History behind LD shafts

[Bob Jewett]

But I doubt that a transverse wave has much to do with it. ...

It is the transverse wave that is involved in sideways movement. I think the simple theory says that the fundamental mode of transverse oscillation (which you see when you whack the stick on the side and watch it wiggle back and forth with two nodes) gives the speed of the wave (after taking the right ratio of length divided by period) and only the part of the cue that can be reached at that speed while the tip is on the ball can give resistance to sideways motion.

The speed of the transverse wave is much, much smaller than the speed of the longitudinal wave (compression wave) that puts energy into the cue ball. You can get a feel for this by noting how much force is required on the side of the stick to bend it a quarter inch and then how much is required on the tip to compress the stick a quarter inch.

Since the transverse wave is slow, the tip "sees" only a small part of the cue stick while the tip is on the ball in the sideways direction. By contrast, the entire stick has time to compress during tip-ball contact because the longitudinal wave is very fast. According to the CRC Handbook, the speed of sound in maple is over 4000 meters/second along the fibers while ash is about 10% higher. That alone defines the speed of the compression wave, pretty nearly.

For the transverse wave the speed is a more complicated function of the cross section of the stick -- a thinner stick should have a lower resonant frequency and so a lower speed of sound for the wave.

Note that if you had a cue stick so long -- say 40 meters -- that the compression wave could not get to the end of the butt during tip contact, the cue ball would "see" only part of the weight of the stick.

Just as the cue stick "rings" sideways after an off-center hit (at about 40 cycles per second, IIRC), the stick also rings lengthwise after a center-ball hit with the tip going toward and away from the departing cue ball. This is visible in the high-speed videos on the Russian site because their equipment is fast enough and close enough to see the very small longitudinal oscillations.

 

[KMRUNOUT]

My thoughts on LD shafts....

It's true...a lot of people out there just fail to comprehend what the differences are with LD shafts. No amount of scientific evidence will alter their opinion. It's a fact that LD shafts do what they do, but so many just refuse to believe. I guess ignorance is a prerequisite of being a sucker...

KMRUNOUT

 

[Jal]

It is the transverse wave that is involved in sideways movement. I think the simple theory says that the fundamental mode of transverse oscillation (which you see when you whack the stick on the side and watch it wiggle back and forth with two nodes) gives the speed of the wave (after taking the right ratio of length divided by period) and only the part of the cue that can be reached at that speed while the tip is on the ball can give resistance to sideways motion.

The speed of the transverse wave is much, much smaller than the speed of the longitudinal wave (compression wave) that puts energy into the cue ball. You can get a feel for this by noting how much force is required on the side of the stick to bend it a quarter inch and then how much is required on the tip to compress the stick a quarter inch.

Since the transverse wave is slow, the tip "sees" only a small part of the cue stick while the tip is on the ball in the sideways direction. By contrast, the entire stick has time to compress during tip-ball contact because the longitudinal wave is very fast. According to the CRC Handbook, the speed of sound in maple is over 4000 meters/second along the fibers while ash is about 10% higher. That alone defines the speed of the compression wave, pretty nearly.

For the transverse wave the speed is a more complicated function of the cross section of the stick -- a thinner stick should have a lower resonant frequency and so a lower speed of sound for the wave.

Note that if you had a cue stick so long -- say 40 meters -- that the compression wave could not get to the end of the butt during tip contact, the cue ball would "see" only part of the weight of the stick.

Just as the cue stick "rings" sideways after an off-center hit (at about 40 cycles per second, IIRC), the stick also rings lengthwise after a center-ball hit with the tip going toward and away from the departing cue ball. This is visible in the high-speed videos on the Russian site because their equipment is fast enough and close enough to see the very small longitudinal oscillations.

I'll have to re-familiarize myself with technical treatments (e.g., Euler-Bernoulli, although that's for the static case), before commenting much further. At this point I'm confused by what seems to be a contradiction. If the transverse wave were extremely slow, for instance, then if I'm understanding your comments, only a very short length of stick behind the tip would be able to move to the side. But this should make for a very stiff stick at the same time, just as a shorter cantilever (all else being equal) equates to a larger effective spring constant (more lateral resistance) and therefore more squirt.

Yet, if the ball squirts more, conservation of momentum dictates that more stick mass will be set into motion in the opposite sideways direction (or less mass with greater velocity, but that doesn't seem to be an option), contradicting the "premise" that a shorter length of stick is pushed aside?

As indicated, I obviously need to go back to school on this, but any further clarification would be appreciated.

Jim

 

[Jal]

Although I think exactly the same as you, looks like endmass is an order before flex in terms of squirt. Like you, I can't imagine it graphically in my mind, but that is what it is

Is it? (Could be we're both geniuses and onto something)

Jim

 

[Bob Jewett]

... go back to school on this, ...

I looked briefly for videos that would be helpful but didn't find any that really stand out. Evidently the slinky is the standard demo tool for waves and it's transverse and longitudinal waves are very similar in velocity.

 

[KMRUNOUT]

So if I took a piece of re-bar and stuck a leather tip on it, then took a really long pencil, and put a tip on it as well, then hit a cueball with each using left hand english... according to you, both the re-bar and pencil would deflect the same amount off the cueball? I'm no science whiz, but from the basic principles that I have come to understand, the re-bar would transfer more energy than the pencil, and would not deflect off of the cueball as much as the pencil... If there are numbers out there to quantify this, I'm all ears. I just don't see how this is inaccurate. It may be exaggerated, but not inaccurate.

Thanks for the friendly banter PJ.

I don't think you are accounting for the fact that a pencil-diameter rod of rebar would weigh considerably more than a shaft length pencil. I think if you reduced the diameter of the rebar to the point at which its mass was equal to the pencil, my guess is the shaft deflection would be more similar. Sounds like a fun project lol.

KMRUNOUT

 

[KMRUNOUT]

That was the idea. I've been thinking lately that I might want to try the smallest production tip - would that be Predator's 11.75mm Z2?

pj
chgo

PJ,

I believe the new Meucci shafts offer one called the "Ultimate Weapon", which is 11.5mm. I tried the 12.625 mm version of the same and it was awesome. Great feel, very low squirt, and the sensation that I could spin and move the ball more easily with less tip offset. I don't know what would cause this last feeling mentioned...but there it was. I liked it a lot and considered getting it.

KMRUNOUT

 

[Cornerman]

But I doubt that a transverse wave has much to do with it.

Jim

This is one of those known concepts from 15 years ago. The slow transverse wave propagation is the key to understanding and start defining how much mass is in effect during the tip/ball collision. Without this understanding, the "tip end mass" idea means very little since one needs some idea of how far down the shaft is included in "tip end mass." The full term is in boldface.

Maybe your discussion on stiffness is a semantic one. But, overall shaft stiffness is not a parameter in the shaft mass in effect during tip/ball collision.

Freddie

 

[MalibuMike]

A Shill? You been watching Spinal Tap too much!

MalibuMike, you're a shill for Tiger. We get it.

With respect, please contribute something that's meaningful and not just an advertisement. Or leave.

A Shill for Tiger? And thats why all 3 of my cues are Schon's? Yeah, I see the logic in that, its like a clever little twist then isn't it?

 

[galipeau]

I guess I read you wrong when I posted that. Sorry for calling you a shill. I can retract that post if you wish.

 

[MalibuMike]

No Worries...

I guess I read you wrong when I posted that. Sorry for calling you a shill. I can retract that post if you wish.

By the why, what is a shill?

 

[galipeau]

Someone who tries to sell a product that claims to be unrelated to the seller/maker.

Maybe you're just a big fan of Tiger products, and that came across as a sales pitch in your writing to me. Tiger makes good stuff, but from what I've seen so does OB, which you seemed to dislike.

 

[MalibuMike]

I was kidding, I know what a shill is.

Someone who tries to sell a product that claims to be unrelated to the seller/maker.

Maybe you're just a big fan of Tiger products, and that came across as a sales pitch in your writing to me. Tiger makes good stuff, but from what I've seen so does OB, which you seemed to dislike.

I have the new OB Pro +. and it’s the best shaft that OB has come out with yet. The only reason I'm so ardent about the Tiger Pro-X is it that it is basically the same as OB's new Plus line. Tiger is from my hometown and has been making this shaft for years and OB comes along and basically gets rid of their hollow front-end design and copies Tiger. It's just wrong. But I guess that’s how business works nowadays. I see these people saying that these companies who are doing the most marketing, namely Predator and OB, make the best products. That’s simply not true. That’s just my experience.

 

[galipeau]

Interesting info. Thanks for sharing and expanding on your views.

 

[JoeyInCali]

I have the new OB Pro +. and it’s the best shaft that OB has come out with yet. The only reason I'm so ardent about the Tiger Pro-X is it that it is basically the same as OB's new Plus line. Tiger is from my hometown and has been making this shaft for years and OB comes along and basically gets rid of their hollow front-end design and copies Tiger. It's just wrong. But I guess that’s how business works nowadays. I see these people saying that these companies who are doing the most marketing, namely Predator and OB, make the best products. That’s simply not true. That’s just my experience.

OB did not have hollow front end. The whole shaft was hollow afaik.
They copied Tiger's ferrule configuration ?
Tiger's design is actually not low-end mass afaik.
The Saber-T ferrule and stem is fairly heavy and hard .
I don't know if that qualifies to be a low-squirt shaft.
It is heavier ( in the front ) than the normal maple shaft with tenoned ferrules.

 

[RBC]

I have the new OB Pro +. and it’s the best shaft that OB has come out with yet. The only reason I'm so ardent about the Tiger Pro-X is it that it is basically the same as OB's new Plus line. Tiger is from my hometown and has been making this shaft for years and OB comes along and basically gets rid of their hollow front-end design and copies Tiger. It's just wrong. But I guess that’s how business works nowadays. I see these people saying that these companies who are doing the most marketing, namely Predator and OB, make the best products. That’s simply not true. That’s just my experience.

Mike

Here we go again, you talking about things as if you know what you're talking about when you really don't.

First of all, the + in our new line of shafts is all about the splice and has nothing to do with the LD characteristics of the shaft. All + models do have an open bore at the tip end, so If Tiger's shaft does not, then we certainly could not have copied them. All the + shafts use our patented splicing method, and I can assure you that it's nothing at all like what Tiger builds. Tiger builds great products, but they are different than ours.

I'm sorry, but you're conclusions are simply not correct. Please stop with all the talk about us copying Tiger or provide something to back it up.

Royce Bunnell
www.obcues.com

 

[SilverCue]

I had Richard Black make me a cue back in 1978 and when it arrived it came with a little Xerox sheet of paper maybe two pages long..like a folded brochure in the old days. It was titled something like "The Care and Feeding of a Fine Pool Cue" and it was written by Richard Black (or one would assume, because his name was titled on it).

He told how to clean the cue, wrap, etc...simple stuff concerning taking care of the cue. There also was a bit about cue construction I think and something about ivory ferrules and there was a paragraph or so and if I can remember correctly I think he used both terms "deflection" and "squirt" in it and in the manner it was written it suggested that it was a theory of some cue makers. At the time, Richard's standard cues all came with two shafts and ivory ferrules (unless you requested something else).

Nowhere in it did it say his cue were any lower deflection than anybody else's from what I can remember. I think that was the first time I ever heard either of the words used describing shaft characteristics.

I was going through some of my old pool stuff and came across Care and Feeding of a Fine Pool Cue by Richard Black.

I did a search and this is the only reference I could find.
Here is a PDF version.
It is 6 separate files because of size limitation.
5 are in this post and 1 will be in the next post.

Page 6
you will not be very happy about it.. But then here's
something most people wouldn't think about is, believe it or
not, the way you hit a ball, you have trained that piece of
leather on the tip. So, if you let somebody else hit with
your tip he's going to hit differently, and when you step
back up there to hit with that tip, that poor tip is thinking
"What happened to me, I was all trained and now I'm not, l'm all confused."
It'll respond differently; because he's got different facets built in there for different reasons
whether bone structure, muscles, whatever. So, you t re just
better off not to loan Your cue. .
Protect your cue, it's the best tool you own to Play better pool.

 

[HawaiianEye]

I was going through some of my old pool stuff and came across Care and Feeding of a Fine Pool Cue by Richard Black.

I did a search and this is the only reference I could find.
Here is a PDF version.
It is 6 separate files because of size limitation.
5 are in this post and 1 will be in the next post.

Thanks for posting that. It's been a long time since I've seen it. I'm surprised I still remembered the title after all these years.