Deflection question, explain how a stiffer CF shaft has less deflection.

[dr_dave]

I'm not the PhD in the forum. But I do have my own evidence. Just because I'm not doing science doesn't mean I can't judge the lack of science or understanding. There's obviously room to improve our knowledge of shaft physics but God only knows why everyone has their head in the sand

The important piece you are missing is understanding how little the shaft flexes during the incredibly brief tip contact time with the CB. Most of the flex happens after the CB is gone. It might help to do a little more "homework:"

what causes squirt

cue tip contact time

cue flex and vibration

shaft endmass and stiffness effects
​

I know you said you read everything at the last link, but I doubt it based on your beliefs. Please check out all the info, explanations, illustrations, videos, articles, analyses, and links on that page if you want to improve your understanding. It doesn't help to keep spouting off anecdotes and idle challenges if you don't first have an understanding of the important principles.

 

[poolscholar]

The important piece you are missing is understanding how little the shaft flexes during the incredibly brief tip contact time with the CB. Most of the flex happens after the CB is gone. It might help to do a little more "homework:"

what causes squirt

cue tip contact time

cue flex and vibration

shaft endmass and stiffness effects
​

I know you said you read everything at the last link, but I doubt it based on your beliefs. Please check out all the info, explanations, illustrations, videos, articles, analyses, and links on that page if you want to improve your understanding. It doesn't help to keep spouting off anecdotes and idle challenges if you don't first have an understanding of the important principles.

Do some real science Dave come on lol

 

[dr_dave]

Do some real science Dave come on lol

You're funny ... like a clown.

 

[JPB2]

Do some real science Dave come on lol

Not a very scholarly response is it?

 

[poolscholar]

There's peer review in science. Try that on any video on YouTube

If anyone does any real testing and science be sure to use close to miscue point to generate maximum deflection. Most players aren't comfortable using maximum side spin. With a high deflecting cue you should be able deflect 4 inches at least

 

[Patrick Johnson]

Do some real science Dave come on lol

You wouldn't know "real science" if it introduced itself (as you've demonstrated with your ignorant reactions to Dr. Dave's excellent work).

pj
chgo

 

[straightline]

Think about a diving board. Why does it need to flex and what happens when it's too stiff

The contention is that contact is broken before stored energy can be released into the ball.

 

[Reed Foley]

I am not knowing the answer to your question. However you bring up something I’ve wondered about myself:

Deflection isn’t just squirt. It is the sum total of squirt and swerve.

I have a hard time judging swerve.
I have a better feel for squirt.

For example, O.B. 1/2 ball off long rail with C.B. a little steeper than a half ball hit. If I want to bring C.B. across table to opposite long rail I might aim a little thicker than if I want to double the rail across.

I don’t think that I’m accounting for swerve just the initial squirt. If I get the feel for those shots with my cue, why would I want to change to something else that might be negligibly different.

Good wood is gonna keep getting harder and harder to find.

That is the real reason for CF and shafts that are laminated with maple and trash.

 

[SSP]

You're funny ... like a clown.

C'mon Dave, give him a break....he has done some real science, his high speed ego is on full display....

 

[SSP]

There's peer review in science. Try that on any video on YouTube

If anyone does any real testing and science be sure to use close to miscue point to generate maximum deflection. Most players aren't comfortable using maximum side spin. With a high deflecting cue you should be able deflect 4 inches at least

Definition of Peer Review, one scientist agrees with another scientist on something they are unable to prove, since they both agree it is now considered "settled science ".......

 

[ctran]

hi @dr_dave

thank you for all your detailed study and sharing, they have been most completes source of info I can find anywhere.

here in Vietnam, they players are circulating incorrect understanding about cueball deflection, they described to me "use extreme english at low speed with carbon shaft like Cynergy, you will see that the shaft makes cueball deflect a lot", I saw that they were saying about the deviation of the cueball from the original moving direction, which is precisely swerve

I show them your image anytime.

 

[ctyhntr]

Deflection reduction requires a reduction IN MASS at the front-end of the cue. A stiffer shaft MIGHT deflect a lil more but it doesn't have to. Some CF shafts are both stiff and lo-defl. To get lo-def. in a wood shaft requires either smaller size/conical taper or hollowing out. Short light ferrules help also. Anything to reduce mass.

I remember when the ads for OB1 & Predator 314 emphasized the laminated construction method. When Meucci black dot came out, many were suprised the shaft wasn't low deflection and assumed the lamination was responsible for lower deflection. I see the same misconception with carbon fiber shaft buyers.

 

[Patrick Johnson]

Some CF shafts are both stiff and lo-defl. To get lo-def. in a wood shaft requires either smaller size/conical taper or hollowing out. Short light ferrules help also. Anything to reduce mass.

Sounds like my 10mm conical hollow point (3/8” ferrule, stiff hit and 20-inch squirt pivot length).

pj
chgo

 

[garczar]

I remember when the ads for OB1 & Predator 314 emphasized the laminated construction method. When Meucci black dot came out, many were suprised the shaft wasn't low deflection and assumed the lamination was responsible for lower deflection. I see the same misconception with carbon fiber shaft buyers.

Lamination just helps with radial consistency, has nada to do with deflection. A LOT of people bought laminated shafts and just assumed it was lo-def. Same thing with cf, there are standard/sorta low/really low defl. cf shafts.

 

[iusedtoberich]

This thread is still going?

What were the early CF junk shafts 20 years ago? The Walmart specials. I forget were they all CF like the modern ones, or were they a wood core wrapped with CF?

 

[skor]

This thread is still going?

What were the early CF junk shafts 20 years ago? The Walmart specials. I forget were they all CF like the modern ones, or were they a wood core wrapped with CF?

Those were not CF, you had wooden shafts that were coated with fiberglass or graphite.

 

[Paul_#_]

What were the early CF junk shafts 20 years ago? The Walmart specials. I forget were they all CF like the modern ones, or were they a wood core wrapped with CF?

An el cheapo, Sportcraft C 6 12 Carbon Graphite, had a metal ferrule over a longer, about 5-inch, plastic ferrule. The plastic ferrule was inserted into the carbon graphite rod (and the metal ferrule). The carbon graphite rod was glued to the plastic and metal ferrules.
Photos of a blue Sportcraft with its metal ferrule intact and a black Sportcraft with the metal ferrule cut off.

 

[garczar]

Not even close, the majority of CF shafts out there are higher deflection. If you've only tried the becue and predator shafts, then I might believe it though. I've hit with several CF shafts that were higher deflection than LD wood shafts, and even non LD wood shafts for that matter. Most of the asian CF blanks that are out there are impossible to make lower deflection without drastic modification.

Not the one's i've tried and that's all i go by. Even the highest def. cf shaft i've tried was less than solid maple.

 

[ShootingArts]

"Real science" and peer review held that the world was flat and the sky a half dome over it. Also that the earth was the center of the universe. A lot of our science of today will be just as bad although we are as unwilling as the scientists of that day to believe it.

There are a few issues with the conversation as always. For starters, terminology. We call high deflection shafts "low deflection" because we are talking about the effect they have on the cue ball, not the effect of the impact on the shaft. Starting off with bass ackwards terminology is bound to lead to confusion.

Second source of confusion, we are talking about effective end mass, not end mass. As has already been proven, effective end mass is affected by both the stiffness of the shaft and it's ability to deflect. If a tip can't deflect it's end mass can be practically zero and it would still cause great deflection in the cue ball. Mount a "low deflection" shaft in linear bearings an inch or less from each end and it becomes low deflection no more.

While conventional wisdom holds that only the mass a few inches from the tip matters, I have spent time with a 12 ounce 11mm diameter at the tip house cue with the soft plastic ferrule that comes with a house cue. That combined with the heavy cue ball in use at the time had more deflection of the cue tip than the low deflection equipment of today.

Very flexible tip and ferrule, very low mass of the entire cue, the result was that making standard allowances for deflection that worked with a standard house cue I missed the object ball several inches when the balls were six feet apart. None of the shafts marketed as low deflection have given me that result. With apologies to Barbara Mandrell, I was low deflection when low deflection wasn't cool!

Pool wasn't a priority in my life at the time and it took me several months to make that cue work. Only three of us had those cues, sixty inch snooker cues with milk duds, and I proceeded to win the weekly pool tournaments until I had to quit, I was bad for my friend's business as everyone else knew they were shooting for second place.

Cue ball control was unreal with that cue and after mastering pinpoint cue ball placement with that cue for six months or so I found I could have control to ridiculous levels with any cue on the wall. I beat some of the very best, them using their cue with a hinge in it, me playing off the wall. Only fair to admit that was with cues I played with a lot and in rooms I knew very well and they didn't.

Too late now, but I wish the shafts would be referred to properly as high deflection shafts. It would save a lot of angst and I think promote understanding. When the shaft deflects a lot, the cue ball deflects a little and vice-versa.

My dollar and a quarter worth, inflation has been a bitch lately!(grin)

Hu

 

[garczar]

"Real science" and peer review held that the world was flat and the sky a half dome over it. Also that the earth was the center of the universe. A lot of our science of today will be just as bad although we are as unwilling as the scientists of that day to believe it.

There are a few issues with the conversation as always. For starters, terminology. We call high deflection shafts "low deflection" because we are talking about the effect they have on the cue ball, not the effect of the impact on the shaft. Starting off with bass ackwards terminology is bound to lead to confusion.

Second source of confusion, we are talking about effective end mass, not end mass. As has already been proven, effective end mass is affected by both the stiffness of the shaft and it's ability to deflect. If a tip can't deflect it's end mass can be practically zero and it would still cause great deflection in the cue ball. Mount a "low deflection" shaft in linear bearings an inch or less from each end and it becomes low deflection no more.

While conventional wisdom holds that only the mass a few inches from the tip matters, I have spent time with a 12 ounce 11mm diameter at the tip house cue with the soft plastic ferrule that comes with a house cue. That combined with the heavy cue ball in use at the time had more deflection of the cue tip than the low deflection equipment of today.

Very flexible tip and ferrule, very low mass of the entire cue, the result was that making standard allowances for deflection that worked with a standard house cue I missed the object ball several inches when the balls were six feet apart. None of the shafts marketed as low deflection have given me that result. With apologies to Barbara Mandrell, I was low deflection when low deflection wasn't cool!

Pool wasn't a priority in my life at the time and it took me several months to make that cue work. Only three of us had those cues, sixty inch snooker cues with milk duds, and I proceeded to win the weekly pool tournaments until I had to quit, I was bad for my friend's business as everyone else knew they were shooting for second place.

Cue ball control was unreal with that cue and after mastering pinpoint cue ball placement with that cue for six months or so I found I could have control to ridiculous levels with any cue on the wall. I beat some of the very best, them using their cue with a hinge in it, me playing off the wall. Only fair to admit that was with cues I played with a lot and in rooms I knew very well and they didn't.

Too late now, but I wish the shafts would be referred to properly as high deflection shafts. It would save a lot of angst and I think promote understanding. When the shaft deflects a lot, the cue ball deflects a little and vice-versa.

My dollar and a quarter worth, inflation has been a bitch lately!(grin)

Hu

Yep, the MORE the shaft deflects the LESS the cueball deflects. More is less and less is more. I think.