ScottR said:I wish somebody would shoot this thread. I think Ralph Greenleaf just rolled over in his grave because he never got to use a Predator.
Naw he was just looking for a drink or rather another drink.
Deflection, Endmass and Shaft Design
- Thread starter HittMan
- Start date
Naw he was just looking for a drink or rather another drink.
drivermaker said:
No, I have actually never been to the site...but the firestorm thing isn't a bad idea if that is what it takes. You sound like you have already settled it with, say, apathy and/or aloofness...I, on the other hand, haven't gotten there yet...so let the big dogs eat...I'm just looking for the scraps.
Possibly I have chosen the wrong arena for this. oh yeah...who's JAM?
Oh Oh Yeah...you can bet I'll be going there soon.
drivermaker
Banned
HittMan said:
She posts here on AZ, and they're always good. She posted there also and got attacked by the "monkey clowns". Maybe you will also. Have fun......
HittMan said:
There are both theoretical reasons and experimental results that support the concept of "end mass." Those have been discussed over in RSB quite a bit.
But let's try the scientific way: can you suggest an experiment that we could both do that could disprove Shepard's proposals?
TATE said:
OK OK ... This is what I'm talking about...I'm not a rocket scientist either...I just don't think we're comparing apples to apples. You keep suggesting that i add something heavy to the end of my shaft...I keep countering that something as heavy as a brass screw is outside what I think is the relevant range of consideration. So, let's work with that for a moment...if you drill a .325 hole in the end of your shafts to say a depth of 4", how much weight have you removed? I can say with relative safety that it will not be more than 4 grams if you assume a density of 12 grams per cubic inch. Now take that 4 grams and lay it on the side of a shaft and measure the amount of deflection it causes...then get some weights and pile it on the shaft until you get the amount of deflection that you might normally see in a hard side english shot (whatever that amount may be...considerable in my estimation). Now...compare the two amounts...I think you will find that the 4 grams is dwarfed (to insignificance) by the other weight...let's say to 10%...maybe less. Now compare that to the alternative of something simple like, say, reducing the diameter of the shaft or lengthening the taper or increasing the length of the fulcrum (bridge) or etc. I'm not denying the phenomenom...I asking if the weight in the last few inches of the shaft is really significant when you look at the whole structure and other common sense alternatives.
You realize that every shaft buckles and this is what I don't get. I repeat...I have not studied the intricacies of collision physics...I just don't agree with the transformation presented without some evidence.
Anyway...thanks for your thoughts.
F
Fred Agnir
Guest
HittMan said:
Clear your mind of any preconceived notions. Start with simple collision physics. "Effective endmass" is simply the mass in the equation for simple collision. You already know what the mass of the cueball is.
I can't say it any simpler. Visit a Physics 101 book.
Fred
F
Fred Agnir
Guest
I don't know why you're so antagonistic towards these two. I'll turn it around on you. What would you consider a skill level worthy such that you wouldn't say that they "couldn't play a lick"?drivermaker said:
I'll ask someone else to find the posts where Bob Jewett reports his high run. And I've played against Ron Shepard. He's no professional, but he's a very good player. 100 in NPL, 7+ in APA (if he played it), and good shot at Master Level in BCA.
Oh, and FL is delusional. Why you would believe any of his exaggerations is mind boggling.
Fred
Purdman
Banned
This is on the net
SQUIRT
Cause – When a cuetip strikes the cue ball off center it does not slide across the ball due to the high friction created by the chalk. Instead the stick is married to a particular point on the cue ball for the fraction of a second the tip and ball are in contact. During this contact time the cue ball is beginning to spin sideways. This means the the tip-ball contact point has to move away from the center of the cue ball which can only occur if the cue ball or the stick or both begin to move slightly to the side (in addition to their forward motion). In real life, both occur causing the stick to deflect to the side a bit and the cue ball to squirt.
Factors That Influence The Amount Of Squirt
greater offset from center of cue ball = more squirt
higher effective end mass of the cuestick = more squirt
slicker cloth = more squirt
flexibility of stick = no consistent relationship with amount of squirt*
speed of shot = no effect on squirt*
Notes About Squirt
Experimentally, it has been found the effective end mass of the cuestick is mostly determined by the mass of the tip, ferrule, and the final six inches or so of the cuestick. High speed photography by Jewett and others have found the time of contact between cuestick and cue ball to be about .001 seconds or slightly more.
Does this help anyone or just me?
Purdman
SQUIRT
Cause – When a cuetip strikes the cue ball off center it does not slide across the ball due to the high friction created by the chalk. Instead the stick is married to a particular point on the cue ball for the fraction of a second the tip and ball are in contact. During this contact time the cue ball is beginning to spin sideways. This means the the tip-ball contact point has to move away from the center of the cue ball which can only occur if the cue ball or the stick or both begin to move slightly to the side (in addition to their forward motion). In real life, both occur causing the stick to deflect to the side a bit and the cue ball to squirt.
Factors That Influence The Amount Of Squirt
greater offset from center of cue ball = more squirt
higher effective end mass of the cuestick = more squirt
slicker cloth = more squirt
flexibility of stick = no consistent relationship with amount of squirt*
speed of shot = no effect on squirt*
Notes About Squirt
Experimentally, it has been found the effective end mass of the cuestick is mostly determined by the mass of the tip, ferrule, and the final six inches or so of the cuestick. High speed photography by Jewett and others have found the time of contact between cuestick and cue ball to be about .001 seconds or slightly more.
Does this help anyone or just me?
Purdman
drivermaker
Banned
Fred Agnir said:
He's posting right here...ask him yourself or he could just chime in on his own.
Otherwise, go to Jewetts posts (under his name) here on AZ and you can find it yourself. I already know the answer, I just want to see if it changes from one place to another or over time.
BTW, in real life, FL isn't anywhere near what you think he is based on forum rants. He's a wild man here and elsewhere, but he's not delusional or insane.
Forums just do funny things to people.
drivermaker
Banned
Donald A. Purdy said:
It seems like everything in life comes down to those final six inches, huh?
All I want to know Don is...does this help YOU shoot any better or worse by knowing it? I didn't think so....because you figured it out about one year into your pool shooting career as a teenager without the internet and without the writings and experiments of a couple guys that love nothing more than turning the simplistic game of rolling balls with a stick into a physics thesis.
Did this also help you in making the decision to buy a 314 for each one of your cues and different joints?
Bob Jewett said:
Good Timing Bob,
I had just resolved to do just that. In the previous post I just laid out a comparison...I think the weight removed from the shaft calc is about right but I'm conjecturing beyond that. We all know what that will get you. So...what I will do is bore a shaft .325 to 4" (is that enough, too much?) and we can compare it to the weight required to deflect the shaft (say 12.75mm) to what dimension? I am new to this but I suspect that number may roll right off the tip of your tongue. All we have to do then is agree on some parameters and look at the results. Please feel free to conduct your own and we can compare. Possibly it would be good for one of us to select a tight grained shaft and the other a wide grain so we can get a broader view.
I would like to say again that I am not trying to disprove anyone...I am trying to understand how the weight in the last few inches is more significant than the material and the structure. I think the concept of endmass is sound as a beginning for a study of the structure. I also wonder if we (as a group) have seized upon a lesser variable (that is easily understood and quantified) and held it up as THE answer to a very difficult question. In the end, I simply am trying to make up my mind whether to make changes to my process to reflect this information. This is only one aspect of the pervasive constraint of cost/benefit which I generally apply to such decisions. I am, however, certain the buying public is willing to pay dearly for progress in this area. As we also know, wringing the last few advantages out of a performance problem is always quite expensive when compared to the simpler alternatives.
I suspect (my hypothesis is) we will find that inside the relevant range of shaft sizes (say 13mm to 11mm...tight for the bore), bridge lengths (say 2" to 14"), and materials (between wood and GRP) that would be of reasonable density (shafts between 90 and 150 grams) and entire structures (cues) between say 17oz and 21 oz of a length between 57 and 60 inches, the weight differential in the last 6" of the shaft will average no more than say 10% (I've already used this number so let's stick to it) of the total weight required to deflect the tip the desired amount.
Does this sound reasonable? Do you have suggestions?
I will get over to the RSB...I just got directions from drivermaker. Right now I have to go home to dinner.
Thanks for your reply.
drivermaker
Banned
Donald A. Purdy said:
Agreed.........
It is easy to get a gram or two of lead wire (or solder) and wrap it around the ferrule. No drilling required. It's a pretty interesting experiment. It is much less dramatic than the brass-filled shafts Jim Buss made to demo extreme squirt, though.HittMan said:
As for stiffness, and how it's involved, that's much harder to test. Theory says that if nothing else changed and the shaft were made stiffer, there would be more squirt because the stiffness is expected to increase the length of the shaft that participats in the sideways motion during contact. Unfortunately, I don't know of an easy way to change stiffness without changing anything else.
The current estimated length is about six inches which agrees generally with the speed of transverse waves (like a violin string) in the shaft and contact time, but I think we need a good mechanical engineer to fill in some of the details. I think the speed depends on the stiffness of the material, so if you had a stiffness knob to turn, a stiffer cue would give more squirt.
Gosh, Fred, I'm not sure why you're arguing with him or even reading his posts, but that's your call.Fred Agnir said:
My high run is 102 for whatever that's worth. I reported a run of 77 that I had recently in the semifinals of one of the 14.1 leagues I play in, and that may have been confusing to somebody.
If Grindinger is not delusional, he puts on a good immitation.
Purdman
Banned
drivermaker said:It seems like everything in life comes down to those final six inches, huh?
All I want to know Don is...does this help YOU shoot any better or worse by knowing it? I didn't think so....because you figured it out about one year into your pool shooting career as a teenager without the internet and without the writings and experiments of a couple guys that love nothing more than turning the simplistic game of rolling balls with a stick into a physics thesis.
Did this also help you in making the decision to buy a 314 for each one of your cues and different joints?
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
Bob Jewett said:
As for the stiffer equally more squirt I think it makes sense but how would that explain Meucci's. IMO they create a ton of squirt. At the same time they do not appear to be anywhere near as stiff as say a SW. Does that mean that the SW would deflect more and cause more squirt than a Meucci.
Does this corrolate at all with the amount of english someone can get on the ball. For some reason with a Meucci I seem to be able to get a tone of english on the CB. I have trouble getting consisent "pots" with the OB but loads of english. Why would this be?
I am just using Meucci as an example. I have played with other cues that seem to have alot of squirt to them as well.
Interestingly I just remembered that I once was called to play a league match while at work. I went over to play that match but did not have a cue so I borrowed by friends SW. He and I got quite a few laughs at me trying to make adjustments while playing due to the deflection. It had a very stiff hit
but it seemed like the ball squirted at least an inch or more on some shots.
Its all what you get used to in the end.
drivermaker
Banned
Donald A. Purdy said: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
No Donald...you aren't confusin' me and I knew damn well you didn't own a Predator shaft. Remember, we came up around the same time. If you recall, this is the way it went: you set up a shot and shoot it with some english and you miss. You say, "this piece of shit warped house cue...think I'll go find another one".
So you set up the shot again and you shoot with english and miss, so you say, "this piece of shit house cue is even worse...it has a flat tip that looks like a mushroom....think I'll go find another one".
So you set up the shot again and shoot with english and miss, so you say, "what the f*#k is goin' on here. I know I ain't that bad. HEY JIMMY... JIMMY ONE NUT...come here and help me with this shot, I keep missin'." So Jimmy comes over who is dumber than dog shit and quit school in the 10th grade but can shoot lights out pool and he says, "No wonder you keep missin' the shot you stupid little f*#k...when you put right english on it, the CB shoots to the left as soon as you hit it. When you put left english on, it shoots to the right. Aim a little more outside and you'll figure out how much".
And that's pretty much how it went, right? Problem solved.
BTW...if you want to know how the scientists shoot, I already told you. LIKE SHIT!! One scientist just keeps covering up for the other ones, and the other ones keep covering up the whole scam and that's the way that one goes too. All they want to do is keep writing more and more thesis to cover up the whole thing and get everyone to think otherwise.
Yes, to some extent this is true, but there are some cues that have so much squirt that they are really unreasonable to play with. You know the 90-degree cut of the ball frozen on the end rail? With some sticks and maximum side, you have to aim half a ball ON THE WRONG SIDE of the object ball. Yes, your aim has to be a full ball and a half over from where you want the cue ball to land. Some sticks are really that bad.frankncali said:
Some players like less squirt and some like more squirt and some have no idea what squirt is but they still play at the championship level.
Knowledge alone can't make you a better player, and lack of knowledge is not necessarily a barrier to fine play.