Measuring shaft deflection

[garczar]

Yes, I have looked at all of the science being applied to the LD explanation. I have seen the research, videos, discussions, etc. I'm well aware of the perception. I'm not saying a new tip with fresh chalk will deflect less, and I'm not saying tip end mass has nothing to do with the way the shaft deflects in relation to the CB deflection. What I am saying is that we are missing something, trying to do a math problem without all of the factors.

My point is very clear. Remove the chalk from ANY shaft, and wet the tip to reduce friction. Now play pool. What happens? The exact same deflection(s) that occur when the CB strikes an OB. I'm not being snarky, either. Nor am I flat earthing it. I 100% believe science, but only when the science is thorough. You cannot leave out factors & reach an accurate conclusion. Friction is obviously a major factor, and by the very nature of chalking it is variable. That's my position, for now. It's always been an interesting conversation that has never satisfied. The concrete has yet to cure, so there's still some soft spots. Compare & contrast the deflection properties of ANY shaft with chalk vs. no chalk, wet tip. Basically friction vs. no friction. It's a simple comparison. Do that, then explain again to me how all of the science your using to describe LD applies.

Have you ever owned/played with a LD shaft? Take a 13mm solid-maple shaft and say, a 12mm LD(Pred,OB,etc). Put on same tips and chalk up. Now, shoot the cue ball from center-table to the middle diamond on end rail using 1.5tips spin, medium hard. The LD shaft will come closer to the target every time. Its not the friction between the tip and the cueball that causes this its the difference in the endmass of the two shafts. There's a big difference between deflection and a pure miscue which is what you describe in the no-chalk scenario.

 

[qbilder]

Have you ever owned/played with a LD shaft? Take a 13mm solid-maple shaft and say, a 12mm LD(Pred,OB,etc). Put on same tips and chalk up. Now, shoot the cue ball from center-table to the middle diamond on end rail using 1.5tips spin, medium hard. The LD shaft will come closer to the target every time. Its not the friction between the tip and the cueball that causes this its the difference in the endmass of the two shafts. There's a big difference between deflection and a pure miscue which is what you describe in the no-chalk scenario.

I'm debating the application of physics. My position is simple. The same physics apply regardless of the subject object(s). By removing the friction, my point is made clear. The same exact reaction that occurs between CB & OB also happens between CB and cue tip. Only by introducing an abrasive, inducing friction, do you alter the dynamics of that reaction. Dismiss the reaction as a pure miscue if you must, but be honest with yourself and me by first defining miscue. I mean really break it down & understand the physics, what's happening at the moment of impact & what results. The science is the same. Altering the size(mass) of the cue ball will accordingly result in a difference of energy assumption/transfer. It will not alter the path of either object, only the speed at which they travel after impact.

Friction is a variable that cannot be ignored. Until it can be quantified, the other science doesn't matter. It's haphazard to apply science to half of the problem while ignoring or dismissing the other half. Until it's a complete explanation, i'm not biting. Faith is for religion, not science. Define a miscue. Compare & contrast it to balls colliding, applying the science of deflection to each scenario. Now introduce chalk & note how the dynamics completely change.

 

[DaveK]

https://www.huffingtonpost.com/peggy-nolan/happiness-tips_b_3473923.html

give it a rest........... play pool


Kim

:lol: Not everyone is an ostrich :wink:

Dave

 

[garczar]

I'm debating the application of physics. My position is simple. The same physics apply regardless of the subject object(s). By removing the friction, my point is made clear. The same exact reaction that occurs between CB & OB also happens between CB and cue tip. Only by introducing an abrasive, inducing friction, do you alter the dynamics of that reaction. Dismiss the reaction as a pure miscue if you must, but be honest with yourself and me by first defining miscue. I mean really break it down & understand the physics, what's happening at the moment of impact & what results. The science is the same. Altering the size(mass) of the cue ball will accordingly result in a difference of energy assumption/transfer. It will not alter the path of either object, only the speed at which they travel after impact.

Friction is a variable that cannot be ignored. Until it can be quantified, the other science doesn't matter. It's haphazard to apply science to half of the problem while ignoring or dismissing the other half. Until it's a complete explanation, i'm not biting. Faith is for religion, not science. Define a miscue. Compare & contrast it to balls colliding, applying the science of deflection to each scenario. Now introduce chalk & note how the dynamics completely change.

You're going WAY down some wormhole here. I'm just talking about the difference in two cue shafts. Take one off, put the other on. Shoot the same shot. The LD shaft hits closer(sometimes WAAY) closer than a solid shaft. When i compared a Schon shaft to a OB Classic+ the difference was almost 3 full inches. You still want to say that's due to friction? I've talked to OB, Tiger and Predator about their shafts and all three say their tests show less endmass is the key to less cueball squirt. Believe what you want. I'll believe my own eyes. I'm gone.

 

[JoeyA]

Dr. Dave's cue ball deflection test.

https://www.youtube.com/watch?v=nx4r0NSsxqo&t=11s



JoeyA

 

[qbilder]

You're going WAY down some wormhole here. I'm just talking about the difference in two cue shafts. Take one off, put the other on. Shoot the same shot. The LD shaft hits closer(sometimes WAAY) closer than a solid shaft. When i compared a Schon shaft to a OB Classic+ the difference was almost 3 full inches. You still want to say that's due to friction? I've talked to OB, Tiger and Predator about their shafts and all three say their tests show less endmass is the key to less cueball squirt. Believe what you want. I'll believe my own eyes. I'm gone.

Well I didn't mean to offend you, just tried provoking some thought. Having worked with Royce Brunell (since you mentioned OB) on projects and having discussed much of this to no end with him, I can promise you LD has zero to do with solid shafts vs. hollowed out stuff. In fact, the project we were discussing before he died was an OB solid shaft with melamine ferrule. The last conversation I had with him was about 3hrs long where he had figured out how to do it, how to mass produce it, and was ready to invest in 10,000 shaft blanks to get it started. Not only have I hit with a low deflection shaft, I have been involved in developing them. While I am certainly no expert at any level, I am no layman, either.

My position in this thread isn't to discourage anybody from using LD shafts, or to dispute their legitimacy. There's more to the story than tip end mass alone, and the rest of that story has yet to be defined or quantified. Is it such a wormhole to want to find it out?

 

[dr_dave]

Is there any independent 'lab' anywhere that actually measures/compares shaft deflection (or is it squirt?) from different makers?

... not that I know of, but several shaft-testing "robots" have been built over the years. See:

robotic squirt-testing machines

There is also a fairly large collection of published data for a wide range of cues here:

published shaft CB deflection data

But fancy equipment is not required to get accurate and consistent results. CB deflection can be measured to compare shafts using a procedure such as:

NV D.15 - Cue and Tip Testing for Cue Ball Deflection (Squirt)

And shaft natural pivot lengths can also be easily measured using procedures described here:

cue natural pivot length

In fact, sometimes robotic testing machines can yield very misleading results. For more info, see:

Rules of Squirt Robot Testing

Enjoy,
Dave

 

[garczar]

Well I didn't mean to offend you, just tried provoking some thought. Having worked with Royce Brunell (since you mentioned OB) on projects and having discussed much of this to no end with him, I can promise you LD has zero to do with solid shafts vs. hollowed out stuff. In fact, the project we were discussing before he died was an OB solid shaft with melamine ferrule. The last conversation I had with him was about 3hrs long where he had figured out how to do it, how to mass produce it, and was ready to invest in 10,000 shaft blanks to get it started. Not only have I hit with a low deflection shaft, I have been involved in developing them. While I am certainly no expert at any level, I am no layman, either.

My position in this thread isn't to discourage anybody from using LD shafts, or to dispute their legitimacy. There's more to the story than tip end mass alone, and the rest of that story has yet to be defined or quantified. Is it such a wormhole to want to find it out?

I never said "hollow" once, just less tip-end mass. I've got a solid shaft with a Tomahawk ferrule(VERY light stuff) that is "lower" deflection than my other shaft but not as low as my OB Classic+. Meucci went the same direction with the Pro shaft. Its not hollow either.

 

[Jaden]

This is so true...

The issue with just having deflection numbers is that there is no way to take that and translate it into you playing better with a shaft. Your stroke may want a certain performance from the shaft to match how you hit the cueball without spending time to re-train how you play.

I think the only way you can find a shaft/cue is by trying a lot of them.

I have seen some players that have no idea why they are missing shots, and when I talk to them it turns out they are using an LD shaft because someone told them they should but don't know how to aim with one or using a non-LD shaft but don't know how to adjust for spin. It's not even their shooting flaws that cause the miss, they just don't know how to play with the equipment they have.

There's a reason that the old school standards We're for 10 to 12 inches for bridge placement and that is that it is the natural pivot point for standard shafts.

Ideally you want a shaft that has a pivot point where your most comfortable bridge position is. This is whether you do or don't use bHe.

That is because bridging at the cue's pivot point will correct for slight stroke deviations.

Jaden

 

[Cornerman]

My position in this thread isn't to discourage anybody from using LD shafts, or to dispute their legitimacy. There's more to the story than tip end mass alone, and the rest of that story has yet to be defined or quantified. Is it such a wormhole to want to find it out?

I gave my mechanical engineering view to Royce for a quite a bit 10-15 years ago on why the term "tip end mass" isn't really accurate for the collision dynamics . I've also explained it on these boards a half dozen times, but it normally gets dismissed apparently by all these wonderful people who don't know a thing about collisions. But, in the future, when everyone suddenly understands why "tip end mass" isn't the right term, everyone else will take credit, and they'll all educate me (us) about it.

So, I don't talk about it anymore. Fuggit.


Freddie <~~~ ain't talking no more, and off to the bar with my ball

 

[garczar]

I gave my mechanical engineering view to Royce for a quite a bit 10-15 years ago on why the term "tip end mass" isn't really accurate for the collision dynamics . I've also explained it on these boards a half dozen times, but it normally gets dismissed apparently by all these wonderful people who don't know a thing about collisions. But, in the future, when everyone suddenly understands why "tip end mass" isn't the right term, everyone else will take credit, and they'll all educate me (us) about it.

So, I don't talk about it anymore. Fuggit.


Freddie <~~~ ain't talking no more, and off to the bar with my ball

Who pee'd in your Wheaties? I'm just going by what at least three LD shaft makers have told me. Whatever the reason, its obvious after about five shots that when using side-spin an LD shaft will keep the cueball closer to your target line. If you've made post on why they really do/don't work send me link and i'll gladly read it.

 

[dr_dave]

I gave my mechanical engineering view to Royce for a quite a bit 10-15 years ago on why the term "tip end mass" isn't really accurate for the collision dynamics .

Freddie,

By “tip end mass,” do you mean the same thing as shaft endmass?

For those interested, the what causes squirt resource pages covers this topic in detail.

Enjoy,
Dave

 

[garczar]

I'm debating the application of physics. My position is simple. The same physics apply regardless of the subject object(s). By removing the friction, my point is made clear. The same exact reaction that occurs between CB & OB also happens between CB and cue tip. Only by introducing an abrasive, inducing friction, do you alter the dynamics of that reaction. Dismiss the reaction as a pure miscue if you must, but be honest with yourself and me by first defining miscue. I mean really break it down & understand the physics, what's happening at the moment of impact & what results. The science is the same. Altering the size(mass) of the cue ball will accordingly result in a difference of energy assumption/transfer. It will not alter the path of either object, only the speed at which they travel after impact.

Friction is a variable that cannot be ignored. Until it can be quantified, the other science doesn't matter. It's haphazard to apply science to half of the problem while ignoring or dismissing the other half. Until it's a complete explanation, i'm not biting. Faith is for religion, not science. Define a miscue. Compare & contrast it to balls colliding, applying the science of deflection to each scenario. Now introduce chalk & note how the dynamics completely change.

Post #2:http://forums.azbilliards.com/showthread.php?359199&p=4678437#post4678437 Looks like we're kinda on same page. That is you, right?

 

[Hits 'em Hard]

You're going WAY down some wormhole here. I'm just talking about the difference in two cue shafts. Take one off, put the other on. Shoot the same shot. The LD shaft hits closer(sometimes WAAY) closer than a solid shaft. When i compared a Schon shaft to a OB Classic+ the difference was almost 3 full inches. You still want to say that's due to friction? I've talked to OB, Tiger and Predator about their shafts and all three say their tests show less endmass is the key to less cueball squirt. Believe what you want. I'll believe my own eyes. I'm gone.

If you want to believe your own eyes, then provide a more concrete basis for your position. I own two OB+shafts, both sit in a case and will continue to sit in a case for quite some time. When measuring cue ball squirt, there’s more data to be processed than just the margins of deflections. When I did my testing my solid maple shaft had maybe, maybe a 1/4” difference in cue ball contact point. That was the max with the details to follow. The real data point is how far the cue ball is traveling. Using the OB+ shafts I found that 4 rails on a 9’ table is a good distance to shoot for to get an idea of consistent speed. My solid maple shaft had a definite difference on how far the cue ball traveled though. I was consistently at least half a table longer with my solid shaft that the OB+’s.

Now when I hit as hard as I could there was that considerable margin of difference most people see. Yes my solid maple shaft did gain some deflection, as did the OB+’s. But that this point the distance the cue ball traveled after was massive. Remember the whole point of deflection testing is using maximum spin. The OB+ shafts were considerably shorter on cue ball travel. I’d barely get the cue ball to hit the 6th rail with those LD shafts. With my solid maple shaft I was getting the 7th and 8th rail.

When I augmented my speed with the solid maple shaft to achieve the same deflection point that the OB+’s achieved, the cue ball travel distance became nearly the same. So the reality of the conversation is that there are about 5-6 data points I feel are important to conversation about LD shafts, yet no one ever gets past point 1.

And before it comes up, yes I was able to get my LD shafts to squirt the cue ball just as much as my non-LD shaft. It was inconsistent on distance traveled and path off the end rail. Hit the side pocket too many times.


As far as your “at least three LD shaft makers have told me” line, you’re gullible as hell then. It’s called sales marketing. Figuring out what terms can be said without people questioning the statement. But since you can’t figure out that speed plays a role in deflection, a LD shaft is for you.

 

[garczar]

If you want to believe your own eyes, then provide a more concrete basis for your position. I own two OB+shafts, both sit in a case and will continue to sit in a case for quite some time. When measuring cue ball squirt, there’s more data to be processed than just the margins of deflections. When I did my testing my solid maple shaft had maybe, maybe a 1/4” difference in cue ball contact point. That was the max with the details to follow. The real data point is how far the cue ball is traveling. Using the OB+ shafts I found that 4 rails on a 9’ table is a good distance to shoot for to get an idea of consistent speed. My solid maple shaft had a definite difference on how far the cue ball traveled though. I was consistently at least half a table longer with my solid shaft that the OB+’s.

Now when I hit as hard as I could there was that considerable margin of difference most people see. Yes my solid maple shaft did gain some deflection, as did the OB+’s. But that this point the distance the cue ball traveled after was massive. Remember the whole point of deflection testing is using maximum spin. The OB+ shafts were considerably shorter on cue ball travel. I’d barely get the cue ball to hit the 6th rail with those LD shafts. With my solid maple shaft I was getting the 7th and 8th rail.

When I augmented my speed with the solid maple shaft to achieve the same deflection point that the OB+’s achieved, the cue ball travel distance became nearly the same. So the reality of the conversation is that there are about 5-6 data points I feel are important to conversation about LD shafts, yet no one ever gets past point 1.

And before it comes up, yes I was able to get my LD shafts to squirt the cue ball just as much as my non-LD shaft. It was inconsistent on distance traveled and path off the end rail. Hit the side pocket too many times.


As far as your “at least three LD shaft makers have told me” line, you’re gullible as hell then. It’s called sales marketing. Figuring out what terms can be said without people questioning the statement. But since you can’t figure out that speed plays a role in deflection, a LD shaft is for you.

You could have made your statement without taking shots at me. Thanks for "gullible" knock.

 

[qbilder]

I gave my mechanical engineering view to Royce for a quite a bit 10-15 years ago on why the term "tip end mass" isn't really accurate for the collision dynamics . I've also explained it on these boards a half dozen times, but it normally gets dismissed apparently by all these wonderful people who don't know a thing about collisions. But, in the future, when everyone suddenly understands why "tip end mass" isn't the right term, everyone else will take credit, and they'll all educate me (us) about it.

So, I don't talk about it anymore. Fuggit.


Freddie <~~~ ain't talking no more, and off to the bar with my ball

Hear hear :deadhorse:

 

[Cornerman]

Freddie,

By “tip end mass,” do you mean the same thing as shaft endmass?

For those interested, the what causes squirt resource pages covers this topic in detail.

Enjoy,
Dave

Yes. And lots of those details are the same things we’ve talked about about for a zillion years. If we stop saying “shaft end mass,” maybe those who might be willing to try and have the skills to execute other concepts just might get other shaft designs off the floor.

I’m sure you can find my posts on this subject.

 

[Cornerman]

Who pee'd in your Wheaties? I'm just going by what at least three LD shaft makers have told me. Whatever the reason, its obvious after about five shots that when using side-spin an LD shaft will keep the cueball closer to your target line. If you've made post on why they really do/don't work send me link and i'll gladly read it.

Nothing about my posts suggest that LD shafts don't do wha they do.

It's tough to have a conversation with you if you're arguing against something that I never said.

What I did talk about longer than any other mechanical engineer (to the bet of my knowledge) is the "what causes squirt" based on what the Jacksonville Project videos showed. I believe I was the first to publicly talk about the transverse wave propagation and it's direct relationship to squirt. And yes, that would be several years before our great Dr Dave (and I do mean great) entered the foray of internet science billiards.

If you understand this in engineering terms, then you'll know that "shaft end mass," though a simple thing to say, is not wholly correct.

If someone argues against that last sentence, then I take my ball away and go to someone like the late Royce Bunnel so he can use his skills as an engineer and a cue builder to examine what else he can do with a cue to satisfy "what cause squirt."

None of this is new, so anyone can search or talk to me. I've had this same discussion with many science and cue builder pool folks, as I have a close connection with both, as a career engineer and one of only a handful of cue authors. Royce was one of the few cuemakers that had both skill sets. Too often, if a person has one or the other, the ideas get poo poo'd, which is rather ridiculous and ironic.

 

[qbilder]

Post #2:http://forums.azbilliards.com/showthread.php?359199&p=4678437#post4678437 Looks like we're kinda on same page. That is you, right?

I do not appreciate the gotcha games, and I refuse to play. If that's your goal, then this conversation is moot. Not that I should have to explain, but as with typical of humans, my opinion is subject to evolve as understanding & knowledge grows. That's what we call an open mind.

Deflection is a pretty straight forward physics concept, and testing should be pretty straight forward as well. The tests we see being used to measure cue ball deflection seem definitive enough......until you remove chalk. If it's a test of deflection, the test should be performed both with and without chalk, and yield the same results. If it cannot be, then we are missing something. It's that simple. There's something more going on than is being given credit. Until we can quantify & factor the effect of chalk, then how reliable can the testing be?

 

[qbilder]

Fred or Dave either one, would you care to explain why deflection is altered with chalk? Should testing with and without chalk yield identical results if deflection is all that's being measured?