Deflection, Endmass and Shaft Design

[td873]

Now this is interestng...I have always considered the throw and squirt on the object ball and the resultant path of the cueball intrinsically related...different sides of the coin, so to speak...please explain.

Hitt,

The concept of the Meucci test [pronounced May-yucky where I'm from ] is to illustrate a particular shaft's deflection by hitting a cue ball into an object ball, and measuring the object ball's 'deflection from 0°.' I believe that the Meucci tests show:

1) Iron Willie hitting a cue ball lined straight up at an object ball (this is laser sighted, with the center of CB lined up to the center of OB ->this is the 0° baseline)

2) Iron Willing hitting the cue ball off center, causing some degree of deflection, and further causing the cue ball to hit an object ball off center, and then

3) measuring the resulting offset from the 0° baseline that the object ball hits some contact paper. [The contact paper is placed at some defined distance from the OB's resting point] When the OB hits the contact paper, it leaves a mark, and the distance the mark is from the 0° line is the relevant measurement.​

*The assertion is: the larger the measurement is from the baseline, the larger the stick's deflection must be.

*I think the point being made is that this experiment does not take into account the change in the OB departure angle that results from the english on the cue ball, i.e., object ball throw. In particular, there may be some correlation between the amount of angular velocity on the CB and the OB contact point that this experiment fails to account for. In particular, if the CB has more spin, the OB will throw more - effectively reducing the measured contact distance -> indicating less deflection of the cue ball. With less spin on the CB, the calculated deflection amount would be greater relative to the "faster spinning cue ball."

*One point of contention [This is not a perfect example, but illustrates the point]:

suppose two shafts have the exact same deflection characteristics, but the tip's have different chalk on them (say Master's and generic). The measured distance of the OB may be smaller simply because the Master's chalk spins the cue ball better, resulting in more OB throw.​

However, FWIW, the variation caused by OB throw may not be measurable in the short distance the balls travel, and also due to the precision of the experiment. Whether it is definitive or not, it is another piece of the puzzle...

-td

 

[vapoolplayer]

The thing that amazes me is the control and verbiage used in all of his posts but if any of you read the PM that Drivermaker is talking about you'll see a whole new side to DoomCue.
Why not just be yourself for everyone to see?
Someone posted in another thread that you shouldn't use your own name on the forums because there are some sick fu*ks out there.
Well, I've just added DoomCue to that list and understand now why that person wrote what he wrote.

Koop

well...........i have reviewed the above mentioned material and have made my diagnosis of the situation..........

this guy is one sick fuck...........seek help immediately.

didn't someone just ask why people post annoymously on here???? maybe DM should forward this material to that guy.

VAP

 

[DoomCue]

Seems that some people think it's ok to attack people in a PUBLIC forum, but doing the same in private, where it belongs, is not ok. I try not to air my dirty laundry out in public like some people do. What transpired between drivelmaker and me in a past thread was a regrettable incident on my part (I know drivelmaker has no regrets - he lives for it). I apologize for what did make it to the public forum in the aiming thread a while back. However, I ABSOLUTELY WILL NOT apologize for what was thrown between me and drivelmaker in PRIVATE. My PM's to him started as a result of direct attacks on me personally in the public forums. I'd suggest reviewing the thread, but Mike deleted most of it. I took the squabble between drivelmaker and me behind closed doors. Drivelmaker's choosing to share that communication with others is just another sign of his paranoid insecurity. The communication between me and drivelmaker was NOT a one way street - there was an entire series of PM's, so all the drivelmaker sycophants need to keep that in mind.

BTW, drivelmaker, my promise is to Mike and has absolutely nothing to do with you. Stop being so paranoid and narcissistic - the world doesn't revolve around you.

Yet again drivelmaker, you've managed to try to deflect the topic away from your inability to admit you're wrong.

For VAP, the main reason for anonymity is so people can do/say whatever they want without having to suffer any repercussions. There are plenty of things which would never be said in this forum in a face to face conversation. Whether or not that's a good thing is up for debate.

-djb

 

[vapoolplayer]

For VAP, the main reason for anonymity is so people can do/say whatever they want without having to suffer any repercussions. There are plenty of things which would never be said in this forum in a face to face conversation. Whether or not that's a good thing is up for debate.

-djb

i guess everyone has their reasons...........i have mine, which aren't any of the above listed.

thanks

VAP

 

[drivermaker]

What transpired between drivelmaker and me in a past thread was a regrettable incident on my part (I know drivelmaker has no regrets - he lives for it). I apologize for what did make it to the public forum in the aiming thread a while back. However, I ABSOLUTELY WILL NOT apologize for what was thrown between me and drivelmaker in PRIVATE. My PM's to him started as a result of direct attacks on me personally in the public forums. I'd suggest reviewing the thread, but Mike deleted most of it. I took the squabble between drivelmaker and me behind closed doors. Drivelmaker's choosing to share that communication with others is just another sign of his paranoid insecurity.

-djb

Still trying, huh? LMAO Nobody is listening to you any more because they know what a psycho you are. You asked for it...you got it. Nothing would have happened if you had just shut your big mouth. I could care less if you live or pass on to the next dimension after this. But you can't help yourself...you're sick!

Once again...I DIDN'T POST TO YOU AND START THIS. YOU POSTED TO ME!!
IS THIS NOT SINKING INTO YOUR THICK SKULL??

You stop what you started, and so will I. That's a promise! I WILL NEVER RESPOND OR ANSWER TO ONE OF YOUR POSTS EVER ON THIS FORUM!!
Can YOU MAKE THAT STATEMENT ALSO?? Or will your rage and sickness continue??? We'll see shortly...won't we...then the rest of the guys can see for themselves.

 

[Matt_24]

I’m new here so I have not seen a lot of the discussions on deflection and shaft design…so for those of you who have followed this conceptually, please don’t let me confuse this issue with old and fully settled questions. Simply point me to the answer and I’ll get up to speed without troubling anyone. I was obliged recently to answer criticism heaped on one of my friends and customers for posting his new cue in the cue gallery and showing his exuberance. In the process, one fellow posted a link to an article on cue ball squirt that uses some quantified methods of physics and maths to explain the squirt phenomenon. For those of you who have not read the article the link is

http://www.sfbilliards.com/Shepard_squirt.pdf

I first heard the term “deflection” a couple of years ago and had to shake my head in disbelief at “the straining at a gnat while swallowing a camel” feeling I got at the explanation received. I have come to understand that the explanation was flawed but my impression has not abated. I posted this excerpt in the cue gallery and got no direct rebuttal so I decided to post it again, properly titled, to generate discourse and understanding.

I really enjoyed the referenced article...particularly enjoyed the methods. But I don't understand?...

"The parameter Mtip is not the total stick mass. Rather, it is the inertial resistance to sideways motion that the tip possesses. This effective mass Mtip is sometimes called the endmass...It is clear from the last expression that the individual endmass and ball mass values are not important, but rather it is only the ball mass to endmass ratio that matters."

It appears that the article is drawing an effective parallel between mass and inertial resistance to force...is this done so the reader may quantify additional values at some later date using this "mass" as a component for some kind of thrust calc that may actually define the curve of the resistance of different shafts?
What seems to be the prevailing conclusion from the methods of this study is that the value of "endmass" equals the weight of the tip or last 6" or so of the shaft and that this is the most significant factor in the actual resistance to sideways motion. I wonder if weight has so strong a correlation to this resistance as does, say, the material used, or better yet, the combination of the material and the chosen structure. Surely, at the level of establishing paramaters for initial consideration; weight may serve as a proxy for clarity but under more rigorous analysis of the elements, other factors would quickly show more promise as leading contributors to the phenomon. Particularly those whose results do not approximate experience. Possibly this is the source of the volume and voracity of the debate on this issue. If I set up a quick experiment where we take a given structure (1 unique shaft) and test its "inertial resistance to sideways motion" at the tip by measuring the "impulse" thrust required to move it a specified distance I think we would find that the location of the bridge/fulcrum would have a much greater effect on the "endmass" than adding or removing weight that might fall within the limits of reasonable possibility. My experience tells me that shortening up my bridge distance allows me to more accurately aim. I am a great believer in the scientific method and great admirer of those who follow it but it is not without its traps. A cursory study of history will provide ample evidence to support this.

As you may suspect, I take issue with several other premise forwarded in this article. We can address them another day in another thread.

- I wonder if Keith McCready ever wonders about this kind of thing......nahhh..he just runs out.

 

[Matt_24]

Does being a certified master BCA instructor automatically mean that you can play? You also forgot to mention that he writes a monthly science article for Billiards Digest...let's give credit where credit is due.

The question is can he put the ball in the hole for the cash!

 

[Matt_24]

Yes, I did figure it out on my own about 40 years ago. I do not own a Predator shaft. Mr. Kikel made my favorite shafts. Nothing like knowing what your cue will do. You want to know how to find out. Put a ball in the middle of the end rail on the rail. Shoot from the head spot. Make the frigging ball. You will find out real quick what squirt and deflection is all about. The shaft deflects and the c ball squirts. Is that how it goes? I ain't trying to confuse ya now buddy. I wonder how these scientist play.
Purdman

What's up Don?

I always loved the Predator, but more because I like the taper and feel of the shaft...I could give two sh*ts about deflection. I'm enjoying this thread due to the trash talk, but reading all of the scientific commentary is about as exciting as watching grass grow. Why would you want to make pool so freakin' boring. Do you think Mosconi, Hall, Strickland, Reyes, etc, etc, etc...EVER sat down and talked about this kind of thing?? No..they just played.

 

[Fred Agnir]

In the mean time give me OHB, SJM, Willee, Rude Dog, VAP, LastTwo, Rodd, and all the guys who I missed that just make balls and know how to play or gamble.

Where do you fit in? Are you a player? A very good player? A REAL player? Where do I fit in? Does everyone have to be a REAL player to post here? If I can beat some of the REALLY good players on board, can I still post whatever I want?


Fred <~~~ member at AZBilliards for longer than most here

 

[Mungtor]

I'm enjoying this thread due to the trash talk, but reading all of the scientific commentary is about as exciting as watching grass grow. Why would you want to make pool so freakin' boring. Do you think Mosconi, Hall, Strickland, Reyes, etc, etc, etc...EVER sat down and talked about this kind of thing?? No..they just played.

Why does everybody who doesn't care feel the overwhelming need to post that they don't? Or that there are/were great players who never knew this stuff so therefore nobody needs to know it?

Some people like to know how things work and why things happen. Let them talk about it while you're out playing. If that's what makes them happy, how does it effect anybody else?

 

[TATE]

Where do you fit in? Are you a player? A very good player? A REAL player? Where do I fit in? Does everyone have to be a REAL player to post here? If I can beat some of the REALLY good players on board, can I still post whatever I want?


Fred <~~~ member at AZBilliards for longer than most here

Fred,

I remember that you gave up the Predator shaft a while ago -maybe a year ago. Are you still using a conventional shaft?

Were you able to find a conventional shaft you were comfortable with right away? Did you have to make big adjustments to it? Do you feel there are some shots you are more (or less) comfortable shooting with the conventional shaft versus the Predator?

I like my 314 and know I will not go back to a conventional shaft, at least not on my 60" cue, but I'm thinking of trying the "Z" to get as stiff as I can on a 30" shaft.

Chris

 

[Fred Agnir]

My position rises from a gut instinct that the weight/mass of the last few inches is not nearly as important as several other easily manipulated factors that may affect this resistance to sideways motion from which Mr. Sheldon derives his definiton of "effective mass" (in an attempt to fit the problem into known, proven methods).

Mr. Sheldon I presume is Ron Shepard?

I believe the transformation in his equations are simply putting the collision equations in vector form. That way he can measure angles using right angles ,law of sines/cosines, or simple trig. In the end, as a normal collision equation, the ratio of the masses seem to be the driving variable for the squirt angle.

Since the mass of the cueball is known, and if you measure the squirt angle (via video or carbon paper or whatever), then you can back calculate how much mass from the cue stick was in effect: the effective endmass. How a cuemaker manipulates how much endmass is effecting the collision without boring holes or de-coupling the ferrule from the collision is for a cuemaker to invent, I guess.

What other factors that are easily manipulated should be tested? Since I'm not a dynamics PhD, I have no idea other idea than the simple collision physics model, which seems to be pretty good.

For anyone else reading, using simple collision physics wouldn't be enough to label anyone as a "science type." That'd be like calling someone who wears sneakers an athlete.

Fred

 

[Fred Agnir]

Fred,

I remember that you gave up the Predator shaft a while ago -maybe a year ago. Are you still using a conventional shaft?

I put down the low squirt shaft in September. I switch between my Andy Gilbert and my Schulers with Professional Taper (which is what I shot with before)

Were you able to find a conventional shaft you were comfortable with right away?

Pretty much right away. Like within minutes.

Did you have to make big adjustments to it?

Well, I had to shoot as I shot before: with the aim and pivot. Adjusting to the increase in squirt wasn't an issue, if that's the question.

Do you feel there are some shots you are more (or less) comfortable shooting with the conventional shaft versus the Predator?

I'm more comfortable on all the shots with a conventional shaft. The speed control and swerve judgement is more natural for me with a conventional shaft. That's what I never got used to with the low-squirt shaft. But I did give it a try. If I played with a low-squirt shaft for 15 years, I probably would have gotten used to it, but I couldn't see the benefit especially after picking up a conventional shaft and immediately having the good feeling.

There is a particular shot that I was able to make more consistently with the low-squirt shaft: slight jacked up firm. Probably because I have a flaw in my jacked-up stroke. But, one shot vs. 99% of comfortability is a no brainer.

Fred

 

[Fred Agnir]

I wonder how these scientist play.
Purdman

Like everyone else.

Fred <~~~ Reno bound next week

 

[DoomCue]

I'm getting ready to undergo a similar experiment to Fred's. I've been using my current shaft for about 6 years now, and I'm ready to try something new. I've been mostly anti-Predator, not because I don't believe it reduces squirt, but because of the fundamental change required of someone who is used to shooting with a "regular" shaft. Anyway, I'm going for a pretty big change. I currently use a 13.5 mm pro taper shaft which is super stiff. I've ordered a Predator Z, which is an 11.75 mm shaft with a Euro taper. I have no doubt that my quality of play will suffer for at least a few weeks while I get used to the shaft's characteristics.

I normally subscribe to this line of thought: I'd rather learn new things with my old shaft than learn old things with a new shaft. However, I'm willing to take a short-term setback if it will give me long-term results. Hopefully, I don't come to the same conclusion which Fred came to, cause I plan to sell my current shaft as soon as my new one arrives.

-djb

 

[TATE]

I'm getting ready to undergo a similar experiment to Fred's. I've been using my current shaft for about 6 years now, and I'm ready to try something new. I've been mostly anti-Predator, not because I don't believe it reduces squirt, but because of the fundamental change required of someone who is used to shooting with a "regular" shaft. Anyway, I'm going for a pretty big change. I currently use a 13.5 mm pro taper shaft which is super stiff. I've ordered a Predator Z, which is an 11.75 mm shaft with a Euro taper. I have no doubt that my quality of play will suffer for at least a few weeks while I get used to the shaft's characteristics.

I normally subscribe to this line of thought: I'd rather learn new things with my old shaft than learn old things with a new shaft. However, I'm willing to take a short-term setback if it will give me long-term results. Hopefully, I don't come to the same conclusion which Fred came to, cause I plan to sell my current shaft as soon as my new one arrives.

-djb

When I switched from a high squirt conventional to a 314, it felt odd at first. The first thing I noticed was the lack of weight at the front. This slightly changes the balance of the cue. It also changes the hit a little - mostly apparent on soft shots, particularly with english.

However, I realized performance advantages right away, particularly on long english shots. I found it to be much easier to not only aim these shots, but to also better judge the direction the cueball took off the rail. As a result I found myself using whatever english I needed on more and more difficult shots. I started using inside a lot more precisely which added a nice dimension to my shape game.

It took me a few weeks to feel like I knew the 314 well, a few months to know it very well, and now after over a year it's like a body part. However, if I screw on the conventional shafts (on my JW) I just can't play at the same speed. I notice a substantial difference between the shafts. For some reason with my stroke the Predator works well and i feel like I can't "swing away" with the conventional shafts like I do with the 314.

Let me know how you like the "Z". Since you're used to a strong taper I have a feeling your adjustment period is going to be short.

The other thing is, I do not like hard tips on a Predator. I tried all kinds of tips. I'm using an Elkmaster now. Even though it's a pain to break them in, man they work like a charm on my Predator.

Chris

 

[DoomCue]

Let me know how you like the "Z". Since you're used to a strong taper I have a feeling your adjustment period is going to be short.

Chris

You have no idea how much I hope you're right . I have several tournaments coming up, including a US Open qualifier. I hope this thing comes with an EASY button....

-djb

 

[Fred Agnir]

It also changes the hit a little - mostly apparent on soft shots, particularly with english.

This is one area that I just couldn't overcome my natural tendencies with the low-squirt shafts.

I started using inside a lot more precisely which added a nice dimension to my shape game.

I believe this is the reason that it didn't dramatically make a difference in my game. I already was very comfortable using inside english. I think the majority of pool players stay away from inside english (and it's due primarily to not fully understanding squirt and swerve).

So, I honestly think that those who already have the firm inside-english shot in their game won't find anything super advancing in their game in switching to a low-squirt shaft. Those that don't have a handle on pounding english (inside or outside) may reap immediate benefits, giving merit to the technology. YMMV.

Fred <~~~ still consistent with this idea

 

[HittMan]

Hitt,
The concept of the Meucci test [pronounced May-yucky where I'm from ] is to illustrate a particular shaft's deflection by hitting a cue ball into an object ball, and measuring the object ball's 'deflection from 0°.' I believe that the Meucci tests show:
1) Iron Willie hitting a cue ball lined straight up at an object ball (this is laser sighted, with the center of CB lined up to the center of OB ->this is the 0° baseline)

OK...

2)Iron Willie hitting the cue ball off center, causing some degree of deflection, and further causing the cue ball to hit an object ball off center, and then

OK...

3) measuring the resulting offset from the 0° baseline that the object ball hits some contact paper. [The contact paper is placed at some defined distance from the OB's resting point] When the OB hits the contact paper, it leaves a mark, and the distance the mark is from the 0° line is the relevant measurement.

OK...This makes sense

*The assertion is: the larger the measurement is from the baseline, the larger the stick's deflection must be.
*I think the point being made is that this experiment does not take into account the change in the OB departure angle that results from the english on the cue ball, i.e., object ball throw. In particular, there may be some correlation between the amount of angular velocity on the CB and the OB contact point that this experiment fails to account for. In particular, if the CB has more spin, the OB will throw more - effectively reducing the measured contact distance -> indicating less deflection of the cue ball. With less spin on the CB, the calculated deflection amount would be greater relative to the "faster spinning cue ball."

OK...If I understand you, I think this correlation is the "two sides of the coin" I'm talking about.

*One point of contention [This is not a perfect example, but illustrates the point]:

suppose two shafts have the exact same deflection characteristics, but the tip's have different chalk on them (say Master's and generic). The measured distance of the OB may be smaller simply because the Master's chalk spins the cue ball better, resulting in more OB throw.​

However, FWIW, the variation caused by OB throw may not be measurable in the short distance the balls travel, and also due to the precision of the experiment. Whether it is definitive or not, it is another piece of the puzzle...

-td

That's amazing...thanks for the explanation and the energy expended to give it...at least I have that in the 'ol database now. We try to keep things simple and really don't talk about "them" in polite company down here.

 

[Fred Agnir]

That's amazing...thanks for the explanation and the energy expended to give it...at least I have that in the 'ol database now. We try to keep things simple and really don't talk about "them" in polite company down here.

FWIW, Iron Willie is Predator and Clawson Cues' robot.

The Myth Destroyer is Bob Meucci's aparatus.

Again, FWIW, here's a post. Keep in mind that I'm talking about ways to falsely increase the effective endmass (which is what I believe Meucci's "robot" is doing):


http://www.billiardsdigest.com/ccbo...ard=ccb&Number=177154&page=&view=&sb=&o=&vc=1

Fred