Balance Point- How to measure correctly?
- Thread starter atthecat
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What you say is true. Same overall mass. I think the weight distrubution is more of a comfort thing. If people gripped only at the balance point it would hardly be noticable but most people grip behind the balance and that makes it more noticable. I think a lot of folks mistake this "comfort feel" for "hit feel". Probably why a lot of great cue makers get frustrated by players critcizing the "feel (hit)". of their cues.
Bob,
Yes it may be true that the ball may already be gone after impact.
but if you hit an open bridge topsin shot and hold any cue at the balance point of the cue it seems to skip of the top of the cueball which can cause a foul after the shot when the cue skips off and hit another ball close by.
Adding forward weight adds control to this particular shot it helps hold the cue with a downward force resisting the upward skipping action of the curvature of the cueball
So try holding farther and farther back hitting the same shot and see if your control of the cue after impact doesn't improve through the shot
Do you mean hard masse shots and jump shots?
Don't know....need Bob Jewett and Dr. Dave to give a physics lesson on that.
I agree completely that the center of gravity (balance point) has a strong affect on the playability of the stick. I mentioned above that I have trouble breaking with a balance point that is strange to me.
The point I was trying to make that didn't come across clearly is that for a given balance point it is more or less impossible to tell how the weight is distributed within the cue stick. It is not possible to measure the weight distribution by any static measurement (a measurement without motion involved). So, when someone remarks about how well balanced a cue is, I think they are only responding to the balance point.
super long post
I respectfully disagree, for the correct answere ask Tony at Black Boar. It has to do with the 2 nodial points of the cue. when A cue hits theCB it bends in 2 places creating a sin wave. The 2 points at which it bends are its nodial points where they are and how much flex in the cue will determine the length of time the tip has contact time with the CB, the difference between a short time and a long contact time is very small yet will yield a big difference as to how the CB responds.
Tony has explained this theory beyond like I did above to a much more detailed degree and makes sence of it, I dont remember it well enough to quote him. It did bring up alot of old memories of the 3 years of formal education I had in Physics, Chem, Math.
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For a discussion of the "empirical evidence"**, I have came up with. I have 2 Boars that Tony has built within a couple years of each other, the shafte are interchangable, So I took my daily player and the other boar "Test cue" and put my other shaft on it, they felt like 2 completely different cues. I switched the shafts and again they both felt the same as if I didnt switch shafts from one cue to the other.
My daily player felt much heavier with either shaft and I got more action/control of the CB. A friend who plays 4 balls stronger than me had the same experience during this experiment. The difference in weight of the shafts is 4 grams, butts weigh about the same(cant remember the exact number rite now). So 2 cues from the same shop, with amazing tollarances in all phases of construction, played and felt totally different yet had the same balance point.
Tonys conclusion, and I agree balance point as a number is meaningless, its how the cue feels when you play with it-thats all that matters. He can explain the science much better than I am able to. I ran test and the Butt of my daily player is just a better hitting cue, 20+ pro's have played with it and are amazed.
A cue is moving when your using it, its not static there in lies the answere.
Wish I could explain better
best
eric
**http://en.wikipedia.org/wiki/Empirical
I respectfully disagree, for the correct answere ask Tony at Black Boar. It has to do with the 2 nodial points of the cue. when A cue hits theCB it bends in 2 places creating a sin wave. The 2 points at which it bends are its nodial points where they are and how much flex in the cue will determine the length of time the tip has contact time with the CB, the difference between a short time and a long contact time is very small yet will yield a big difference as to how the CB responds.
Tony has explained this theory beyond like I did above to a much more detailed degree and makes sence of it, I dont remember it well enough to quote him. It did bring up alot of old memories of the 3 years of formal education I had in Physics, Chem, Math.
-----------------------------------
For a discussion of the "empirical evidence"**, I have came up with. I have 2 Boars that Tony has built within a couple years of each other, the shafte are interchangable, So I took my daily player and the other boar "Test cue" and put my other shaft on it, they felt like 2 completely different cues. I switched the shafts and again they both felt the same as if I didnt switch shafts from one cue to the other.
My daily player felt much heavier with either shaft and I got more action/control of the CB. A friend who plays 4 balls stronger than me had the same experience during this experiment. The difference in weight of the shafts is 4 grams, butts weigh about the same(cant remember the exact number rite now). So 2 cues from the same shop, with amazing tollarances in all phases of construction, played and felt totally different yet had the same balance point.
Tonys conclusion, and I agree balance point as a number is meaningless, its how the cue feels when you play with it-thats all that matters. He can explain the science much better than I am able to. I ran test and the Butt of my daily player is just a better hitting cue, 20+ pro's have played with it and are amazed.
A cue is moving when your using it, its not static there in lies the answere.
Wish I could explain better
best
eric
**http://en.wikipedia.org/wiki/Empirical
Question
If you have two sticks exact same length and exact same balance point
and you take a measurement say 3 inches behind the balance point
weighing the stick from there to the tip. Won't that give you some insight as to how the sticks are balanced or constucted
On say two 18 ounce sticks with a balance point at 50"
and you take a weight measurement with a new fulcrum at say 53" from the tip with the scale at the tip
One stick weighs zero (which tells you all the counter weight is 3 inches behind the balance point like a weight bolt)
The other weighs 5 ounces (a uniform weight distribution on an 18 ounce stick)
The point I was trying to make is that the balance point has no effect on playabilty it tells you nothing and is a useless stastic and has no effect on playabilty because like you said you don't don't know what weight is in front or behind it(weight distribution)
Its just an arbitrary point in the middle of the cue where the cue balances on your finger and since I have not seen many players shoot with their cue balancing on their finger it means nothing to me.
What is important where YOU hold your cue what is the optimal downward
force(forward weight) needed at the tip.
Thats the right question to ask (and research)
But even more imortant is how well a vertical cue balances on an open palm
not for playabilty but to impress the ladies:thumbup:
Eric I'm not sure it's a matter of Bob being incorrect. I think you provide what I was trying to explain. Would you say that both BB's are good hitting cues but one cue and shaft combo just works better for you? In other words it puts you more in your comfort zone?
No. For the same balance point, even if one stick has 90% of the weight in the ferrule and the bumper, it is not possible to tell with a static test where the weight is. Grip one cue in your left hand and the other cue in your right hand and if you have gripped them in the same place, the torque on each hand will be the same. This is very, very basic center of gravity physics/geometry.
On the other hand, if you put each of the cues on a needle fulcrum (at the balance point) and spun them in a horizontal plane, you could detect which one had more mass towards the ends by how hard it was to spin up and how quickly it wound down.
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I don't think your measuring method would work but I think your conclusion about the weight distribution is correct. To actually figure out weight distribution accurately you would need to use three scales, one at the tip, one at the bumper and one that you could move along the length plotting measurements from all three scales. This would also require a lot of math. Easier to just figure out if you like a a heavier shaft setup (tip,ferrule,shaft, joint pin,insert and collar).
No, this doesn't work. This is very basic physics.
No Bob is right there's no way to tell how the weight is distritubed
staticly
but placing the fulcrum where your hand goes and measuring to the tip
wouldn't that tell your the weight at the tip(downward vector)
total weight of the cue(forward vector)
with the speed of the cue you could determine the right amount of downward force needed to resist the skipping action of an
OPENBRIDGE (the only thing holding the cue down is gravity)
TOPSPIN shot say over another ball.
yes I realize you can compensate for a poorly balanced cue by elevating the butt during the stroke but there are those that want a level stroke and have a proper balanced cue to shoot with
I could stroke with a steel rod and it would never skip it would stay right through the cueball with the topsin shot and alway rest firmly in my open bridge...but on other shots because of all the weight at the tip the deflection would be through the roof
I realize its a trade off trying to find the optimal downward force (forward weight) needed at the tip so that you can use it for all shots
I mean the day may come where pool is like golf
A club for every shot or a cue for everyshot
A break cue, a jump cue,a topsin stick,a heavydraw cue,normal shooting cue...each designed for its suited purpose
but till that day comes we have to strive to find the optimal forward weight
for all the shots on the table and find the right trade off of weight distribution
That's always made the best sense to me.
Sorry to bump this older thread, but I have a question maybe some of you physics experts can answer.
Assume that two cues have the exact same weight. Wouldn't weight distribution effect the location of the balance point? I don't think it is simply a matter of each having an equal amount of weight fore and aft of the balance point.
Say one had most of it's weight in the tip of the shaft, whereas the other has it more toward the joint. Wouldn't leverage matter?
I know that holding something out with weight at the end I get much more pull and feel more heft due to leverage working against me. Whereas weight concentrated near my hands feels most like the actual weight that it is.
Assume that two cues have the exact same weight. Wouldn't weight distribution effect the location of the balance point? I don't think it is simply a matter of each having an equal amount of weight fore and aft of the balance point.
Say one had most of it's weight in the tip of the shaft, whereas the other has it more toward the joint. Wouldn't leverage matter?
I know that holding something out with weight at the end I get much more pull and feel more heft due to leverage working against me. Whereas weight concentrated near my hands feels most like the actual weight that it is.
Yes, the distance from the balance point is just as important as the amount of weight. So, if you added an ounce at the tip, it would shift the balance point just as much as two ounces added half way from the starting balance point to the tip. (Technically, the balance point -- center of gravity -- is the point for which the integral over the volume of the object of the density times the vector from the center to the incremental volume is zero.) Here is a Wikipedia article about it.
Bob's explanation probably is the reason why two cues with similar weight and balance points do not necessarily have the same feeling of weight when stroking.
As players get used to the LD shafts, the old conventional cues are going to feel odd. LD shafts tend to redistribute the weight from the tip end to the joint end due to tapers and reduced weight sections.
Chris
Thanks Mr. Jewett for the explanation. Much appreciated.
I've noticed that too. With a Predator for example, many of them come in under 4.0oz, particularly the original 314. And of that 3.8ish oz weight, even more of it is toward the rear of the shaft than a conventional shaft due to the low mass end for low squirt performance.
Instead of having a cue that for example, is a well center balanced cue that you "feel" the weight every where (neutral feeling or even), the lighter shafts create a feeling in the bridge hand of heft in toward the joint area. It's a little awkward.
The downside to this for my personal preference is that if the cue is butt heavy and using a LD shaft, it feels like there's not much out there in front. Too much weight distribution to my stroke arm, and little out there on my bridge. Feels unstable and wobbly. Especially when having to shoot a ball glued to the rail using a decent stroke. To me, it lacks the stability and confidence of sitting in my bridge more steady.
For more forward weighted cues, LD shafts are again a bit awkward for myself in that the "node" points are the joint in and metal collar and whatever weight in the butt. Rather than more evenly distributed along the length of the cue giving me that perception of a neutral center balance. Which is my preference. On those front heavy cues, in order to keep the weight to my liking, often requires having less weight at the butt (removing or changing weight bolts). Then my stroke arm experiences what my bridge hand does in reverse. Feels like I'm moving around this light thing in the back shoving around greater weight up front. Bad stability. Too much load on the front end.
For me, the best balance and distribution is whatever balance and distribution of weight, according to my bridge length and stance gives a neutral or center balance where both bridge hand and stroke arm feel enough weight for stability, but that neither is feeling any heft in front or behind being shoved around during the stroke.
I used to play with a 19 - 19.25oz cues. With LD shafts, this has changed to 18.5 - 18.75 in order to try and get a similar balance. Only way to compensate for mass lost at front end of the shaft is to decrease a bit behind the balance point. Shifting it forward just a bit.
I find it easier to adjust to a new cue weight than it is to adjust a new balance.
And I agree with the few who said balance point is best measured from TIP to balance point. That's the right way.
I've noticed that too. With a Predator for example, many of them come in under 4.0oz, particularly the original 314. And of that 3.8ish oz weight, even more of it is toward the rear of the shaft than a conventional shaft due to the low mass end for low squirt performance.
Instead of having a cue that for example, is a well center balanced cue that you "feel" the weight every where (neutral feeling or even), the lighter shafts create a feeling in the bridge hand of heft in toward the joint area. It's a little awkward.
The downside to this for my personal preference is that if the cue is butt heavy and using a LD shaft, it feels like there's not much out there in front. Too much weight distribution to my stroke arm, and little out there on my bridge. Feels unstable and wobbly. Especially when having to shoot a ball glued to the rail using a decent stroke. To me, it lacks the stability and confidence of sitting in my bridge more steady.
For more forward weighted cues, LD shafts are again a bit awkward for myself in that the "node" points are the joint in and metal collar and whatever weight in the butt. Rather than more evenly distributed along the length of the cue giving me that perception of a neutral center balance. Which is my preference. On those front heavy cues, in order to keep the weight to my liking, often requires having less weight at the butt (removing or changing weight bolts). Then my stroke arm experiences what my bridge hand does in reverse. Feels like I'm moving around this light thing in the back shoving around greater weight up front. Bad stability. Too much load on the front end.
For me, the best balance and distribution is whatever balance and distribution of weight, according to my bridge length and stance gives a neutral or center balance where both bridge hand and stroke arm feel enough weight for stability, but that neither is feeling any heft in front or behind being shoved around during the stroke.
I used to play with a 19 - 19.25oz cues. With LD shafts, this has changed to 18.5 - 18.75 in order to try and get a similar balance. Only way to compensate for mass lost at front end of the shaft is to decrease a bit behind the balance point. Shifting it forward just a bit.
I find it easier to adjust to a new cue weight than it is to adjust a new balance.
And I agree with the few who said balance point is best measured from TIP to balance point. That's the right way.
Absolutely agree with this. Good description too. This would be an ideally balanced and weighted cue for me. I think it gives the best control over the cue all the way to the tip.
Chris