dr Dave, any experiments with different cue balls?
- Thread starter DTL
- Start date
I can hardly tell the difference. I just weighed three cue balls, Measles- Red circle and blue circle. The measles is the one I play with the most and it out weighs the red circle by 7 grams and the blue circle by 6 grams.
Measles - 167 grams
Blue circle -161 grams
Red circle - 160 grams
The measles has the most miles on it followed by the red circle and then the blue circle.
Cuebuddy can't tell the diff between expensive cues and cheap cues either. But he can tell the diff between Gold crowns and Diamonds:grin:
I can tell you FOR A FACT that different cue balls jump differently. To the point where even with a jump cue you will really strugle with some of them. I had a lot of cue balls and I noticed this one day that one was really hard to jump with. So I marked them all and measured how easy or hard they were to jump with and the range went from super easy to really hard. The worst was a magnetic cue ball. I used to have a list written down but it's been gone for 10 years.
I am sure if someone were to do a controlled test they would find that some cue ball have clear performance differences.
I am sure if someone were to do a controlled test they would find that some cue ball have clear performance differences.
I'm not Dr. Dave, but I did stay at a Holday Inn Express last night!
Are you asking "is it my imagination"? If so, no, I'm sure there are some differences.
Though it's funny, your complaints are exactly what I hear people say about the measles ball.
A more useful question is "ok, they're different. How do I handle that?" I mean, realistically all you can do is accept the conditions or go somewhere else. Or buy your own cue ball and carry it everywhere... I know a few guys who do that.
To me, it's just not useful to obsess over subtle little things like this. I mean, if you play in a different pool hall, the cloth will be different right? A little faster or slower? And you adapt. It's the same thing with a different cue ball. You might blow your position once or twice early in the evening, but after an hour you should be fine. Make your best guess on speed and try to avoid field goal position shots.
Are you asking "is it my imagination"? If so, no, I'm sure there are some differences.
Though it's funny, your complaints are exactly what I hear people say about the measles ball.
A more useful question is "ok, they're different. How do I handle that?" I mean, realistically all you can do is accept the conditions or go somewhere else. Or buy your own cue ball and carry it everywhere... I know a few guys who do that.
To me, it's just not useful to obsess over subtle little things like this. I mean, if you play in a different pool hall, the cloth will be different right? A little faster or slower? And you adapt. It's the same thing with a different cue ball. You might blow your position once or twice early in the evening, but after an hour you should be fine. Make your best guess on speed and try to avoid field goal position shots.
Don't know about pool, but Amamith produces a snooker set that is matched within one gram, and the regular balls sets are, purportedly, within 3.
http://www.saluc.com/html/billiard/index.php?idlien=42
http://www.saluc.com/html/billiard/index.php?idlien=42
There are two common factors that will change how the cue ball works.
The first is the surface. To see the extremes, don't bother to clean the cue ball for a week or two. Try some draw and spin shots. Then clean it with a ball polish such as Aramith's or Chem-Pak and apply a hard wax or a little silicone spray like Armor All. (I just looked at the current range of AA products and I guess what you want is the "Original Protectant" but I'd look at the ingredients before purchase.)
The second is the size/weight. I think some people try to compare worn-down balls with brand new and therefor full sized cue balls. A fair comparison should measure both the diameter and the weight. I remember when a proud new owner of a measles cue ball brought it into the PH and was surprised when it didn't draw well. The object balls he was trying to draw off of were old and visibly smaller than the cue ball.
The first is the surface. To see the extremes, don't bother to clean the cue ball for a week or two. Try some draw and spin shots. Then clean it with a ball polish such as Aramith's or Chem-Pak and apply a hard wax or a little silicone spray like Armor All. (I just looked at the current range of AA products and I guess what you want is the "Original Protectant" but I'd look at the ingredients before purchase.)
The second is the size/weight. I think some people try to compare worn-down balls with brand new and therefor full sized cue balls. A fair comparison should measure both the diameter and the weight. I remember when a proud new owner of a measles cue ball brought it into the PH and was surprised when it didn't draw well. The object balls he was trying to draw off of were old and visibly smaller than the cue ball.
Even this wouldn't work perfectly. The usual problem isn't the cue ball itself, but the difference in weight between the cue ball and the object balls. Different places will probably have object balls of different weights, so your personal cue ball will probably act differently.
pj
chgo
To wander way off topic:
Years ago, bicycles were made with steel. Then people started to experiment with aluminum. Aluminum bikes made with tubes the same size as steel bikes were not as stiff, and prone to failure.
Gary Klein, who was taking metallurgy at MIT, came up with the idea that by making the tubes much thinner walled but much larger in diameter, he could make the bike frame far stronger, and much lighter - the thinner tubes required much less material despite their much more massive appearance. Strength comes from the diameter, not the amount of metal
When he graduated be began building custom big tube aluminum bikes, a neat trick requiring top quality welding. And they were far stiffer and lighter than steel bikes.
The point is, the larger the diameter, be it aluminum tube or billiard ball, the more resistance it will have to deform when in contact with another object.
Perhaps the engineers in the crowd can pontificate on how much the rate of deformation of a billiard ball increases as the circumference decreases though wear. It certainly isn't linear.
The corollary is that the harder the material, the less it will wear, so top quality balls beat cheap stuff.
Years ago, bicycles were made with steel. Then people started to experiment with aluminum. Aluminum bikes made with tubes the same size as steel bikes were not as stiff, and prone to failure.
Gary Klein, who was taking metallurgy at MIT, came up with the idea that by making the tubes much thinner walled but much larger in diameter, he could make the bike frame far stronger, and much lighter - the thinner tubes required much less material despite their much more massive appearance. Strength comes from the diameter, not the amount of metal
When he graduated be began building custom big tube aluminum bikes, a neat trick requiring top quality welding. And they were far stiffer and lighter than steel bikes.
The point is, the larger the diameter, be it aluminum tube or billiard ball, the more resistance it will have to deform when in contact with another object.
Perhaps the engineers in the crowd can pontificate on how much the rate of deformation of a billiard ball increases as the circumference decreases though wear. It certainly isn't linear.
The corollary is that the harder the material, the less it will wear, so top quality balls beat cheap stuff.
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It seems to me that every time I've played with a red circle cue ball (was forced to last night) it seems to play lighter than the rest of the balls. Bottom english is exaggerated and it doesn't carom off other balls as naturally.
The red circle I used last night was fairly new as well... the actual red circle was very red and not worn at all.
The red circle I used last night was fairly new as well... the actual red circle was very red and not worn at all.
To wander way off topic:
Years ago, bicycles were made with steel. Then people started to experiment with aluminum. Aluminum bikes made with tubes the same size as steel bikes were not as stiff, and prone to failure.
Gary Klein, who was taking metallurgy at MIT, came up with the idea that by making the tubes much thinner walled but much larger in diameter, he could make the bike frame far stronger, and much lighter - the thinner tubes required much less material despite their much more massive appearance. Strength comes from the diameter, not the amount of metal
When he graduated be began building custom big tube aluminum bikes, a neat trick requiring top quality welding. And they were far stiffer and lighter than steel bikes.
The point is, the larger the diameter, be it aluminum tube or billiard ball, the more resistance it will have to deform when in contact with another object.
Perhaps the engineers in the crowd can pontificate on how much the rate of deformation of a billiard ball increases as the circumference decreases though wear. It certainly isn't linear.
The corollary is that the harder the material, the less it will wear, so top quality balls beat cheap stuff.
The geometric property your refering to is called moment of inertia. For a circular cross section, its equal to (pi*d^4)/64
So, a brand new ball would have an I of 1.258 in^4
a ball worn down .015 would have an I of 1.225 in^4
a reduction of about 3%, not too bad but could effect a shot for sure.
Eric
And the physics thingy is the CoR: Coefficient of restitution
http://hypertextbook.com/facts/2006/restitution.shtml
http://hypertextbook.com/facts/2006/restitution.shtml
File this under things you don't think about but might need to know. Now I know what some of the possible reasons were for my cue ball experience.
It was interesting to me to find out that the cue ball could be a factor in my cue's performance, i.e. in leading people to believe that the cue did not work as well as it should. This taught me to be sure to let people know that they should be familiar with the equipment and know how to adjust their stroke accordingly.
Thank you.
If memory serves, at this year's Super Billiards Expo 10-ball event, they switched to the red circle cue ball in the middle of the event, and many players were furious, among them Dennis Hatch, who took note of it in the TAR Podcast just preceding the Dechaine vs Hatch TAR match in early May.
How much difference did the change at the Super Billiards Expo event make and was it fair or not?
How much difference did the change at the Super Billiards Expo event make and was it fair or not?
It can make a difference in three major ways I can think of.
There are cue balls -- mostly on bar tables -- that will just not take a polish. Their surfaces remain rough. It will be hard to keep draw on those balls. Also, they seem to get and keep more chalk spots. If close draw is easy and distant draw is very hard, it might be due to the surface of the cue ball. Waxing may help but is not a good solution as the ball changes as the wax wears off.
Some balls have a higher COR (coefficient of restitution) than others. With a higher (more ideal) COR, the cue ball will be easier to draw and harder to follow. I've been told that for carom championships Aramith bounces balls off a steel block and the ones that bounce the highest are sent to the championship. I have no idea how large an effect this is for pool cue balls.
The material might wear faster. I think Aramith advertizes a surface treatment for some of their balls and presumably they will not wear as fast and may be easier to keep shiny.
One other thing to consider about cue balls is whether they are lop sided. Back in the 1970's everyone around here thought blue circle cue balls were the best. I bought my own and found out that it might roll off by 6 inches to the left or right on a long roll if the heavy side was to one side or the other. Later I saw a blue circle broken open and it had a core that was clearly put in off-center.
I haven't seen this problem recently.
I haven't seen this problem recently.
PhysicsGuyBrian
Registered
Minor Correction...and late night ramblings of a bored physicist
What you have quoted is the Area Moment of Inertia that corresponds to cross-sectional areas of structural beams and is not moment of inertia of a solid sphere.
Ironically, your result is not too far off :scratchhead:
The Moment of Inertia for a solid sphere is: I = 2/5*Mass*Radius^2.
A worn down ball would have less mass and smaller radius. Let's see, if the diameter were worn down by a factor X then what would happen...
mass = density*volume where volume is 4/3*pi*radius^3 = 4/3*pi*(d/2)^3 = 1/6*pi*d^3 so
mass = density*1/6*pi*d^3.
Next we have I: I = 2/5 *mass*R^2 = 2/5*mass*(d/2)^2
Altogether now: I = 2/5* [ density*1/6*pi*d^3 ] * (d/2)^2 = 1/60 *density*pi*d^5.
let D = d*X where X is a fraction. Then the new moment of inertia value would be
I' = 1/60 *density*pi*D^5 = 1/60 *density*pi*(d*X)^5 = (1/60 *density*pi*d^5)*X^5
so I' = I*X^5
Now, new cueball should have 2.25" diameter and you used 0.015" as the worm reduction so lets see where that takes us...
X is the fraction that makes 2.25" go down BY 0.015". d = 2.25" and D = 2.235" so X = D/d = 0.99333333 forever repeating 3's. The new moment of inertia would be reduced from the original by exactly a factor of X^5 = (D/d)^5 = 0.9933333...^5 = 0.9671 truncated at four decimal places which is good enough.
This would be a reduction in moment of inertia of 3.29%. I hardly think most people would notice this but I suppose it is possible!!!
That's my 3.14 cents worth.
Cheers,
PGB
What you have quoted is the Area Moment of Inertia that corresponds to cross-sectional areas of structural beams and is not moment of inertia of a solid sphere.
Ironically, your result is not too far off :scratchhead:
The Moment of Inertia for a solid sphere is: I = 2/5*Mass*Radius^2.
A worn down ball would have less mass and smaller radius. Let's see, if the diameter were worn down by a factor X then what would happen...
mass = density*volume where volume is 4/3*pi*radius^3 = 4/3*pi*(d/2)^3 = 1/6*pi*d^3 so
mass = density*1/6*pi*d^3.
Next we have I: I = 2/5 *mass*R^2 = 2/5*mass*(d/2)^2
Altogether now: I = 2/5* [ density*1/6*pi*d^3 ] * (d/2)^2 = 1/60 *density*pi*d^5.
let D = d*X where X is a fraction. Then the new moment of inertia value would be
I' = 1/60 *density*pi*D^5 = 1/60 *density*pi*(d*X)^5 = (1/60 *density*pi*d^5)*X^5
so I' = I*X^5
Now, new cueball should have 2.25" diameter and you used 0.015" as the worm reduction so lets see where that takes us...
X is the fraction that makes 2.25" go down BY 0.015". d = 2.25" and D = 2.235" so X = D/d = 0.99333333 forever repeating 3's. The new moment of inertia would be reduced from the original by exactly a factor of X^5 = (D/d)^5 = 0.9933333...^5 = 0.9671 truncated at four decimal places which is good enough.
This would be a reduction in moment of inertia of 3.29%. I hardly think most people would notice this but I suppose it is possible!!!
That's my 3.14 cents worth.
Cheers,
PGB
Aramith CBs
At home, I typically use Aramith Red Circle cue balls. There are 5 that have been in use for several (3-5) years. They are cleaned with a home made polisher using Porper's Ball Polish. All 5 balls are between 164-167 gm. I have 2 unused Red Circle CBs, each weighs 168 gm. I have one unused Aramith logo CB that weighs 169 gm.
At home, I typically use Aramith Red Circle cue balls. There are 5 that have been in use for several (3-5) years. They are cleaned with a home made polisher using Porper's Ball Polish. All 5 balls are between 164-167 gm. I have 2 unused Red Circle CBs, each weighs 168 gm. I have one unused Aramith logo CB that weighs 169 gm.
Sealegs50:
I don't think it's the weight of the red circle ball that is the problem. Rather, if everyone will read the OP's opening post (post #1) again, you'll see that he suspects it's the MATERIAL in the ball that seems to make the red circle more bouncy / more zingy (with draw). Also, John Barton mentions an experiment he did with jumping various cue balls, and there IS a distinct difference that matches what the OP describes.
I myself hate the red circle cue ball. Put it this way -- Aramith have NEVER bundled the red circle cue ball with any of their ball sets (the red circle ball has always been a separate / standalone cue ball product) -- and there's a reason for that. The red circle is a specialty cue ball. It doesn't match any of the ball sets that Aramith sells. That's telling right there.
I'd rather play with the cue ball that comes with the ball sets out of the box. It's perfectly matched, both weight and material-wise. Failing that, a measles ball or a blue circle (original Centennial cue ball). Whenever I go to a pool hall and they give me a set of balls with a red circle cue ball, I ask for another ball set with a matched cue ball.
However unfortunate, a lot of folks (a lot of room owners as well) will swap the cue ball that comes with / is matched to the ball sets, and substitute a red circle ball. Why? Because more than 90% of the time, the game played with those ball sets is going to be short-rack rotation, and those players want to be able to "zing their rock" (i.e. be able to move it around the table with the least amount of effort). Nowadays, they've become DEPENDENT on the red circle ball, and it really shows when they try to use a regular cue ball, and complain that it's "dead." When in reality, the problem is their stroke / accuracy of their hit on the cue ball itself.
-Sean