What makes a shaft whippy?

CeaseLess

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First what is a whippy shaft? A shaft with a lot of flex and vibration? Then is the only thing that makes a shaft whippy a small diameter, long, pro taper? Or are there other factors?
 
Taper is enough for me. That changes with CF but I have yet to go there.

Incidentally, there's this carbon tube weave that's not actually new but looks promising for pool sticks and maybe cloth as well.
 
Can you elaborate on the wood coming into play, admittedly I'm not too knowledgeable on the subject.
Some wood does not have as much "spine" as other wood.

There could be a variety of things that contribute to that.

The wood isn't aged enough, it doesn't have enough growth rings, high moisture content, grain runout, etc.
 
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The general term I like to use for this, is "spine". It's a term more commonly used in Archery, where they measure the stiffness of their arrow shafts (both wood and carbon fiber) in a numbered scale of 100-1000 spine. Spine strength is basically the overall rigidity of the given piece (shaft). In theory, longer and thinner objects have less spine, shorter and thicker objects have more spine (assuming working with wood and carbon fiber).

So, the spine of a cue shaft for the most part will come down to a few things. The type of wood used, the diameter of the shaft, and the length of the shaft. Carbon fiber is different, but still mainly comes down to the wall thickness and diameter / length.

Softer wood, longer shaft length, thin diameter (like 12mm) are going to make for a super whippy shaft unless counteracted like a lot of makers nowadays do.
 
First what is a whippy shaft? A shaft with a lot of flex and vibration? Then is the only thing that makes a shaft whippy a small diameter, long, pro taper? Or are there other factors?

This is pure structural mechanics stuff.

The stiffness of a shaft is proportional to the 4th power of its diameter and inversely proportional the the square of its length.
Given that the length of the shaft is essentially constant::
The stiffness is proportional to 4th power (d^4) its diameter integrated along the length of the shaft. {Timoshenko}

So, the thinner the shaft is, and the longer the taper is, the whippier it is.

Now as to taper, since diameter is increasing as the taper progresses, the tip of the shaft is a lot more whippy than 1/3rd of the way back, the tip is vastly whippier than 2/3rds of the way back. {50 years ago I could "do the math" but that day is gone}
 
Some wood does not have as much "spine" as other wood.

There could be a variety of things that contribute to that.

The wood isn't aged enough, it doesn't have enough growth rings, high moisture content, grain runout, etc.
Would any of things that make a wood softer, or have less spine, inherently lead that shaft to have more deflection then a shaft that has the same specs but with more spine?
 
The general term I like to use for this, is "spine". It's a term more commonly used in Archery, where they measure the stiffness of their arrow shafts (both wood and carbon fiber) in a numbered scale of 100-1000 spine. Spine strength is basically the overall rigidity of the given piece (shaft). In theory, longer and thinner objects have less spine, shorter and thicker objects have more spine (assuming working with wood and carbon fiber).

So, the spine of a cue shaft for the most part will come down to a few things. The type of wood used, the diameter of the shaft, and the length of the shaft. Carbon fiber is different, but still mainly comes down to the wall thickness and diameter / length.

Softer wood, longer shaft length, thin diameter (like 12mm) are going to make for a super whippy shaft unless counteracted like a lot of makers nowadays do.
Very interesting and informative. Couple questions. What would you look for when finding a softer wood that would play lively? Would you look at grain and growth rings, or is something else an indicator? What specs would you think to use for a shaft I described? Maybe a 30 inch shaft, 12mm, 17 inch pro taper. And how do makers counteract that, splicing and coring?
 
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