paid on an investment or bank account, money "almost doubles" when time and interest multiplies to produce 72 (9 years @ 8%). That's interesting, right? Useful, too! But there are a lot of if's in there, like the D-Plane. I saw John's video and John seems pretty level-headed. I see the value of knowing where the ball will go and how it'll get there. I really do. My caveat is that the situation is similar to me beating balls on a range, even a dirt range. Supposing certain things happen at impact is supposing a lot. My home course is really flat whereas my local courses are very hilly. Whatever distances I get at the range are simply conversation starters for my local courses. The D-Plane is just that for me, a conversation starter. Thank God for engineers of all sorts. When a detail taunts them, they smile and say "just wait!" When a 4th-grader taunts me, I smile too, much like Godzilla dreaming of downtown Tokyo! Our challenges inspire us and define us! Can't wait until April! :golfcart: ICT |
I think the D-plane was a conversation starter for Homer as well. But I guess no one was interested in that conversation when the book was written so he didn't develop it any further than he did.
Chapter 2 certainly has all the fundamentals in place for deducting the d-plane from theory. It all starts with the line of compression not being identical to the face angle of the club... |
I find this interesting....
I think that all here has heard of that Gary Wiren, as the Director of Education, Learning and Research for PGA in the past, sent the book to MIT and to the University of Nebraska for a test.
The feedback was that the science was basically sound. The interesting thing is that one of the scientists that examined the book was.......... Theodore Jorgensen who btw was involved in the manhattan project in his early days. |
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