What cue stroke are you using?
- Thread starter ENGLISH!
- Start date
Layman's Bio-mechanical explanation
While I do not have a degree in mechanical engineering, I would like to take a stab at an explanation of how a pendulum stroke can have the tip of the cue traveling straight for several inches.
First I measured from my elbow to where the cue would be in my fingers. It was 15". So I scribed an arc with a radius of 15". I then took a straight line 5" long and laid it so each end terminated on the arc. This gave me a gap of 3/16" between the center of 5" line and the arc. I then measured from my stroke hand with my forearm plumb (I try to set up so that my forearm is plumb at the moment of impact with the cue ball.) to my bridge hand and get 40". I then measure from my bridge to the cue ball, that = 8". If I remember my basic rules of leverage a movement 3/16" at my shooting hand would translate to (8/40) X (3/16) = 3/80 or.0375" with 1/16=.0625. That means without any adjustment with the wrist or fingers the tip will vary 1/32" over 5".
I am of the "That's good enough for the girls I go with" school of measurement. So I would call that straight.
However if you will settle for nothing less than perfection....It would be possible to have the cue tip go perfectly straight by simply squeezing the cue at the appropriate time. Holding my cue and tightening and loosening my grip easily gives 1/4" change in elevation.
The wrist is another hinge point that could easily take up that 3/16" variation over 5" of stroke.
So I conclude my laymans explanation of how a pendulum stroke could cause the cue tip to go straight for several inches.
While I do not have a degree in mechanical engineering, I would like to take a stab at an explanation of how a pendulum stroke can have the tip of the cue traveling straight for several inches.
First I measured from my elbow to where the cue would be in my fingers. It was 15". So I scribed an arc with a radius of 15". I then took a straight line 5" long and laid it so each end terminated on the arc. This gave me a gap of 3/16" between the center of 5" line and the arc. I then measured from my stroke hand with my forearm plumb (I try to set up so that my forearm is plumb at the moment of impact with the cue ball.) to my bridge hand and get 40". I then measure from my bridge to the cue ball, that = 8". If I remember my basic rules of leverage a movement 3/16" at my shooting hand would translate to (8/40) X (3/16) = 3/80 or.0375" with 1/16=.0625. That means without any adjustment with the wrist or fingers the tip will vary 1/32" over 5".
I am of the "That's good enough for the girls I go with" school of measurement. So I would call that straight.
However if you will settle for nothing less than perfection....It would be possible to have the cue tip go perfectly straight by simply squeezing the cue at the appropriate time. Holding my cue and tightening and loosening my grip easily gives 1/4" change in elevation.
The wrist is another hinge point that could easily take up that 3/16" variation over 5" of stroke.
So I conclude my laymans explanation of how a pendulum stroke could cause the cue tip to go straight for several inches.
What part debating do you not understand? That's exactly how it works. If there's something that supports my argument (which there is),and nothing that supports yours (which there is not). Who do you think has the better argument?
And for the last time
IN BOTH THE PISTON AND THE PENDULUM STROKE, CONTACT OCCURS WHEN THE CUE IS STRAIGHT AND AS LEVEL AS POSSIBLE. THE ONLY DIFFERENCE IS WHAT HAPPENS WITH THE CUE (ARC VS. STRAIGHT THROUGH) AFTER CONTACT, BUT THAT (ACCORDING TO FACTS AND VIDEO EVIDENCE) HAS NO EFFECT ON THE CB.
Go back & read the JA apologizes to MD thread & tell me why I should do anything for you.
AND when I mistook you for Ray Martin & asked for a clarification, as far as I know & I checked, you did nothing to make me aware that you are not Ray Martin as someone else has advised me.
That certainly leads me to believe that you are not opposed to deception & are not one to be trusted.
That also makes me doubt your sincerity here. It seems to me that you might merely be someone's puppet & doing their 'dirty' work.
Why all of sudden are you interested in this topic only after the JA/MD thread interaction?
Sorry. I have too many questions about you to give you any answers.
Apparently there is more deception on AZB than I would have ever thought.
You accuse people (myself included) of only quoting certain parts of your post(s), and then here you are, changing the subject, when presented with evidence of what you've been looking for.
Watch Neil's videos. Seriously.
While I do not have a degree in mechanical engineering, I would like to take a stab at an explanation of how a pendulum stroke can have the tip of the cue traveling straight for several inches.
First I measured from my elbow to where the cue would be in my fingers. It was 15". So I scribed an arc with a radius of 15". I then took a straight line 5" long and laid it so each end terminated on the arc. If I understand you correctly, I would believe that would be an error. The line should be at the bottom of the arc with an equal distance on both sides. Why are you putting the end points on the arc line which raises the center of that line higher than the bottom of the arc? This gave me a gap of 3/16" between the center of 5" line and the arc. I then measured from my stroke hand with my forearm plumb (I try to set up so that my forearm is plumb at the moment of impact with the cue ball.) to my bridge hand and get 40". I then measure from my bridge to the cue ball, that = 8". If I remember my basic rules of leverage a movement 3/16" at my shooting hand would translate to (8/40) X (3/16) = 3/80 or.0375" with 1/16=.0625. That means without any adjustment with the wrist or fingers the tip will vary 1/32" over 5".
I am of the "That's good enough for the girls I go with" school of measurement. So I would call that straight.
However if you will settle for nothing less than perfection....It would be possible to have the cue tip go perfectly straight by simply squeezing the cue at the appropriate time. Holding my cue and tightening and loosening my grip easily gives 1/4" change in elevation.
The wrist is another hinge point that could easily take up that 3/16" variation over 5" of stroke.
So I conclude my laymans explanation of how a pendulum stroke could cause the cue tip to go straight for several inches.
First I'd like to thank you for your attempt.
Wow. I was looking for a simple bio-mechanical explanation, I had not envisioned so many numbers. I was looking for a simple do or doing this cause(s) this type answer. Before we go on please see the blue in my quote of your post & explain why you did that as opposed to my option. If we can not agree on step one we have no basis from which to proceed.
Thanks in advance for the clarification.
Rick
Last edited:
Pidge,
Four things. Well technically more.
1. This thread was not intended as a platform for any debate.
2. There are much more than 2 parties involved.
3. The topic from the closed thread in the Ask the Instructor sub forum was 'can anyone give a bio-mechanical explanation of how a straight/'level' tip movement for several inches is possible in a fixed elbow pendulum stroke as was asserted by randyG in another thread?'
4. I find it interesting that the thread was closed after I bumped it when it went over 6,000 views. It got about 600 more in just a few days after I bumped it. It's now over 7,000. It's also interesting, to me, that Sean, Neil, & Tony have brought the debate here. Yet I am supposed to be the one obsessed.
I hope this give you a better understanding.
Best to Y'a,
Rick
I've watched Neils videos, and thanks for the repost because I missed the original post.
Its not so easy to see but if you pay close attention its visable, and also the outcome of the CB shows what really went on.
On his piston video the CB slides forward a few inches when he was setting up for a CCB hit. The tip has clearly risen, maybe due to him not being comfortable with the style of stroke. On both the other strokes the CB just stuns.
I'd like to see a close up side on shot of just the bridge hand to the CB. Slow motion would give us with not so good eyes a chance to see what's happening. I'd also like to see a close up front view of the stroke without a CB or cueing over a CB.
I've tried all the strokes in this thread for shits and giggles and all can be done with a level cue and a straight cue for the last atleast 4 inches of the stroke before contact and the same again after contact (I did them without a CB but lined up against a doughnut as the CB). My wrist action changed with each stroke to keep the cue as level as I could for as long as I could.
So one has to ask who gives a crap if your cue rises or drops before and after contact?
Its not so easy to see but if you pay close attention its visable, and also the outcome of the CB shows what really went on.
On his piston video the CB slides forward a few inches when he was setting up for a CCB hit. The tip has clearly risen, maybe due to him not being comfortable with the style of stroke. On both the other strokes the CB just stuns.
I'd like to see a close up side on shot of just the bridge hand to the CB. Slow motion would give us with not so good eyes a chance to see what's happening. I'd also like to see a close up front view of the stroke without a CB or cueing over a CB.
I've tried all the strokes in this thread for shits and giggles and all can be done with a level cue and a straight cue for the last atleast 4 inches of the stroke before contact and the same again after contact (I did them without a CB but lined up against a doughnut as the CB). My wrist action changed with each stroke to keep the cue as level as I could for as long as I could.
So one has to ask who gives a crap if your cue rises or drops before and after contact?
Please read post #138.
Thanks. Quite the ingenious post.
Two things first.
1. Please show me any evidence that shows that a different path of the tip DURING contact with the ball has NO DIFFERENT EFFECT. Difference Begets Difference.
2. How many years in human history passed before it was discovered & proven that the planet that we live on is 'round' & not flat & that the planet Earth revolves around the Sun & that the Universe does not revolve around 'Us'? How many? Or...how much time passed before any other discovery was made to disprove the past.
I'm not saying that there is any new discovery here.
But If there is a difference then it begets another difference. No matter how 'large' or small that difference is, it is a difference.
Ask yourself... why did randyG even make the assertion regarding the straight line tip travel if it is irrelevant. To me, he certainly seemed to be making it to look like a benefit & I would agree. That is why I asked for an explanation. Bob Jewitt's charting indicates 3 arcs with only a near instantaneous transfer from one to the other for a fixed elbow stroke while indicate straight tip travel for an elbow dropping stroke.
If you only want to regurgitate what you have been told & do not want to think for yourself, then don't.
Like CJ has said, those that have 'realeyes' will see 'it' & those that don't will not.
Tennis ball moving 'level'...tennis racket with face perpendicular to flight is swung with the center of the face level with the path of the ball and makes contact with the ball at the center ter of the racket face & proceeds on that level line DURING contact till the ball leaves the racket.
Same as above but tennis racket starts out at a lower level than the flight level of the ball & moves up to the level of the flight of the ball at contact & proceeds to move upward DURING contact until the ball leaves the face of the racket.
The ball is hit at the EXACT same point on the ball & by the & the EXACT same point on the racket face with the racket in the EXACT same orientation & configuration AT contact. Everything in a freeze frame AT contact of each would be EXACTLY the same. No one could tell ANY difference because ther is no difference AT contact. The only difference is how both rackets got to that EXACT same position & then the path DURING contact is different & then the finish of the racket stroke is different. The finish AFTER contact effects the ball in NO way... BUT it is an indicator of what happened BOTH BEFORE & DURING contact.
So I will ask you another question that you will probably not answer & if not I am COMPLETELY & TOTALLY finished with you.
Does the tennis ball react EXACTLY the same in both of those scenarios with the contact point & position of the racket being EXACTLY the same?
YES or NO? Please? YES or NO, before anything else.
I don't know why I am being so specific. You never answered any of my other questions to you except when you thought it might be in your own best interest to do so.
Here is the blue....
I did it my way because it gives the same result but with only one measurement required. Since this demonstration was of my own invention, your option was not on the table at the time.
When you put a 5"long tangent line centered at the bottom of a 15" arc, what result do you get?
Pidge,
Can you tell me what you did to get 8" of straight/'level' tip travel for a complete fixed elbow pendulum stroke with no elbow drop? And did you do it with the cue sitting in a cradle grip?
I can do a wrist action alone (no arm movement) with the cue 'pinched' between the 2 points of my thumb & index & get about 8" of tip travel utilizing just the wrist where the tip moves fairly straight going back but it dives down on the front end. Now that is with the wrist cocking toward the elbow going back & toward the shoulder going forward.
I agree with your last statement except for a couple of things.
1. You left out DURING contact.
2. The finish can be an indicator of what happened both before & during contact just as how the cue ball reacts is an indicator of how & where it was hit.
Can you do me a favor? Can you explain why, for the fixed elbow pendulum stroke, Bob Jewitt's charting for the tip travel shows 3 distinct arcs with nearly instantaneous direction changes like a true pendulum actually does.
Can you explain why randyG made the assertion of straight line tip travel & it certainly seemed to me that he was making that out to be advantages.
Best to Y'a,
Rick
Last edited:
Another wonderfully ironic post.
Concerning that post you quoted -- oh my gawd. :thud:
Don't know where to begin with that one, but suffice to say his tennis ball analogy is not only full of holes, but completely invalid and inapproriate to use. Yeah, let's compare two SOFT surfaces contacting each other (the tennis ball and the racquet) -- which has a HUGE contact time because of compression and flexion of both surfaces -- to a situation where you have an absolutely hard surface (cue ball) and a semi-hard material with a hard backing that's too thin (the leather tip, that is) for any variability in contact time to mean anything. And, also let's completely forget about the fact that this supposed "difference in angle" he's talking about between a piston stroke's straight follow-through the cue ball vs. a pendulum stroke's slight dive after contact with the cue ball isn't even measurable enough to make a difference. "Oh my gosh! That 1/16 of an inch difference in attack angle is *SO* tantamount to my argument, and you numbskulls aren't seeing it!!" Yeah, let's forget the fact that the contact patch on the cue ball where the tip hits can completely consume that 1/16-inch difference.
Hit absolutely center ball on the cue ball with a piston stroke, and you get a stop shot. Hit the same spot on the cue ball with a pendulum stroke where the cue travel has started on its downward dip due to the pendulum arc (which you and I and everyone else knows this situation is ACTUALLY due to a bad "Set" alignment to begin with), and what do you get? The same stop shot! Good grief, some examples of the human species can get really brain-spinlocked on such minutiae that mean -- in the REAL world -- absolutely nothing.
I mean, I think we know what ENGLISH! is trying to get at -- he wants a stroke where he's "guaranteed" not to be affected by any rise and fall of the cue tip due to a pendulum arc. We totally get what he's getting at. But what he's completely forgetting -- as evidenced by the fact that he never took this to the table, nor took any instruction and instead relying on his own pure conjecture and supposition -- is that this is not what's happening.
What I find particularly hilarious is his comparison to the days where people believed the earth was flat and here he is trying to say the earth is round. What he's not getting is we are well past those days of supposition and have PROOF that a pendulum stroke gives more than a couple full inches of completely flat cue travel through the cue ball. But he's here arguing with us that the earth is flat -- based purely on his supposition and conjecture about what he "thinks" -- when it's LONG been proven the earth is round. He just refuses to see the proof. Forget the fact there is video evidence out there (including in this very thread); "my gosh, a pendulum arc just *HAS* to cause a perfectly-rising and -falling tip that has no straight travel to it whatsoever!" :thud:
He won't see this post, obviously, because he has me on his publicly-displayed Ignore list. Or will he?
Sad to see someone get *so* brain-spinlocked on such minutiae, then claim he's not the one continually bringing it up. (Umm... how about this very thread's existence to begin with? And all those he posted in the Ask the Instructor forum? And he's blaming RandyG for all this?)
I know this -- in my retirement years, I would definitely have MUCH BETTER things to do with my time than waste it on a forum on such stupid minutiae.
-Sean
Last edited:
Ok so I'm not sure where to start but ill try my best to explain what I do.
For the 8 inches of straight line travel;
My wrist is arched RIGHT back in a sense that I'm trying to make my little finger closer to my wrist and forearm. This is on the back swing. Upon contact my wrist is in a neutral 'normal' position and then after contact my little finger and ring finger take over the grip and tighten whilst my middle, index and thumb relax off and the pressure on the V between thumb and index loosens and comes away from the cue and the cue is pushed into the fleshy pad below the little finger.
Now, that being said, not everyone can do this due to obvious anatomy differences. And I don't do this on every stroke. Mostly I will drop my elbow after contact but ill choose the wristy option when I need a lot of spin on a soft shot. But it is possible, atleast for me.
I've never given during contact any thought. The contact time is so minute that it would be impossible for me to hit centre CB at the start and slide the tip up enough for even half a CB rotation by the time the contact is done. So my concern is purely on a straight stroke for 'X' amount of distance without a CB.
I dismissed the finish position when using a CB due to cue deflection. Unless I hit exactly CCB the tip would either go up, if I hit high, or low if I hit low. Hence why I tried each stroke without a CB.
I'm not Bob or Randy so I can't explain why either of them have said what they've said.
Hopefully this sheds some light on why I posted what I posted
Ok so I'm not sure where to start but ill try my best to explain what I do.
For the 8 inches of straight line travel;
My wrist is arched RIGHT back in a sense that I'm trying to make my little finger closer to my wrist and forearm. This is on the back swing. Upon contact my wrist is in a neutral 'normal' position and then after contact my little finger and ring finger take over the grip and tighten whilst my middle, index and thumb relax off and the pressure on the V between thumb and index loosens and comes away from the cue and the cue is pushed into the fleshy pad below the little finger.
Now, that being said, not everyone can do this due to obvious anatomy differences. And I don't do this on every stroke. Mostly I will drop my elbow after contact but ill choose the wristy option when I need a lot of spin on a soft shot. But it is possible, atleast for me.
I've never given during contact any thought. The contact time is so minute that it would be impossible for me to hit centre CB at the start and slide the tip up enough for even half a CB rotation by the time the contact is done. So my concern is purely on a straight stroke for 'X' amount of distance without a CB.
I dismissed the finish position when using a CB due to cue deflection. Unless I hit exactly CCB the tip would either go up, if I hit high, or low if I hit low. Hence why I tried each stroke without a CB.
I'm not Bob or Randy so I can't explain why either of them have said what they've said.
Hopefully this sheds some light on why I posted what I posted
Pidge,
What you describe is what I do too. That is before TOI.
If you do not mind & just for the heck of it, try this. (But first can we agree that the wrist hung down from the perpendicular forearm hinging back & forth is 'like' a small pendulum?)
Place a mechanical bridge on the table & set the stick on it with the tip about 4" over the edge & your bridge hand about 8 or 9 inches from the tip. Now set up with your arm straight down perpendicular to the table. Now with your bridge hand just lift the cue until it just barely gets off of the mechanical bridge. Then take the cue back with just the wrist action & NO arm movement. Let me know what you observe.
Now remove the mechanical bridge. Set up with the arm perpendicular & slowly make the wrist movement back & then forward with NO arm movement. For me, every time I do this with a still arm & just the wrist movement the tip dives down on the front end. Now with the tip where it is, drop the elbow. Tell me what you observe.
I would really appreciate it if you do this & let me know what you observe & I thank you in advance.
Best to Y'a,
Rick
Well Rick, you proved me right once again. I was asked by several what you would do when presented with the evidence you ask for. I told them that you would ignore it like it wasn't even there. (I already knew, because you have done so many times in the past already) You accuse others of not being open-minded, of being deceitful, of ignoring the truth, yet, you have proven to be all that yourself. You also have stated that you were man enough to admit when you were wrong. Fail again. By continuing to ask the same questions you have been provided answers too, and ignoring them, you have proven yourself to be exactly what you accuse others of. Great job at proving beyond a shadow of a doubt what you are doing here. Hope you are proud of yourself.
I've tried both and in each instance the tip lowers on the way back slightly. On the way forward it starts to rise. And then on the the portion that would be after contact it lowers again. The movement of the tip was very small. As is the arc in a pendulum stroke. It goes along with what I thought and that is it counteracts any diversion from the horizontal plane that a pendulum stroke would cause. More than enough to let me keep my cue level for 8 inches and let me hit the CB on the vertical axis where I intend.