Stiffest Hardest Wood break shaft

McChen said:
there is a lot of confusion here...f=ma is the correct formula for "force", but this isn't the right formula to use when thinking about break cues. kinetic energy is what you want to use to calculate the power of a break cue. the f=ma formula gives you only the force required by your arm to accelerate the cue. to measure the impact on the cue ball, the kinetic energy formula 1/2mv^2 gives you amount of energy due the cue in motion.

The kinetic energy equation is useful to demonstrate the concept of why more cue ball speed is very important. But the fact is the cueball remains a constant mass regardless of who is breaking.

Kinetic energy is a scalar amount, and there are problems with trying to use that equation to calculate how much energy is actually imparted to the rack.

Force and acceleration are vectors, and if the discussion is about how to impart more energy to the cueball (the discussion is about cue woods, not about cueball phenolics), and not what properties of a cueball impart more energy to the rack, then the force equation is the more appropriate concept.

Kelly
 
rhncue said:
Well, as my hero, Hillary, would say "I misspoke" about which formula is the correct one to attain the highest energy input into the cue ball for breaking a rack of balls. However, I do believe that I got across that just a lighter break cue doesn't necessarily equate to the best break cue for all. If they both are going 15 miles an hour I would much rather get hit by a bicycle than a freight train.

Dick


You need new heroes. :D

Kelly
 
Kelly_Guy said:
The kinetic energy equation is useful to demonstrate the concept of why more cue ball speed is very important. But the fact is the cueball remains a constant mass regardless of who is breaking.

Kinetic energy is a scalar amount, and there are problems with trying to use that equation to calculate how much energy is actually imparted to the rack.

Force and acceleration are vectors, and if the discussion is about how to impart more energy to the cueball (the discussion is about cue woods, not about cueball phenolics), and not what properties of a cueball impart more energy to the rack, then the force equation is the more appropriate concept.

Kelly

but we are talking about the cue here, not the cueball. the discussion was how the weight of the cue affected the break shot. so the KE equation is for the energy within the cue (transferred to the cue ball) not for the cueball itself. we need dr. dave or bob jewett to chime in here!
 
McChen said:
but we are talking about the cue here, not the cueball. the discussion was how the weight of the cue affected the break shot. so the KE equation is for the energy within the cue (transferred to the cue ball) not for the cueball itself. we need dr. dave or bob jewett to chime in here!

Well, actually that was not the intent of my question.

I was wondering if a denser harder wood would be better for shafts used for breaking. What are the reasons if not?
 
McChen said:
but we are talking about the cue here, not the cueball. the discussion was how the weight of the cue affected the break shot. so the KE equation is for the energy within the cue (transferred to the cue ball) not for the cueball itself. we need dr. dave or bob jewett to chime in here!

Which is going to impart more force to a cue ball, a cue striking it traveling at 50 mph that is accelerating? or a cue striking it traveling at 50 mph that is slowing down? Your equation will yield the same value for both examples I gave, but a different force will be applied to the cueball for each example.

Which is going to spread the rack better, a cueball that is traveling at 30 mph that is still accelerating when it strikes the rack, or a cueball that is slowing down but strikes it at 30 mph?

The kinetic energy equation you gave, while serving to show how important velocity is, has its best application in a closed mechanical system. Net force imparted to an object is not a mere calculation of kinetic energy, it is the objects change in kinetic energy, again, which can be described as a vector, not a scalar.

Regarding wood of choice, once the cueball leaves the cue, it cares not what kind of wood it was hit with. What matters is the mass of the cue stick, the velocity and acceleration of the cue stick throught the shot, and the properties of the cue, shaft, ferrule, tip that affect how much energy is absorbed versus transferred to the cue ball, and ofcourse how well the cueball is addressed (off center hit, hitting down into the table creating a new variable in the equation etc). This means a fairly stiff shaft/taper, fairly hard wood, hard ferrule and tip, quality stroke, good timing, good mechanics, and a cue weight that is optimal for each person to yield the greatest force for him is what is desired.

Kelly
 
Kelly_Guy said:
Regarding wood of choice, once the cueball leaves the cue, it cares not what kind of wood it was hit with. What matters is the mass of the cue stick, the velocity and acceleration of the cue stick throught the shot, and the properties of the cue, shaft, ferrule, tip that affect how much energy is absorbed versus transferred to the cue ball, and ofcourse how well the cueball is addressed (off center hit, hitting down into the table creating a new variable in the equation etc). This means a fairly stiff shaft/taper, fairly hard wood, hard ferrule and tip, quality stroke, good timing, good mechanics, and a cue weight that is optimal for each person to yield the greatest force for him is what is desired.

Kelly

Ok, say we take shafts made of steel, ebony, maple, purple heart, ash, all with different diameters so they weight the same. Same tip and ferrule material. What will happen?

If they have the same weight they should inpart the same force. Will flex make a difference? Will the density make a difference?
 
Kelly_Guy said:
Which is going to impart more force to a cue ball, a cue striking it traveling at 50 mph that is accelerating? or a cue striking it traveling at 50 mph that is slowing down? Your equation will yield the same value for both examples I gave, but a different force will be applied to the cueball for each example.

Which is going to spread the rack better, a cueball that is traveling at 30 mph that is still accelerating when it strikes the rack, or a cueball that is slowing down but strikes it at 30 mph?

The kinetic energy equation you gave, while serving to show how important velocity is, has its best application in a closed mechanical system. Net force imparted to an object is not a mere calculation of kinetic energy, it is the objects change in kinetic energy, again, which can be described as a vector, not a scalar.

Regarding wood of choice, once the cueball leaves the cue, it cares not what kind of wood it was hit with. What matters is the mass of the cue stick, the velocity and acceleration of the cue stick throught the shot, and the properties of the cue, shaft, ferrule, tip that affect how much energy is absorbed versus transferred to the cue ball, and ofcourse how well the cueball is addressed (off center hit, hitting down into the table creating a new variable in the equation etc). This means a fairly stiff shaft/taper, fairly hard wood, hard ferrule and tip, quality stroke, good timing, good mechanics, and a cue weight that is optimal for each person to yield the greatest force for him is what is desired.

Kelly

acceleration isn't the factor here, the cue is not accelerating when striking the cue ball. this was proven in the jacksonville experiments using high speed cameras. no matter how a player tried, the cue was always at constant velocity when it reached the cueball. the acceleration/deceleration is way before and after the strike.

the question is how the weight/speed of the cue stick is related on a break shot. speed has much more effect than mass is the general point, which is what the KE equation says. anyways, this thread is getting way off topic and quite nerdy :)
 
Jeff said:
Ok, say we take shafts made of steel, ebony, maple, purple heart, ash, all with different diameters so they weight the same. Same tip and ferrule material. What will happen?

If they have the same weight they should inpart the same force. Will flex make a difference? Will the density make a difference?

Flex and compression does absorb some of the energy. If they all have the same mass, then some of the shafts would be really fat and some would be really super skinny (like the steel one).

Also, they may have the same weight, but would the friction vary enough in some they could affect the stroke? Maple is a very close grained wood, and can be sealed and burnished to be very smooth. I remember once picking up a cue with an aluminum shaft, and you couldn't hardly stroke it with a closed bridge. You need some give in shaft. If there is none whatsoever, any slightest amoung of off center hit is going to make things more difficult. You don't want too much give.

In my opinion, width adjusting the diameter of the shaft and adjusting the taper of the shaft, and selecting the shaft and butt by weight, there is absolutely nothing wrong with hard maple. I also like purpleheart for a break shaft for something a little heavier and stiffer while having a smaller diameter and comfortable taper.

Kelly
 
Jeff said:
I have always wondered why break sticks don't have shafts made from harder woods. Wouldn't a harder wood give a harder break?

I know about Ash shafts but other than that what else is possible to use besides Maple.

I imagine there is a very good reason why other woods can't/aren't used like Ebony, Teak, etc.

Can someone give a simple explanation?
Other woods can and are used. I have seen ebony break shafts. I have made lots of purple heart shafts for break cues. But I found the flat laminated maple gave a slightly stiffer hit than maple and yet did not kill the feel like many of the heavier woods do. So it is what I went to for break cues. Many of these heavier woods do not have good compression strength like maple does. This means they do not compress and spring back like maple does. Many also have very little bending strength. So they are more like hitting the ball with a solid material that does not really give much either direction. That can be a good thing for some people and a bad thing for other people. But my guess is it is a bad thing for more people as those woods have been tried and have not caught on. Purple Heart is about the only wood that has held on as a alternative break shaft in popularity. It is rough on the saw blades on my shaft machine and I hate the dust, plus the flat laminated maple became more popular, so I quit making the purple heart shafts.
 
So it is what I went to for break cues. Many of these heavier woods do not have good compression strength like maple does. This means they do not compress and spring back like maple does. Many also have very little bending strength.



for the woods listed earlier such as Purplepeheart,Ipe,Ebony,etc this statement couldn't be farther from the truth.i would say that for the most part heavy dnese woods are stronger tha Maple,and for the woods listed earlier thet are way stronger and stiffer.for it's weight Maple is nice and strong,but when you sart comparing it to heavy,dnese woods such as Ipe,Ebony,Cocobolo,Dyamondwood,Purpleheart,etc it isn't really close.
 
masonh said:
for the woods listed earlier such as Purplepeheart,Ipe,Ebony,etc this statement couldn't be farther from the truth.i would say that for the most part heavy dnese woods are stronger tha Maple,and for the woods listed earlier thet are way stronger and stiffer.for it's weight Maple is nice and strong,but when you sart comparing it to heavy,dnese woods such as Ipe,Ebony,Cocobolo,Dyamondwood,Purpleheart,etc it isn't really close.

Hard maple bending strength: 15,800 psi
Hard maple shearing strength: 2,330 psi
Hard maple stiffness: 1830 x 1000 psi

PurpleHeart bending strength: 19,200 psi
PurpleHeart shearing strength: 2,220 psi
PurpleHeart stiffness: 2270 x 1000 psi

Ebony bending strength: 21,200 -27,000 psi
Ebony shearing strength: 2,900
Ebony stiffness: 2,560 x 1000psi

Here are a few numbers. Bending strength is also called modulus of elasticity. Numbers for ebony vary a little depending on species and source. Shearing strength is strength parallel to the grain.

Purpleheart and ebony certainly have a higher janka and maximum crushing strength.

I do think numbers can sometimes be misleading when talking about cue woods, because there are many properties that affect how a piece of wood performs as a cue wood IMO.

There is a property simply called elasticity in addition to the modulus of elasticity. I believe hard maple may be higher in this. It involves an amount of recovery due to stress/strain. Ebony may have a higher bending strength, but comparing it to hard maple could be misleading. The same amount of stress applied to both hard maple and ebony of the same proportions, the maple would flex more because it has a lower bending strength. But, if you bent both pieces the same amount, I believe ebony would deform or snap first.

You also have impact bending, compression etc, and it is tough to get numbers for all of these different properties for comparison across species.

Here is a page with the various wood strength properties explained. I personally feel like several of them come into play when determining what woods would make a good cue shaft.

http://www.woodbin.com/ref/wood/strength_defs.htm

Kelly
 
sorry Chris,i was thinking of crushing strength,now i see where you were strictly talking about compressive strength.i still don't think Maple is higher than these woods,but it may be in the same realm,while the crushing strength is much,much higher than Maple.


i think crushing strength is important in cue wood as it is strength with the grain.
 
Pink liptus developed my mike Johnson years ago i have heard its the best
there are a few other cue makers that have copied but Mike was the pioneer on this one .
 
masonh said:
for the woods listed earlier such as Purplepeheart,Ipe,Ebony,etc this statement couldn't be farther from the truth.i would say that for the most part heavy dnese woods are stronger tha Maple,and for the woods listed earlier thet are way stronger and stiffer.for it's weight Maple is nice and strong,but when you sart comparing it to heavy,dnese woods such as Ipe,Ebony,Cocobolo,Dyamondwood,Purpleheart,etc it isn't really close.
Maybe strength is the wrong word to use. But maple will bend farther without breaking than most of the woods you mentioned above. And it has some memory to go back to the same place after doing so. It can give and spring back. What ever word would be right to use, it out performs all the above in that aspect as far as I know except for maybe Ipe which I have never heard of.
 
masonh said:
sorry Chris,i was thinking of crushing strength,now i see where you were strictly talking about compressive strength.i still don't think Maple is higher than these woods,but it may be in the same realm,while the crushing strength is much,much higher than Maple.


i think crushing strength is important in cue wood as it is strength with the grain.
What I am talking about is the ability to slightly compress and spring back. Most really hard woods do not do that as well as maple and therefore give less cue ball action. I need to go back and read my wood books to find the correct terminolgy.
 
Mike Johnson did not develop Lyptus wood.Lyptus is a trademarked branch of growing Eucalyptus trees in sustainable plantations in Brazil.
 
.........about which formula is the correct one to attain the highest energy input into the cue ball.........

Only my two cents :)

Here not so simple process takes place. There is no direct transfer of kinetic energy of breakcue to kinetic energy of cueball as is present elastic deformations. Shortly so. The law of conservation of energy but as the theory of elastic impact here operates.

In the beginning, kinetic energy of movement of breakcue is transformed to potential energy of deformation of system cueball-tip-shaft-butt. This potential energy collects and given to cueball for very short time of contact of a tip with cueball. This time - shares of second. Therefore the cueball has huge acceleration and cue has huge loadings.

Break shot can be described by means of " the theory of elastic impact ". I shall miss formulas. These formulas and methods of calculations can be found in directories, books and articles. But also formulas are not so important for us as precisely calculate of a cue is impossible. But regularity are important. The basic regularitys is such.

1. The less rigidity of system tip-shaft-butt along grain - the more time of contact but more loss for deformation of system tip-shaft-butt, less acceleration and as a result less speed of cueball after a shot. Therefore nobody use soft tips for break cues for example.

2. The higher rigidity of system tip-shaft-butt - the is less time of contact, but less loss on deformation, acceleration is higher and as a result speed of cueball after a shot is higher. But before the certain repartitions. Try to break with a steel core - any pleasure:). Therefore many use the most rigid tips for breakcues and the most rigid along grain wood. But not the most rigid, for example ebony or ipe. My preference the Hornbeam and Purple Heart. A firm mountain maple is good too.

3. The higher speed of breakcue at the moment of contact with cueball - the higher speed of cueball after a shot. Hence a task of the player to accelerate breakcue till the maximal speed on the minimal way.

Notice, I did not mention about weight of cue. It is important certainly too, but it is present only at calculation of elastic deformation at the moment of contact and has no direct influence on speed of a cueball after a shot. As the weight of cue always is much greater weights of a cueball that of essential influence on final speed of a cueball it does not render. Gaspard-Gustave Coriolis (1792 - 1843) in 19 century has determined weight of cue for billiards. He has proved in the book THEORIE MATHEMATIQUE DES EFFETS DU JEU DE BILLARD (MATHEMATICAL THEORY OF THE EFFECTS OF THE GAME OF BILLIARDS) that the weight of billiard cue should be approximately (if I am not mistaken) 2.4-3.2 weights of a cueball for the most effective transfer of energy, including rotation, to a ball.

Weight of the majority pool cues is from 3.1 up to 3.4 weights of cueball. Weight of breakcues from 2.8 up to 3.2 weights of cueball. The smaller weight of breakcues is subjective parameter and is caused by the physical data of the human (most likely really). To human is easier to accelerate a breakcue up to maximal speed on small distance than cue is lightweight .

Sorry for my bad English. Probably I not have named all terms correctly. Almost lecture has turned out. Probably an echo my former profession:) . I am Cand.Tech.Sci., the senior lecturer of faculty "Theoretical mechanics". And now I am cuemaker.:)
 
i dont think it matters about shaftwood. i use maple only but have used other woods. i throw a lighter cue faster. i generate more mph with a lighter cue at the contact point of the rack than i can with a heavier cue. these hardwood shafts may be stiffer but you are loosing more mph because of weight.

ive been on the gun a few times and was consistantly in the upper part of the 20's. 27,28,29. no matter what break cue i used. sledgehammer x breaker fury my players j/b i modified was the best. now i have the new omega and its very very close.

if you can get a few different break cues and get on the gun all these questions would go away. formulas and all that jazz
 
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Kinetic Energy Of Cueball

DBK said:
Only my two cents :)

. My preference the Hornbeam and Purple Heart.

Gaspard-Gustave Coriolis (1792 - 1843) in 19 century has determined weight of cue for billiards. He has proved in the book THEORIE MATHEMATIQUE DES EFFETS DU JEU DE BILLARD (MATHEMATICAL THEORY OF THE EFFECTS OF THE GAME OF BILLIARDS) that the weight of billiard cue should be approximately (if I am not mistaken) 2.4-3.2 weights of a cueball for the most effective transfer of energy, including rotation, to a ball.

Weight of the majority pool cues is from 3.1 up to 3.4 weights of cueball. Weight of breakcues from 2.8 up to 3.2 weights of cueball.

Sorry for my bad English. Probably I not have named all terms correctly. Almost lecture has turned out. Probably an echo my former profession:) . I am Cand.Tech.Sci., the senior lecturer of faculty "Theoretical mechanics". And now I am cuemaker.:)

Hello in Russia: Thanks for all the research and info. Very informative and
interesting.

Bob Flynn
denalicues.com
International Cuemakers Assn.
 
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