Platinum Billiards' deflection chart

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Gregory

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Apr 26, 2004, 2:41:18 AM4/26/04
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http://www.platinumbilliards.com/rating_deflect.php
Chart reflects squirt for an average 9 mm offset
over 50". Not sure, but probably the offsets were
measured to cue center line, which would correspond
to actual average offset (contact point) of 6.8 mm.
The lowest squirt measured was a Predator Z at
34.3 mm.

6.8 / 34.3 * 50 = 9.9" spp.

Seems like something is screwy.


Newsposts1

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Apr 26, 2004, 5:45:56 AM4/26/04
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"Gregory" <greye...@bellsouth.net> wrote in message news:<s62jc.6793$7a5....@bignews6.bellsouth.net>...

> Seems like something is screwy.

Yeah .... something is definitely awry .... but not for the reasons
you think.

Like all other tests for deflection, this one is fatally flawed
because it does not discuss impact velocity and changes in deflection
versus impact velocity.

The key to a decent cue is that its deflection characteristics stay
the same throughout a typical range of playing velocities.

IOW, with a tip offset of 6mm, the amount of deflection (whether large
or small) should be very consistent as the impact velocity varies from
some value "x" to "1.25x", "1.5x" and so on up to about "2x" or "3x".
The minimum value of "x" would have to be some minimum velocity where
the effects of swerve are more or less insignificant in the
measurement.

I have no doubt whatsoever that many of these cues would have
deflection varying quite a bit with velocity. It is inherent in their
designs.

Until people look at and compare the relationship between deflection
and velocity, the test results are nothing more than a farce and a
marketing ploy (for Predator in this case because it is at the top of
the list).

This one is just another in a long and growing list. The data are
meaningless.

Carter Adams

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Apr 26, 2004, 11:13:46 AM4/26/04
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"Gregory" <greye...@bellsouth.net> wrote in message news:<s62jc.6793$7a5....@bignews6.bellsouth.net>...

I don't follow your math. What is spp ???

It looks to me that the Predator Z had about 1.35" of squirt at 50" - not bad...

~Carter

Ron Shepard

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Apr 26, 2004, 11:19:26 AM4/26/04
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In article <s62jc.6793$7a5....@bignews6.bellsouth.net>,
"Gregory" <greye...@bellsouth.net> wrote:

> http://www.platinumbilliards.com/rating_deflect.php
> Chart reflects squirt for an average 9 mm offset
> over 50".

They say that they use offsets of -12mm, -6mm, +6mm, and +12mm.
However, they don't say which offset was used to produce the table,
and as you point out, it is not clear if the offset is for the tip
contact point, the shaft axis, or the inside of the shaft edge.
This is why they should report the results in terms of pivot points
rather than distances, it would eliminate all of this ambiguity.

> Not sure, but probably the offsets were
> measured to cue center line, which would correspond
> to actual average offset (contact point) of 6.8 mm.
> The lowest squirt measured was a Predator Z at
> 34.3 mm.
>
> 6.8 / 34.3 * 50 = 9.9" spp.
>
> Seems like something is screwy.

Even if you assume the maximum of 12mm offset for the results in
their table, the pivot point would be 17.6 inches for their
low-squirt shafts, which is at least a factor of two too small
compared to human pivot point measurements. It would be nice to
know the details.

$.02 -Ron Shepard

Stephen

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Apr 26, 2004, 2:11:32 PM4/26/04
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Ron Shepard wrote:
> They say that they use offsets of -12mm, -6mm, +6mm, and +12mm.
> However, they don't say which offset was used to produce the table,

In paragraph 2 they said they used the average of the four shots. I
would have preferred to see all of the data rather than an average. It
would be interesting to see whether the deflection was consistently
proportional for 6 and 12mm offsets for the various shafts.

Some questions I would want to answer would be:

1. Would one shaft have higher deflection at all offsets than another
shaft?

2. Is deflection linearly proportional to offset?

3. If shaft A has x times more deflection at 12mm than at 6mm, does
shaft B also have x times more deflection at 12mm than 6mm?

In short, what is the relationship of deflection vs offset for one shaft
and is the relationship the same for all shafts? Show me that test data!

Steve (Newsposts1) has a valid set of questions on speed vs deflection
for any particular shaft. It would be more useful to know the
relationships of speed and offset vs deflection for a particular shaft
than average deflection for a survey of shafts at one speed. This would
cut down on the experimentation and help me predict how much deflection
I am going to get before I shoot. Isn't that the reason we really want
to know any of this?

That the difference between the best and the average shaft was only 25%
was interesting. Even if we all ran out and bought an armload of brand
Predator shafts, we still do not know how they will behave. I have
heard the argument that since Predator shafts have so much less
deflection it is easier to learn how to compensate. In fact, the same
questions apply to learning deflection of any shaft.

Stephen

Dan White

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Apr 26, 2004, 7:48:24 PM4/26/04
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"Stephen" <steely...@coldmail.com> wrote in message
news:ohcjc.17475$i61.17403@clgrps13...

> That the difference between the best and the average shaft was only 25%
> was interesting. Even if we all ran out and bought an armload of brand
> Predator shafts, we still do not know how they will behave. I have
> heard the argument that since Predator shafts have so much less
> deflection it is easier to learn how to compensate. In fact, the same
> questions apply to learning deflection of any shaft.
>

I know a very good player who just went back to his regular shaft after
giving the Predator shaft a good, long try. He said there were just some
shots that didn't feel "right." He couldn't really elaborate more than
that, but he didn't like the way they played.

dwhite


JoePisko

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Apr 26, 2004, 8:14:04 PM4/26/04
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Dan White wrote:

> I know a very good player who just went back to his regular shaft after
> giving the Predator shaft a good, long try. He said there were just some
> shots that didn't feel "right." He couldn't really elaborate more than
> that, but he didn't like the way they played.
>
> dwhite

Do you know if he was saying that he could not put enough spin on the ball
for certain shots or that he did not like the feel of the predators hit. They
do have a somewhat nebulous hit....
Joe

--
http://www.kudraband.com


Platinum Billiards

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Apr 26, 2004, 9:37:08 PM4/26/04
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> Ron Shepard wrote:
> > They say that they use offsets of -12mm, -6mm, +6mm, and +12mm.
> > However, they don't say which offset was used to produce the table,
>
>Greetings. The offsets we use are all based on the center axis of the
shaft. We feel that the average of the four shots gives a very good
number for each shaft. We could post, and we may, the separate
averages for the 12mm shots and for the 6's, but I can say that for
all the shafts we have tested thus far, the number we give is very
close to what they would produce at 9mm of offset, as the relationship
between offset and squirt is very close to linear. Sorry for the
confusion and we will try to improve the explanation of our methods on
the site.
--Steve Titus

Frank Glenn

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Apr 26, 2004, 10:20:40 PM4/26/04
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In article <ohcjc.17475$i61.17403@clgrps13>,
steely...@coldmail.com says...
:|:In paragraph 2 they said they used the average of the four shots. I
:|:would have preferred to see all of the data rather than an average.
:|:
I see their ad in BD has CW breaking with a Predator shirt on (page
43). Draw your own conclusions from this, but I think they are hyping
the P shaft. YMMV
Frank

Patrick Johnson

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Apr 26, 2004, 11:20:05 PM4/26/04
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sheldoncue wrote:

> Indeed, the lowest deflecting cue we have tested has eliminated only about ź
> of the deflection caused by the average cue.

I think the magnitude of difference in squirt among most cues is at
least 5:1 (say, 8 inches to 40 inches pivot length), which means that
the lowest squirt cues eliminate 80 percent (4/5) of the squirt caused
by the highest squirt cues and probably at least half of the squirt
caused by an average cue.

Pat Johnson
Chicago

Dan White

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Apr 26, 2004, 11:28:18 PM4/26/04
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"JoePisko" <joe...@comcast.net> wrote in message
news:408DAFF1...@comcast.net...
He didn't talk about spin or feel. It's funny because it was hard to get him
to elaborate on what he meant. He just kept coming back to saying that
certain shots just didn't feel right, and I think that the cue ball didn't
do what it "should." He had trouble with shotmaking on longer shots when he
got back to his regular shaft, but he adjusted to it pretty quickly, and was
hammering shots with no problem.

dwhite


Ron Shepard

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Apr 27, 2004, 12:15:52 AM4/27/04
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In article <108rkb6...@news.supernews.com>,
Patrick Johnson <patrick...@comcast.net> wrote:

> I think the magnitude of difference in squirt among most cues is at
> least 5:1 (say, 8 inches to 40 inches pivot length), which means that
> the lowest squirt cues eliminate 80 percent (4/5) of the squirt caused
> by the highest squirt cues and probably at least half of the squirt
> caused by an average cue.

I would think these numbers are about right for the range, although
I'd guess that the "average" pivot point is in the 12-16 inch range
though.

However, these values do not agree with the data at the Platinum
site.

$.02 -Ron Shepard

Gregory

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Apr 27, 2004, 2:12:30 AM4/27/04
to

Ron Shepard wrote

> However, these values do not agree with
> the data at the Platinum site.

Something in their method is yielding very
high squirt numbers across the board.


Newsposts1

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Apr 27, 2004, 2:56:18 AM4/27/04
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st...@platinumbilliards.com (Platinum Billiards) wrote in message news:<80ba6fc.04042...@posting.google.com>...

> Sorry for the
> confusion and we will try to improve the explanation of our methods on
> the site.

And what about the problems associated with not establishing a
relationship between deflection and impact velocity?

First of all, the cue ball must be sliding during the measurements to
prevent any false measurements due to swerve.

If the impact velocity is too low, then the cue ball is rolling and
swerve affects the measurement (towards a lower amount of deflection
that is actually there; the cue ball always wants to swerve back
towards the original target line).

The velocity must be at least above a certain threshold, which in turn
is dependent upon the condition of the cloth and balls (i.e.,
deflection is friction dependent to a certain degree).

Second, although some of the RSB die-hards scoff at the notion, impact
velocity also affects how the cue joint responds during impact, which
in turn affects how the shaft and tip move during impact.

If a suitable range of impact velocities (above the minimum threshold
for sliding vs rolling) aren't measured, then the results of any of
these kinds of deflection tests remain meaningless.

It's either that or continue with the blind belief that the all joints
are the same and/or the joint has no impact on deflection.

Both of these would be ridiculous conclusions based upon the
applicable mechanics and range of impact velocities possible in the
normal course of play.

Gregory

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Apr 27, 2004, 3:07:37 AM4/27/04
to
Carter Adams wrote
> Gregory wrote

> > 6.8 / 34.3 * 50 = 9.9" spp.
>
> I don't follow your math. What is spp ???

6.8 mm = amount of contact point offset from CB center.
34.3 mm = amount of CB squirt.
50" = distance across which the squirt is measured.
spp = squirt pivot point.

http://www.sfbilliards.com/faq.html
see #7

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

> It looks to me that the Predator Z had about
> 1.35" of squirt at 50" - not bad...

That's not good at all for a supposed low squirter.
Some Preds will squirt as little as .25" in 50" with a
6.8 mm contact point offset.


Newsposts1

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Apr 27, 2004, 3:15:22 AM4/27/04
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"Gregory" <greye...@bellsouth.net> wrote in message news:<s62jc.6793$7a5....@bignews6.bellsouth.net>...

> http://www.platinumbilliards.com/rating_deflect.php


> Seems like something is screwy.

This table is a marketing advertisement, in the guise of hard
scientific data, nothing more.

The platinumbilliardsDOTcom domain name is owned by Shane Sinnott, a
former sales/marketing associate for Clawson/Predator who has
apparently moved out on his own (not that there is anything wrong with
that).

The earlier post from platinumbilliardsDOTcom was from Steve Titus,
who originally patented the predator shaft tip design, and is the
former lead engineer for Clawson/Predator. He also has apparently
moved out on his own with Shane Sinnott (not that there is anything
wrong with that).

So take it that data for what it is worth, marketing hype and not hard
data. It is just like similar data on the Meucci site.

These kinds of tests are set up to provide numbers to indicate their
products are superior, and to sell more of that product. IOW, these
"answers" are to the benefit of the manufacturer and not necessarily
to the player.

The tests are not set up to provide comprehensive data sets from which
independent, accurate conclusions can be reached about the root cause
of deflection and how to prevent or minimize it. IOW, these answers
would be of benefit to the player and not necessarily to the
manufacturer.

John Barton

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Apr 27, 2004, 4:00:03 AM4/27/04
to
I don't neccesarily disagree with you but I have just one question?

If the Platinum billiards people are testing a LOT of different products
using the same set of conditions and just reporting on the results then
doesn't that show some form of impartiality?

In my opinion, it is a lot different than Meucci or Predator or even (gasp)
Instroke putting up their own data which shows their product to be superior
according to their tests. This is NOT to say that Meucci, Predator and
certainly not Instroke have skewed the tests to favor their products, but to
say that testing across the board by a company that otherwise just sells the
products is less likely to be marketing hype than whatever a company puts
out for their own products.

Okay, two questions, if the cues are all tested under the same conditions
would it not be fairly safe to assume that the performance numbers would
continue to show similar differences between cues when the variables are
changed. IOW, A high deflection shaft wouldn't become a low deflection one
through more velocity would it?

Goodness and good night.

John
www.cuecaserepair.com


"Newsposts1" <stev...@3cushion.com> wrote in message
news:52c1c1b1.04042...@posting.google.com...

JoePisko

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Apr 27, 2004, 7:33:04 AM4/27/04
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Dan White wrote:

>
> He didn't talk about spin or feel. It's funny because it was hard to get him
> to elaborate on what he meant. He just kept coming back to saying that
> certain shots just didn't feel right, and I think that the cue ball didn't
> do what it "should." He had trouble with shotmaking on longer shots when he
> got back to his regular shaft, but he adjusted to it pretty quickly, and was
> hammering shots with no problem.
>
> dwhite

That's funny, as a predator player I do not subscribe to the more spin argument
of their shafts. I have sat down with quite a few and find that the tip matters
more than the amount of squirt. If I get you right you are saying that he had
que ball position problems with it. That would seem to suggest that he was
getting the wrong amount of spin from it. That could also be from the crappy
lepro tips that come on predator shafts. I have been interested in why people do
not like these shafts, but far too often rather than giving a reason and any
sort of feed back they simply resort to creative sarcasm. I myself have never
been really enamored with the hit of them, but they seem to send the ball more
where I want it to go.
Joe


--
http://www.kudraband.com


JoePisko

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Apr 27, 2004, 7:46:10 AM4/27/04
to

Newsposts1 wrote:

> st...@platinumbilliards.com (Platinum Billiards) wrote in message news:<80ba6fc.04042...@posting.google.com>...
>
>

> And what about the problems associated with not establishing a
> relationship between deflection and impact velocity?
>
> First of all, the cue ball must be sliding during the measurements to
> prevent any false measurements due to swerve.
>

> Second, although some of the RSB die-hards scoff at the notion, impact
> velocity also affects how the cue joint responds during impact, which
> in turn affects how the shaft and tip move during impact.
>

This seems odd. I agree with the notion that swerve will come into play. A very polished slippery ball will swerve less,
sure.I would imagine that could account for the rather 'high' squirt of shafts across the board (to quote Ron Shepard.) I
would think that would come into play much more than joint type. But that feeling stems from personal experience hitting
balls.
Joe


--
http://www.kudraband.com


Dan White

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Apr 27, 2004, 9:10:44 AM4/27/04
to
"JoePisko" <joe...@comcast.net> wrote in message
news:408E4DEF...@comcast.net...

I'll see if I can get a better explanation next time I see him.

dwhite


Patrick Johnson

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Apr 27, 2004, 9:24:47 AM4/27/04
to
Ron:
>>... these values do not agree with

>>the data at the Platinum site.

Not by a mile.

Gregory:


> Something in their method is yielding very
> high squirt numbers across the board.

No shit. Considering that they're supposed to reflect the results for
9mm of "axis offset", and assuming that means something like 6mm of
actual "contact point offset", then the range of pivot lengths for all
the listed sticks would be 5.8 inches to 8.7 inches -- obviously not
correct. Even at 12mm of contact point offset the range of pivot
lengths is only 11.7 inches to 17.5 inches -- still too low to make sense.

I don't think we can take these numbers seriously, even for showing the
relative squirt of different shafts.

Pat Johnson
Chicago

Newsposts1

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Apr 27, 2004, 10:56:33 PM4/27/04
to
"John Barton" <inst...@instroke.com> wrote in message news:<EaKdnQ_YHsq...@centurytel.net>...

> If the Platinum billiards people are testing a LOT of different products
> using the same set of conditions and just reporting on the results then
> doesn't that show some form of impartiality?

How can the tests be considered impartial when the results are
meaningless?

> Okay, two questions, if the cues are all tested under the same conditions
> would it not be fairly safe to assume that the performance numbers would
> continue to show similar differences between cues when the variables are
> changed.

This might be a safe assumption in your opinion, but in mine it is
not. This is the whole point behind my responses.

Without showing a relationship between impact velocity and deflection,
and without demonstrating that impact velocity was above some minimum
threshold to prevent swerve, these and other similar kinds of "test
results" are garbage, crapola, meaningless, useless, misleading, etc.,
etc., etc.

> IOW, A high deflection shaft wouldn't become a low deflection one
> through more velocity would it?

Again you are missing the whole point. The question is whether or not
the shaft delivers the same amount of deflection over all impact
velocities.

Here is a proposal to consider:

What would you rather have:

a) a shaft that has very low deflection at low impact velocity, but
has medium deflection at medium impact velocity and high deflection at
high impact velocity

or

b) a shaft that has medium deflection at low and medium impact
velocities and high deflection at high impact velocity

or

c) a shaft that has high deflection at low, medium and high impact
velocities

John Barton

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Apr 27, 2004, 11:34:05 PM4/27/04
to

"Newsposts1" <stev...@3cushion.com> wrote in message
news:52c1c1b1.04042...@posting.google.com...
> "John Barton" <inst...@instroke.com> wrote in message
news:<EaKdnQ_YHsq...@centurytel.net>...
>
> > If the Platinum billiards people are testing a LOT of different products
> > using the same set of conditions and just reporting on the results then
> > doesn't that show some form of impartiality?
>
> How can the tests be considered impartial when the results are
> meaningless?

What does the meaning of the results have to do with the impartiality? I
could just as easily strap cues into a sling just to see which one goes
farthest and I would be completely impartial to the brands (unless I owned
the cues being slung) and the results would be meaningless to anyone. My
point is that the raw data collected isn't neccesarily marketing hype or
showing of partiality to any particular brand. People perform experiments
all the time without knowing whether the results will be "meaningful" or
useful now or in the future. They just want to see what happens.

>
> > Okay, two questions, if the cues are all tested under the same
conditions
> > would it not be fairly safe to assume that the performance numbers would
> > continue to show similar differences between cues when the variables are
> > changed.
>
> This might be a safe assumption in your opinion, but in mine it is
> not. This is the whole point behind my responses.
>
> Without showing a relationship between impact velocity and deflection,
> and without demonstrating that impact velocity was above some minimum
> threshold to prevent swerve, these and other similar kinds of "test
> results" are garbage, crapola, meaningless, useless, misleading, etc.,
> etc., etc.
>
> > IOW, A high deflection shaft wouldn't become a low deflection one
> > through more velocity would it?
>
> Again you are missing the whole point. The question is whether or not
> the shaft delivers the same amount of deflection over all impact
> velocities.

Why is this important? I don't disagree that it isn't but somewhere along
the line some kind of average will have to be determined to publish any kind
of results which can be used for the general public. All I see is that you
want to add more variables to the tests. Of course, the cues can be tested
infinitely with every possible combination of construction, mates, impact
velocity, offset, pivot point and so on but what is the point? You calimed
that the data presented is nothing more than marketing hype, i.e. it is
either false or somehow manipulated to favor Platinum Billiards. I
disagree. I think that they are providing data gleaned from whatever tests
they did and letting the consumer infer what he will from that data.

>
> Here is a proposal to consider:
>
> What would you rather have:
>
> a) a shaft that has very low deflection at low impact velocity, but
> has medium deflection at medium impact velocity and high deflection at
> high impact velocity
>
> or
>
> b) a shaft that has medium deflection at low and medium impact
> velocities and high deflection at high impact velocity
>
> or
>
> c) a shaft that has high deflection at low, medium and high impact
> velocities

I would rather have a shaft that "feels" good and so far no one can test for
that. What I would like to see is some tests to show the effects of various
taper/ferrule/tip/joint combinations along with "feel" opinions from a test
group of good players. Then I would be able to order a shaft by the numbers
and every shaft on every cue could get a number based on it's particular
construction. This way if I called up Mark Smith Cues and said I would like
to have a #R453 Shaft then he would know that it's a flat faced Radial pin
with a 12 inch taper, an Aegis ferrule and an Instroke 11 Layered Medium tip
:-) I would know I am getting a shaft with x-delfection at x-velocity that
I am already comfortable with.

Dial-a-Shaft(tm) There, now I said it first. Anybody does it just give me 5%
and keep me supplied with shafts. :-))

John
www.cuecaserepair.com

Newsposts1

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Apr 28, 2004, 12:24:08 AM4/28/04
to
JoePisko <joe...@comcast.net> wrote in message news:<408E50F9...@comcast.net>...

> This seems odd. I agree with the notion that swerve will come into play. A
> very polished slippery ball will swerve less,
> sure.I would imagine that could account for the rather 'high' squirt of
> shafts across the board

You are missing the point. It is not a question of more or less
swerve. It is a question of impact velocity.

Swerve comes into play when the ball is rolling, not sliding. In order
to measure deflection accurately over certain distance, the ball must
be struck with a certain minimum impact velocity such that the ball
will slide over that distance and not begin to roll.

New ball or old ball, new cloth or old cloth, it doesn't matter. All
balls struck with side spin will change from slide to roll at some
point. With respect to deflection, the key to an accurate measurement
is to provide enough impact velocity so that the ball does not change
from slide to roll over the measurement distance. To do so, keeps
swerve out of the measurement result.

IOW, when trying to accurately measure and compare a cue's deflection
characteristics on a carom table with new balls and new cloth, versus
a pool table with old balls and old cloth, different ranges of impact
velocities must be used during the measurement to prevent having the
results skewed by effects of swerve.

> I would think that would come into play much more than joint type.

IMHO, this is incorrect. The style of joint has everything to do with
how the shaft can respond during impact, which in turn affects the
motion of the tip during impact, which in turn affects the amount of
deflection.

Ron Shepard

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Apr 28, 2004, 12:35:16 AM4/28/04
to
In article <nOydnbAbZ8C...@centurytel.net>,
"John Barton" <inst...@instroke.com> wrote:

> > Again you are missing the whole point. The question is whether or not
> > the shaft delivers the same amount of deflection over all impact
> > velocities.
>
> Why is this important? I don't disagree that it isn't but somewhere along
> the line some kind of average will have to be determined to publish any kind
> of results which can be used for the general public.

Steve hasn't said this explicitly, but for several years now the
rumors have been that the Meucci ferrule design has low squirt for
soft shots and higher squirt for faster shots. This is because the
end of the ferrule wiggles, it is not firmly attached to the tenon
at the end of the tip. I have never seen data published that would
prove or disprove this rumor, so it could be negative marketing hype
from competitors. All these guys have egos, which isn't a bad
thing, but you have to be skeptical of everything you hear from
them. However, for a regular solid ferrule design, this mechanism
would not affect squirt, and it would be reasonable to expect the
same squirt at all shot speeds (at least all shot speeds short of
shattering the ferrule).

$.02 -Ron Shepard

Newsposts1

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Apr 28, 2004, 7:07:21 AM4/28/04
to
"John Barton" <inst...@instroke.com> wrote in message news:<nOydnbAbZ8C...@centurytel.net>...

> > Again you are missing the whole point. The question is whether or not
> > the shaft delivers the same amount of deflection over all impact
> > velocities.
>
> Why is this important?

Aren't the reasons obvious?

Let's say you have Cue A and Cue B.

Let's assume further that we have determined beyond a shadow of a
doubt that Cue A has low deflection at low velocity, the exact same
amount of deflection at medium velocity and the exact same amount of
deflection at high velocity.

Similarly, we have determined that Cue B also has this exact same
amount of low deflection at low velocity, but 2 to 4 times that amount
at medium velocity and 8 to 10 times that amount at high velocity.

Some obvious conclusions would have to be:
1. Cue A has a superior design, relative to Cue B.
2. Cue A is predictable and controllable across a large range of
shots, contrary to Cue B.
3. Cue A and Cue B could both easily be advertised as a "low
deflection" cues. However with Cue A, the advertiser could be
completely truthful. However with Cue B, the results and premise of
the advertisement would have to be purposely vague in order to not
have the advertiser posting a blatant lie.

Having the same deflection characteristics over the full range of
impact velocities, means that an accurate and reliable method of
compensation could be applied.

More importantly, it means that the average amateur player is probably
going to be more accurate in making shots with english with Cue A,
than he or she would be with Cue B. IOW, cue design and cue
performance alone can make a player better (all other things being
equal).

IMHO, having the same deflection characteristics over the full range
of impact velocities, is also consistent with a cue design that has
low to no deflection. IOW, I don't think you will ever see a cue with
consistent, but high, amounts of deflection.

> I think that they are providing data gleaned from whatever tests
> they did and letting the consumer infer what he will from that data.

Yeah .... sure .... but are they telling the consumer the whole story?
IMHO, no they are not. They are telling the consumer what they think
will make the consumer buy one or more of their products.

> I would rather have a shaft that "feels" good and so far no one can test for
> that. What I would like to see is some tests to show the effects of various
> taper/ferrule/tip/joint combinations along with "feel" opinions from a test
> group of good players.

This may be all well and good, but honestly what would you hope to get
from this other than a verbal advertisement? How many good players got
to be good players because they worked hard to become experts with the
equipment of the sport, as opposed to practicing and competing? IMHO,
very few if any. They became good players because they did repetitive
activities over and over until they became proficient at it, not
because they studied and became experts with the equipment.

Your other point about ordering a cue with precise known
specifications is a good one. But how realistic do you think it is?

How many cues today are sold because of name recognition and perceived
"reputation" alone? Probably somewhere between 75%-100%. How many cues
are sold today because they can be built to a precise set of
performance characteristics. Probably zero.

So again, your point is a good one, but not very likely because it is
not something that most manufacturers want to see. Their money is in
sales because of name recognition and perceived reputation.

Newsposts1

unread,
Apr 28, 2004, 7:31:27 AM4/28/04
to
Ron Shepard <ron-s...@NOSPAM.comcast.net> wrote in message news:<ron-shepard-D0AF...@comcast.ash.giganews.com>...

> ..... for several years now the

> rumors have been that the Meucci ferrule design has low squirt for
> soft shots and higher squirt for faster shots. This is because the
> end of the ferrule wiggles, it is not firmly attached to the tenon
> at the end of the tip.

Once again Ron, you manage to dance around the real issue without
really stepping into it.

Your mention of this thing with the Meucci ferrule is in all honesty
the first that I have ever heard about it.

If what you say is true, then it makes all the sense in the world. If
there is not a strong mechanical connection, then the motion at the
tip would very likely be inconsistent and unpredictable especially as
imact velocity gets larger and larger.

Yet you won't go one step further and apply the same principle to the
joint.

If a cue's joint is strong enough and stiff enough to hold the joint
together in the same way over the full range of expected impact
velocities, then wouldn't it be logical to assume that the deflection
should be consistent (and probably quite low as well)?

On the other hand, if a joint isn't strong enough to hold the joint
together the same way during all ranges of impacts, then wouldn't this
be just like the case that you mention. IOW, as impact velocity get's
higher and higher the stability of the joint gets lower and lower,
meaning the tip has a greater likelihood of moving in a uncontrolled
manner (i.e., greater and/or unpredictable deflection).

Confucious say "he who walk fence end up with chopped nuts." Either
all joints are the same or all joints are not the same, relative to
their effect upon cue performance. There really isn't any middle
ground on the issue.

I don't think there is anyone out there who would agree that all
joints are the same. Yet no one beside me and a handful of others
wants to look why all joints aren't the same. In light of this and
other discussions, doesn't it seem reasonable to assume that their is
a relationship between joint design, impact velocity and deflection?

(For purposes of this thread, I omitted shaft design and some other
things, but these are important as well.)

{We could even take this concept of mechanical connections one steps
further. Everyone says they prefer glued-on tips versus threaded
screw-on tips, but no one looks at the why. The why is the glued-on
tips provide a more secure, consistent and stable mechanical
connection than the screw-on tips. IOW, the more secure mechanical
connection provides better performance.

So now, this thread has talked about a logical basis for relationship
between stable mechanical connections and deflection for both the tip
connection to the shaft and the ferrule connection to the shaft. Isn't
it time now to accept the reality that butt connection to the shaft is
also important, and start looking at exactly how important?}

JoePisko

unread,
Apr 28, 2004, 9:07:33 AM4/28/04
to

Newsposts1 wrote:

>
> I don't think there is anyone out there who would agree that all
> joints are the same. Yet no one beside me and a handful of others
> wants to look why all joints aren't the same. In light of this and
> other discussions, doesn't it seem reasonable to assume that their is
> a relationship between joint design, impact velocity and deflection?
>

Hmmm, all joins the same? No. Join design not affecting the cue balls path regardless of where you hit the ball and how hard, IMHO
yes. Why do I believe this? Personal experimentation. After radically altering the stiffness of the cue's joint (by placing a rubber
washer between the shaft and butt) there seemed to be absolutely no difference in deflection (squirt, but deflections sounds so much
more scientific like) or spin. This was not just the case for my own cue, but all the other cues I tried (I am lucky enough to have a
whole wall full at my disposal.) I was quite surprised. I was so certain that it would make some sort of difference that I tried this
for a whole afternoon. But really the cues did not change at all. Give it a try sometime.
Joe


Platinum Billiards

unread,
Apr 28, 2004, 9:12:24 AM4/28/04
to
> In article <nOydnbAbZ8C...@centurytel.net>,
> "John Barton" <inst...@instroke.com> wrote:
>
> > > Again you are missing the whole point. The question is whether or not
> > > the shaft delivers the same amount of deflection over all impact
> > > velocities.
> >
> > Why is this important? I don't disagree that it isn't but somewhere along
> > the line some kind of average will have to be determined to publish any kind
> > of results which can be used for the general public.
>
> However, for a regular solid ferrule design, this mechanism
> would not affect squirt, and it would be reasonable to expect the
> same squirt at all shot speeds (at least all shot speeds short of
> shattering the ferrule).
>
> $.02 -Ron Shepard
We have done a fair amount of this speed vs squirt testing and while
this is a very important question, thus far we have only seen slight
variation from the "flat line" that Ron has predicted. But these
slight variations deserve more scrutiny, as do the curves of squirt vs
offset. The test surface is very low friction to eliminate the swerve
factor, though we have shot off of "pads" of various types of cloth,
clean and dirty, none of which has produced significant change in
squirt or cb speed.

Patrick Johnson

unread,
Apr 28, 2004, 9:37:40 AM4/28/04
to
Steve:
> ... It is not a question of more or less

> swerve. It is a question of impact velocity.

> ... different ranges of impact


> velocities must be used during the measurement to prevent having the
> results skewed by effects of swerve.

Sounds like a question of more or less swerve to me...

> Swerve comes into play when the ball is rolling, not sliding.

Swerve happens ONLY while the ball is sliding - most of it happens at
the end of the slide, but none of it happens after the ball is rolling.
Hitting harder doesn't eliminate swerve entirely, it just reduces it
to an insignificant amount.

> ... provide enough impact velocity so that the ball does not change


> from slide to roll over the measurement distance. To do so, keeps
> swerve out of the measurement result.

Not quite. You have to hit hard enough to only get the minimal very
first part of the swerve.

> ... The style of joint has everything to do with


> how the shaft can respond during impact, which in turn affects the
> motion of the tip during impact, which in turn affects the amount of
> deflection.

Bullshit. Prove it. You've been saying the same nonsense for years and
have never offered anything but noise about it. Do something useful for
a change.

Pat Johnson
Chicago

Gregory

unread,
Apr 28, 2004, 10:08:23 AM4/28/04
to
Newsposts1 wrote

> So now, this thread has talked about a logical basis for relationship
> between stable mechanical connections and deflection for both the tip
> connection to the shaft and the ferrule connection to the shaft. Isn't
> it time now to accept the reality that butt connection to the shaft is
> also important, and start looking at exactly how important?}

Do you believe that the joints at the ends of the handle affect squirt?
How about the bumper?


Newsposts1

unread,
Apr 28, 2004, 7:32:02 PM4/28/04
to
Patrick Johnson <patrick...@comcast.net> wrote in message news:<108vct3...@news.supernews.com>...

> > Swerve comes into play when the ball is rolling, not sliding.
>
> Swerve happens ONLY while the ball is sliding - most of it happens at
> the end of the slide, but none of it happens after the ball is rolling.

This is completely incorrect. Swerve is caused by rolling friction,
not sliding friction.

> > ... The style of joint has everything to do with
> > how the shaft can respond during impact, which in turn affects the
> > motion of the tip during impact, which in turn affects the amount of
> > deflection.
>
> Bullshit. Prove it. You've been saying the same nonsense for years and
> have never offered anything but noise about it.

Everytime I try to start with an explanation, you and others either
close your minds or incorrectly interpret what I'm saying.

Either all joints are the same or they are all not the same. There is
no in between. I think everyone agrees all joints are not the same. So
now the question is why aren't they all the same? I've offered on
explanation that you refuse to consider. That is your problem, not
mine.

Newsposts1

unread,
Apr 28, 2004, 7:36:57 PM4/28/04
to
"Gregory" <greye...@bellsouth.net> wrote in message news:<5OOjc.35776$oN1....@bignews5.bellsouth.net>...

> Do you believe that the joints at the ends of the handle affect squirt?

The cue's stiffness is directly related to the quality and type of
handle joint. So it would seem possible that there is some impact to
deflection. It depends on the design of the rest of the cue, including
the butt/shaft joint.

> How about the bumper?

Is this a serious question?

Newsposts1

unread,
Apr 28, 2004, 7:41:11 PM4/28/04
to
st...@platinumbilliards.com (Platinum Billiards) wrote in message news:<80ba6fc.04042...@posting.google.com>...

> We have done a fair amount of this speed vs squirt testing and while


> this is a very important question, thus far we have only seen slight
> variation from the "flat line" that Ron has predicted. But these
> slight variations deserve more scrutiny, as do the curves of squirt vs
> offset.

Any data that you might care to share?

Slight variation could mean a lot of different things. While the
numbers are important, the more important question is whether or not
"slight variation" is large enough to cause a missed shot or missed
position.

Newsposts1

unread,
Apr 28, 2004, 7:43:28 PM4/28/04
to
JoePisko <joe...@comcast.net> wrote in message news:<408FD424...@comcast.net>...

> Hmmm, all joins the same? No.

Why are they all not the same?

> Join design not affecting the cue balls path regardless of where you hit the
> ball and how hard, IMHO yes. Why do I believe this? Personal experimentation.

How did you test? What were your results? Do you have numbers to share?

Newsposts1

unread,
Apr 28, 2004, 7:46:17 PM4/28/04
to
Patrick Johnson <patrick...@comcast.net> wrote in message news:<108vct3...@news.supernews.com>...

> > Swerve comes into play when the ball is rolling, not sliding.


>
> Swerve happens ONLY while the ball is sliding - most of it happens at
> the end of the slide, but none of it happens after the ball is rolling.

One other thing .... since you blew it on the swerve thing .....

What exactly happens when the cue ball changes from a sliding state to
a rolling state?

Patrick Johnson

unread,
Apr 28, 2004, 11:50:22 PM4/28/04
to
Newsposts1 wrote:

> What exactly happens when the cue ball changes from a sliding state to
> a rolling state?

If you mean when it no longer has any sliding friction, then the answer
is it rolls, without changing direction, until it hits something or stops.

What do you think a rolling ball with no sliding friction does?

Pat Johnson
Chicago

Ron Shepard

unread,
Apr 29, 2004, 1:34:31 AM4/29/04
to
In article <52c1c1b1.04042...@posting.google.com>,
stev...@3cushion.com (Newsposts1) wrote:

> > Swerve happens ONLY while the ball is sliding - most of it happens at
> > the end of the slide, but none of it happens after the ball is rolling.
>
> One other thing .... since you blew it on the swerve thing .....

I think Pat is right on this on. Swerve, semi-masse, masse, or the
ball rebounding from a collision with a cushion or another ball --
all these involve the cue ball sliding in a parabolic path on the
cloth. Once the cue ball stops sliding and starts rolling, it rolls
in a straight line (assuming a level table and a uniform round ball).

Of course, a parabola can be a straight line too, but those aren't
the ones that result in swerve.



> What exactly happens when the cue ball changes from a sliding state to
> a rolling state?

It changes from a curved path to a straight path.

The acceleration changes from sliding friction to rolling resistance.

The path is continuous, and the first derivative is continuous, but
the second derivative is discontinuous at the point of change.

$.02 -Ron Shepard

Ron Shepard

unread,
Apr 29, 2004, 1:43:23 AM4/29/04
to

> Your mention of this thing with the Meucci ferrule is in all honesty
> the first that I have ever heard about it.

I first read about this here in RSB. Since then, I have heard
several other people talk about it.



> If what you say is true, then it makes all the sense in the world. If
> there is not a strong mechanical connection, then the motion at the
> tip would very likely be inconsistent and unpredictable especially as
> imact velocity gets larger and larger.
>
> Yet you won't go one step further and apply the same principle to the
> joint.

As you know by now, the joint is too far away. We went through this
a couple of months ago, remember? The sideways vibrational motion
only affects the last few inches of the shaft, so that is the only
part of the cue that contributes to the inertia (the resistance to
sideways motion) that determines squirt.

$.02 -Ron Shepard

Mike Page

unread,
Apr 29, 2004, 10:40:08 AM4/29/04
to

Neither were serious questions. lol

Mike Page

unread,
Apr 29, 2004, 10:47:12 AM4/29/04
to

> Patrick Johnson <patrick...@comcast.net> wrote in message
> news:<108vct3...@news.supernews.com>...
>
> > > Swerve comes into play when the ball is rolling, not sliding.
> >
> > Swerve happens ONLY while the ball is sliding - most of it happens at
> > the end of the slide, but none of it happens after the ball is rolling.
>
> This is completely incorrect. Swerve is caused by rolling friction,
> not sliding friction.

nonsense.

Patrick Johnson

unread,
Apr 29, 2004, 11:06:32 AM4/29/04
to
Newsposts1 wrote:

> This is completely incorrect. Swerve is caused by rolling friction,
> not sliding friction.

Is this the kind of statement you want everybody to take more seriously?

> Either all joints are the same or they are all not the same. There is
> no in between. I think everyone agrees all joints are not the same. So
> now the question is why aren't they all the same?

The question is how can this affect squirt. Ron has given a simple and
straightforward answer to that (it can't, because transverse waves are
too slow to get to the joint and back while the tip's on the ball).
Answer this simple, on-point statement with a simple, on-point rebuttal
and you'll get the fair hearing you say you want. Answer with your
usual question-dodging tapdance and you'll get laughed off the stage as
usual.

Pat Johnson
Chicago

Gregory

unread,
Apr 29, 2004, 11:26:23 AM4/29/04
to
Newsposts1 wrote
> Gregory wrote

> > Do you believe that the joints at the ends of the handle affect
squirt?
>
> The cue's stiffness is directly related to the quality and type of
> handle joint. So it would seem possible that there is some impact to
> deflection. It depends on the design of the rest of the cue, including
> the butt/shaft joint.
>
> > How about the bumper?
>
> Is this a serious question?

Yes. I'm trying to find out how far back in a cue you believe a
joint/change in material will affect squirt. The butt/bumper interface
is a joint/ change in material.


Newsposts1

unread,
Apr 29, 2004, 8:41:55 PM4/29/04
to
"Gregory" <greye...@bellsouth.net> wrote in message news:<%49kc.67066$Yw5....@bignews4.bellsouth.net>...

> Yes. I'm trying to find out how far back in a cue you believe a
> joint/change in material will affect squirt. The butt/bumper interface
> is a joint/ change in material.

The only concern is for parts of the cue that are under load during
impact. The bumper is not loaded, so it is not worth consideration.

Newsposts1

unread,
Apr 29, 2004, 9:03:56 PM4/29/04
to
Patrick Johnson <Patrick.Jo...@THIScomcast.net> wrote in message news:<10926kd...@news.supernews.com>...

> Answer this simple, on-point statement with a simple, on-point rebuttal
> and you'll get the fair hearing you say you want.

I couldn't give a flying f**k about getting a "fair hearing" from nits
like you Pat. I have absolutely zero urgency that I have to prove
something to you in order for it to be valid.

You have your own set of beliefs firmly ingrained in your head and
there is nothing anyone can do about it. Frankly, your opinions about
the mechanics of billiards are meaningless to me, because you don't
have the ability or willingness to try and comprehend anything outside
of this narrow set of beliefs.

> The question is how can this affect squirt. Ron has given a simple and
> straightforward answer to that (it can't, because transverse waves are
> too slow to get to the joint and back while the tip's on the ball).

I've already answered this question about a million times, but you
never seem to want to listen to the answer.

The types of vibrations that can propagate in a cue during impact are
determined by a cue's stiffness under load. A cue's stiffness under
load is determined almost exclusively by taper, construction materials
and joint design. Ergo, the types of vibrations that can propagate in
a cue during impact are determined by taper, construction materials
and joint design. These are undisputable facts.

Is that a small enough bit of information to be accommodated by your
limited cranial capacity?????

Platinum Billiards

unread,
Apr 29, 2004, 11:31:19 PM4/29/04
to
> Slight variation could mean a lot of different things. While the
> numbers are important, the more important question is whether or not
> "slight variation" is large enough to cause a missed shot or missed
> position.

Really accurate testing of speed vs squirt is a tricky business - it
takes a great many shots and the tip takes a beating, and squirt is
very sensitive to the shape of the tip. What I have seen so far is
that, for a pretty good variety of shafts, squirt tends to increase
with speed at the rate of .2% to .3% per mph, over the range of 9mph
to 21mph.
--Steve

Newsposts1

unread,
Apr 30, 2004, 2:13:57 AM4/30/04
to
Ron Shepard <ron-s...@NOSPAM.comcast.net> wrote in message news:<ron-shepard-088F...@comcast.ash.giganews.com>...

As you know by now, the joint is too far away.

So all joints are the same ? The joint has no effect on cue
performance ?

> We went through this
> a couple of months ago, remember? The sideways vibrational motion
> only affects the last few inches of the shaft, so that is the only
> part of the cue that contributes to the inertia (the resistance to
> sideways motion) that determines squirt.

What we went through was conjecture on the above paragraph on the part
of you and Bob. I don't happen to subscribe to the notion.

What neither of you and Pat and others don't realize is that the joint
is a factor is determining how, when and where this vibration occurs?

The cue is an integrated structure, of which several components
contribute to vibration, deflection, etc.

For some reason, you continue to believe that all the secrets of the
cue are in the first couple of inches. This is ludicrous.

Newsposts1

unread,
Apr 30, 2004, 2:39:39 AM4/30/04
to
Ron Shepard <ron-s...@NOSPAM.comcast.net> wrote in message news:<ron-shepard-56CD...@comcast.ash.giganews.com>...

> I think Pat is right on this on.

I find it scary when an intelligent person like yourself is in
agreement with Pat about anything.

> Swerve, semi-masse, masse, or the
> ball rebounding from a collision with a cushion or another ball --
> all these involve the cue ball sliding in a parabolic path on the
> cloth.

However, we are not talking about collisions with cushions and balls
when discussing deflection. We are talking about movement off the tip
of the cue.

In order to create a parabolic curve off the tip of the cue, the cue
must be jacked up way above the horizontal.

In order to measure deflection accurately, the cue should be parallel
with the bed of the table and contacting the cue ball somewhere on the
equator.

> Once the cue ball stops sliding and starts rolling, it rolls
> in a straight line (assuming a level table and a uniform round ball).

This is not correct. When a ball is rolling with a sidespin component,
there is a frictional force which acts in such a manner as to cause
the ball to curve slightly in the direction of the spin.

Byrne and many other writers talk about it, and your paper discusses
it a bit as well. This is what I am referring to when I mentioned
swerve, in the context of altering a deflection measurement,
especially one that is done over most of a table length in distance.


> > What exactly happens when the cue ball changes from a sliding state to
> > a rolling state?
>
> It changes from a curved path to a straight path.
>
> The acceleration changes from sliding friction to rolling resistance.

The point I was trying to get to was the fact that the instant the
ball changes from a sliding condition to a rolling condition, there is
a significant change in the position of the axis of rotation.

IOW, the contact point between tip and ball does not solely determine
the position of the axis of rotation. It is the combination of the tip
force on the ball initially, followed by the frictional force between
ball and table, that determines the position of the axis of rotation.

Mike Page

unread,
Apr 30, 2004, 9:55:01 AM4/30/04
to

> Ron Shepard <ron-s...@NOSPAM.comcast.net> wrote in message
> news:<ron-shepard-56CD...@comcast.ash.giganews.com>...
>

[...]

> > Once the cue ball stops sliding and starts rolling, it rolls
> > in a straight line (assuming a level table and a uniform round ball).
>
> This is not correct. When a ball is rolling with a sidespin component,
> there is a frictional force which acts in such a manner as to cause
> the ball to curve slightly in the direction of the spin.
>
> Byrne and many other writers talk about it, and your paper discusses

> it a bit as well. [...]

This is interesting Steve. Do you have a more specific reference to
where you think Byrne or Shepard support this?

Patrick Johnson

unread,
Apr 30, 2004, 10:09:58 AM4/30/04
to
Platinum Billiards wrote:

> ... squirt is


> very sensitive to the shape of the tip. What I have seen so far is
> that, for a pretty good variety of shafts, squirt tends to increase
> with speed at the rate of .2% to .3% per mph, over the range of 9mph
> to 21mph.

Which is a total range of 2%-3%. I don't think this is significant.

But I don't know whether to take your numbers seriously, given the
strange squirt numbers you show. Can you explain them? Do you really
believe the range of squirt among the shafts you measured only differs
by 50% despite other measurements that say it differs several times as much?

Pat Johnson
Chicago

Ron Shepard

unread,
Apr 30, 2004, 12:19:14 PM4/30/04
to

> Ron Shepard <ron-s...@NOSPAM.comcast.net> wrote in message
> news:<ron-shepard-088F...@comcast.ash.giganews.com>...
>
> As you know by now, the joint is too far away.
>
> So all joints are the same ? The joint has no effect on cue
> performance ?

That is not what I said, it is not what I intended to say, and it is
not what I believe. I think the joint has no significant effect on
squirt. You keep trying to change the word "squirt" into
"performance" for some reason. You should know how I feel by know
about the importance of joint types, I've posted it dozens of times
here in RSB.



> > We went through this
> > a couple of months ago, remember? The sideways vibrational motion
> > only affects the last few inches of the shaft, so that is the only
> > part of the cue that contributes to the inertia (the resistance to
> > sideways motion) that determines squirt.
>
> What we went through was conjecture on the above paragraph on the part
> of you and Bob. I don't happen to subscribe to the notion.

You failed to support your notion with any kind of argument. I
think Bob's argument was basically correct (relating the distance
between the nodes and the vibrational frequency to the wave speed).



> What neither of you and Pat and others don't realize is that the joint
> is a factor is determining how, when and where this vibration occurs?

I realize that and I agree with it. I expect everyone else does too.



> The cue is an integrated structure, of which several components
> contribute to vibration, deflection, etc.

Yes, but you seem to think that all components affect all features
equally. They don't. In particular, I think that joint type has no
significant affect on squirt. I think that joint type is
significant for other features, but not for squirt.



> For some reason, you continue to believe that all the secrets of the
> cue are in the first couple of inches. This is ludicrous.

I don't know if "ludicrous" would be correct for such a claim, but
it is irrelevant in any case because I don't think that *all*
secrets of the cue are in the first couple of inches. I do think
that the first few inches of the shaft are the most important
characteristic that determines squirt.

You are trying to set up a straw man argument so you can knock it
down and celebrate victory. No one here is claiming any of the
things you say. You can certainly disagree with what other's here
say, but it would be more productive if you would argue against what
we actually say, not argue against these fictional straw man
arguments.

$.02 -Ron Shepard

Ron Shepard

unread,
Apr 30, 2004, 12:47:40 PM4/30/04
to

> > Swerve, semi-masse, masse, or the
> > ball rebounding from a collision with a cushion or another ball --
> > all these involve the cue ball sliding in a parabolic path on the
> > cloth.
>
> However, we are not talking about collisions with cushions and balls
> when discussing deflection. We are talking about movement off the tip
> of the cue.

My point is that all of these curved paths are caused by the same
thing.



> In order to create a parabolic curve off the tip of the cue, the cue
> must be jacked up way above the horizontal.

No, any cue elevation at all results in a curved parabolic path. A
level cue, even with sidespin, does not result in a curved path.
That is why I made the comment before that a straight line is a
special case of a parabola. A sliding ball always moves along a
parabolic path, and usually that path is curved, but it is possible
also for a ball to slide in a straight line which is a special case
of the parabolic slide.



> In order to measure deflection accurately, the cue should be parallel
> with the bed of the table and contacting the cue ball somewhere on the
> equator.

It is possible to shoot with enough speed so that the curve of the
parabola is very small, less than a fraction of a millimeter for
example, while the squirt is in the 10 to 100 millimeters range.
With such a setup, the swerve error in the squirt measurement would
be relatively small, say 1% or less.


> > Once the cue ball stops sliding and starts rolling, it rolls
> > in a straight line (assuming a level table and a uniform round ball).
>
> This is not correct. When a ball is rolling with a sidespin component,
> there is a frictional force which acts in such a manner as to cause
> the ball to curve slightly in the direction of the spin.
>
> Byrne and many other writers talk about it, and your paper discusses
> it a bit as well.

Yes we do, but you must be thinking of something else. Byrne gives
a simple experiment to disprove your hypothesis. Spin a ball with
your fingers so that it is spinning in place on the table. Take
another ball and bump it from the side. Observe the path that the
spinning ball takes. If the spin causes the ball to curve, which is
your hypothesis, then the ball would roll along a curved path,
perhaps even tracing out a circle on the table cloth. If the
sidespin does not cause a curve, then the ball will roll in a
straight line. This is a simple experiment that anyone can do to
find the correct answer to this question.


> This is what I am referring to when I mentioned
> swerve, in the context of altering a deflection measurement,
> especially one that is done over most of a table length in distance.

I understand this, but I think you are getting the sliding and the
rolling parts of the path confused. The swerve occurs during the
sliding part of the ball path, not during the rolling part of the
path. Once the ball starts rolling it rolls in a straight line.
That straight line is not along the original stick direction, it is
usually at some angle relative to the stick. Therefore, the rolling
distance (i.e. the shot distance) does affect how much aiming
compensation is required on swerve shots.



> > > What exactly happens when the cue ball changes from a sliding state to
> > > a rolling state?
> >
> > It changes from a curved path to a straight path.
> >
> > The acceleration changes from sliding friction to rolling resistance.
>
> The point I was trying to get to was the fact that the instant the
> ball changes from a sliding condition to a rolling condition, there is
> a significant change in the position of the axis of rotation.

I don't think this is true. At the moment before the ball stops
sliding, the axis of rotation is somewhere in the plane
perpendicular to the ball velocity with an infinitesimal component
along that velocity direction. At the next instant, it is only that
infinitesimal component that changes, becoming zero. BTW, the
horizontal component of the spin axis is fixed according to the ball
velocity, V=rw, and the vertical component is free to take on any
value, positive or negative. This means that, viewing the ball from
behind, the spin axis is somewhere in the 6:00 to 12:00 range on a
clock face. the 9:00 direction would correspond to no sidespin, the
10:00 direction would correspond to right sidespin, and the 8:00
direction would correspond to left sidespin.



> IOW, the contact point between tip and ball does not solely determine
> the position of the axis of rotation. It is the combination of the tip
> force on the ball initially, followed by the frictional force between
> ball and table, that determines the position of the axis of rotation.

This is correct.

$.02 -Ron Shepard

Ron Shepard

unread,
Apr 30, 2004, 12:53:27 PM4/30/04
to
In article <1094nmd...@news.supernews.com>,
Patrick Johnson <Patrick.Jo...@THIScomcast.net> wrote:

> Do you really
> believe the range of squirt among the shafts you measured only differs
> by 50% despite other measurements that say it differs several times as much?

I think when Steve Titus does the aim-and-pivot measurement, he gets
the same value as the rest of us. I think there is some
experimental detail that is causing the confusion, and when we
finally figure it out, it will be obvious.

Sort of like how your lost keys are always in the last place you
look.

$.02 -Ron Shepard

Patrick Johnson

unread,
Apr 30, 2004, 1:06:03 PM4/30/04
to
Ron Shepard wrote:

> ... your lost keys are always in the last place you look.

If you know that, why not just tell me where they are?

(Some friend...)
Pat Johnson
Chicago

-jeff

unread,
Apr 30, 2004, 3:02:59 PM4/30/04
to
stev...@3cushion.com (Newsposts1) wrote:
> Ron Shepard wrote...

>
> As you know by now, the joint is too far away.
>
> So all joints are the same ? The joint has no effect on cue
> performance ?
>
> > We went through this
> > a couple of months ago, remember? The sideways vibrational motion
> > only affects the last few inches of the shaft, so that is the only
> > part of the cue that contributes to the inertia (the resistance to
> > sideways motion) that determines squirt.
>
> What we went through was conjecture on the above paragraph on the part
> of you and Bob. I don't happen to subscribe to the notion.

Well, I'm pretty sure that it was proven that the sideways vibrational
motion can only make it part way down the shaft before the ball leaves
the tip. Whether this motion is the only thing that contributes to
squirt may be conjecture.



> What neither of you and Pat and others don't realize is that the joint
> is a factor is determining how, when and where this vibration occurs?

If the overall performance of a cue is dependent on the axial
vibration of the shaft, then it seems pretty obvious that the joint
would have an effect. There is enough time for the vibrations to
travel from the tip to the joint about 3 times if the numbers I looked
up for maple are correct.

> The cue is an integrated structure, of which several components
> contribute to vibration, deflection, etc.
>
> For some reason, you continue to believe that all the secrets of the
> cue are in the first couple of inches. This is ludicrous.

It may not be all the secrets, just the secret of squirt. If it was
all about the shaft then a 314 shaft on a Lambros would play identical
to a 314 on Layani which would be identical to a 314 on a Predator
which....

I don't think anybody would say that is the case given the occasional
posts about how much better a 314 shaft feels on a different butt
(could be taper, I don't know). Somebody with way more cue
experience than I have would have to comment on this tho.

Can somebody with far more vibration analysis experience explain how
vibrations propogate in a material like wood when the initial impulse
is not purely with or across the grain? Can it just be seperated into
components like vectors?

-jeff

John Barton

unread,
Apr 30, 2004, 3:41:58 PM4/30/04
to
Actually, my personal experience is that a 314 shaft on various cues feels
about the same. The glaring difference is balance and weight.

I think that the "hit" and "feel" of a cue is a product of all it's
components but that most of it is in the shaft. I have put my JossWest
shaft on a pretty crappy Taiwan butt and the hit was almost identical. The
difference was in how the two cues felt. The JossWest felt like a fine
instrument in heft and swing, The Taiwan/Joss West Shaft felt a little weird
in the swing but the cueball control was the same, the deflection was the
same.

I further believe, aside from glaring differences in performance as in a
rubber hose vs. and iron pipe, that in cues the auditory feedback is a major
factor in perception of how "good" a cue hits and feels. Thus a high
deflection cue can be "good" if the sound is acceptable to the shooter and
make him feel comfortable using it.

I believe that if one were to be able to create a half inch rod with a grip
size that is comfortable to the hand and balanced comfortably that this rod
could be mated to any number of shafts to produce a "hit" that might be
similar to any name brand cue you could mention. In a blind test this would
possibly produce the results I hypothesize.

Until Dial-a-Shaft(tm) comes along the hit, feel and performance will
continue to be a holistic marriage between personal taste, skill level and
cue construction.

John

"-jeff" <mun...@yahoo.com> wrote in message
news:67ea4f69.04043...@posting.google.com...

John W. Pierce

unread,
Apr 30, 2004, 3:45:44 PM4/30/04
to
"Patrick Johnson" <Patrick.Jo...@THIScomcast.net> wrote

>
> But I don't know whether to take your numbers seriously, given the
> strange squirt numbers you show. Can you explain them?

What they say on the web page is:

"The amount of deflection is measured on a recording device 50" away,
which is exactly the distance
between the foot string and the spot on a 4 ˝ x 9 pool table."

And in a post here (I think) one of the Platinum people (I think) said that
they used a very low friction surface for the test to avoid to the degree
possible contaminating the squirt values with the swerve effect. Sort of
like when I taped visqueen (the plastic sheeting, not the rock group) to my
table to try the same sort of tests.

Platinum's web page gives the (raw, I think) results in "millimetres per 50
inches of cueball travel". I take this to mean that they aim the cue
parallel to a 50 inch line drawn down the middle of the table, using N
millimeters of english, and that when the cue ball reaches the far end of
the line, it is M millimetres to the left/right of the line. If that is the
case, then their numbers give (very roughly) squirt angles between about 1.5
degrees and 2.7 degrees (I just interpolated from table values in my head,
so it's possible I blew it). Translated to the 75 inch shot length I used,
these give "cue ball end-of-travel offset distances" of about 2 inches to
about 3 1/2 inches. This is somewhat less than what I'd have expected, but
not really unreasonable (i.e., this corresponds fairly well to what I think
I got in my own testing). I used maximum english, whereas they use 6mm and
12mm and then combine the results, and I think that could easily account for
the differences.

-- John W. Pierce, Chem & Biochem, UC San Diego
j...@ucsd.edu


Stephen

unread,
Apr 30, 2004, 4:07:56 PM4/30/04
to
John Barton wrote:

> I have put my JossWest
> shaft on a pretty crappy Taiwan butt and the hit was almost identical. The
> difference was in how the two cues felt. The JossWest felt like a fine
> instrument in heft and swing, The Taiwan/Joss West Shaft felt a little weird
> in the swing but the cueball control was the same, the deflection was the
> same.

Were the points equally sharp? :)

Patrick Johnson

unread,
Apr 30, 2004, 4:10:55 PM4/30/04
to
Me to Platinum:

>>But I don't know whether to take your numbers seriously, given the
>>strange squirt numbers you show. Can you explain them?

John to me:
> [how Platinum measured squirt]

Yeah, I got all this from the description. My question is how do they
explain the unreasonable numbers?

> ... This is somewhat less than what I'd have expected, but


> not really unreasonable (i.e., this corresponds fairly well to what I think
> I got in my own testing).

I don't know how to translate your "cue ball end-of-travel offset
distances", but I do know that the measurements listed on the Platinum
website for Predator shafts indicate a pivot length of about 9 inches,
and that's ridiculous. On top of that, the pivot length for the highest
squirt cue is only 3 inches shorter, which may be accurate for that cue,
but is way too short a range.

I don't see how those numbers can make sense.

Pat Johnson
Chicago

lfigueroa

unread,
Apr 30, 2004, 5:36:06 PM4/30/04
to
JB says

> I further believe, aside from glaring differences in performance as in a
> rubber hose vs. and iron pipe, that in cues the auditory feedback is a
major
> factor in perception of how "good" a cue hits and feels.

I wonder if anyone has done any tests with earplugs? How the lack of an
audible "cue" changes the perception of hit.... what about the guys that
play with earphones on... what about when the juke box is turned up loud...
ok, just wondering...

Lou Figueroa

"John Barton" <inst...@instroke.com> wrote in message
news:JMOdnawbbKq...@centurytel.net...

JoePisko

unread,
Apr 30, 2004, 7:04:03 PM4/30/04
to

John Barton wrote:

>
> I further believe, aside from glaring differences in performance as in a
> rubber hose vs. and iron pipe, that in cues the auditory feedback is a major
> factor in perception of how "good" a cue hits and feels. Thus a high
> deflection cue can be "good" if the sound is acceptable to the shooter and
> make him feel comfortable using it.
>

Funny, I have been thinking this is the explanation for 'hit' quality for a
while now as well.
Joe


--
http://www.kudraband.com


Newsposts1

unread,
Apr 30, 2004, 7:58:42 PM4/30/04