Cue Tip Contact Myth-Busting Truths in Super Slow Motion

[Patrick Johnson]

Do you get a chalk mark at slow speed?

Only if there's chalk on my tip.

Grip pressure most definitely has an effect.

lol - still nope.

Why a more delicate stroke for a harder tip?

It's been explained and re-explained. Like I said, read more slowly - especially the parts about "spin" vs. "spin/speed ratio".

pj
chgo

 

[jollyrodger]

Chalk mark in same place.
CB travels same distance.
CB returns to same place on near rail.

Do you have trouble seeing things like this accurately?

pj
chgo

can you shoot the same shot 10 times in a row at the exact same speed? if not then would that cause a difference in spin on the ball? if you were to measure the cue ball landing in a buffer of where the cue ball stops then you have a variance on the result. so you could same you have an idea. but not a confirmed result. because people will pick apart your experiment.

 

[pvc lou]

Only if there's chalk on my tip.


lol - still nope.


It's been explained and re-explained. Like I said, read more slowly - especially the parts about "spin" vs. "spin/speed ratio".

pj
chgo

Nuh uh.

 

[Patrick Johnson]

...energy transfer is a function of the coefficient of restitution (COR)

...a hard tip will have more energy transfer, but that energy is transferred both linearly and rotationally.

How many times do you have to hear this before it sinks in, lou?

pj
chgo

 

[WobblyStroke]

i think we are getting closer to agreeing lol . i have seen people stroke through the cue ball and jab at it. my assumption is that would also affect spin.


Also i just though another variable. are we talking new tip or old tip? because overtime leather absorbs moisture wouldn't that affect the effect of the cue tip on the cue ball?

My Kamui supersoft, even with some wear is going to be so much softer than a hard tip even beat down that there must be a significant gap in firmness. I can barely stand the feel of a medium lol.

If we are going to go as full on control as possible, I think we'd have to hit one tip, change it on the same cue to the other type and do the second bout of testing. FWIW, I used 2 cues that hit very similarly back to back. I wasn't so fiercely committed to exact results that I'd be willing to hang out at my cue maker's and test there.

In case it got lost in all the procedural discussions, my results were there was no difference except in feel. With the caveat that I did not test at very light speeds. I just made a move in my arm that repeats, saw where the ball ended up and then only counted other attempts that ended up within a playing card length of the initial finish position. It probably wouldn't make it into peer reviewed journals, but it was plenty close enough for me to be satisfied my initial impression of tip hardness and spinrate was wrong.

 

[Patrick Johnson]

Nuh uh.

You've finally boiled your scientific expertise down to a phrase.

pj
chgo

 

[dr_dave]

i have seen people stroke through the cue ball and jab at it. my assumption is that would also affect spin.

The “type” or “quality” of stroke does not affect the CB speed or spin. All really matters is the cue speed, cue elevation, and tip contact point at the instant of impact. For the reasons why, see:

stroke “type” and “quality effects

stroke “timing” effects

effects of light vs. tight grip

stroke acceleration

follow through

swoop stroke​

 

[WobblyStroke]

You've finally boiled your scientific expertise down to a phrase.

pj
chgo

Gotta say, good on you for not responding as I would have:
"Yuh-huh"

 

[Patrick Johnson]

can you shoot the same shot 10 times in a row at the exact same speed?

Maybe not. That's why you don't count the ones that don't go the prescribed distance.

if not then would that cause a difference in spin on the ball?

As has been explained several times in this thread and others: "spin" and "spin/speed ratio" aren't the same thing.

pj
chgo

 

[jollyrodger]

My Kamui supersoft, even with some wear is going to be so much softer than a hard tip even beat down that there must be a significant gap in firmness. I can barely stand the feel of a medium lol.

If we are going to go as full on control as possible, I think we'd have to hit one tip, change it on the same cue to the other type and do the second bout of testing. FWIW, I used 2 cues that hit very similarly back to back. I wasn't so fiercely committed to exact results that I'd be willing to hang out at my cue maker's and test there.

In case it got lost in all the procedural discussions, my results were there was no difference except in feel. With the caveat that I did not test at very light speeds. I just made a move in my arm that repeats, saw where the ball ended up and then only counted other attempts that ended up within a playing card length of the initial finish position. It probably wouldn't make it into peer reviewed journals, but it was plenty close enough for me to be satisfied my initial impression of tip hardness and spinrate was wrong.

i think that is my hangup. lol i do and am subject to peer reviews weekly for the things i do. i look at thing under a microscope and sometimes i come at simple discussions like this as if i was going to pass / fail the test lol. ultimately it does come down to how do you like the feel.

 

[pvc lou]

How many times do you have to hear this before it sinks in, lou?

pj
chgo

Scientific inquiry and knowledge do not work the same as brainwashing, Patrick.

Repeating something over and over does not make it so.

 

[jollyrodger]

Maybe not. That's why you don't count the ones that don't go the prescribed distance.


As has been explained several times in this thread and others: "spin" and "spin/speed ratio" aren't the same thing.

pj
chgo

i dont think you understand what this means either. because in a controlled environment speed would be the same always. so spin in theory should be the same unless the tip makes the difference. but you do you.

 

[pvc lou]

You've finally boiled your scientific expertise down to a phrase.

pj
chgo

I was responding in the same spirit as your post that I quoted.

 

[jollyrodger]

i would also like to do this experiment in a vacuum. it would be cool to see ALL variables isolated.

 

[WobblyStroke]

i think that is my hangup. lol i do and am subject to peer reviews weekly for the things i do. i look at thing under a microscope and sometimes i come at simple discussions like this as if i was going to pass / fail the test lol. ultimately it does come down to how do you like the feel.

And that is I think the big take away for me as well...FEEL. I satisfied my curiosity with my lil experiment but in the process found that I don't even care if I saw the hard tip spin more, I still wouldn't switch to using one bc I don't like the feel, I don't like the sound, and I get what I need out of my soft tips. Sticking with em.

 

[jollyrodger]

And that is I think the big take away for me as well...FEEL. I satisfied my curiosity with my lil experiment but in the process found that I don't even care if I saw the hard tip spin more, I still wouldn't switch to using one bc I don't like the feel, I don't like the sound, and I get what I need out of my soft tips. Sticking with em.

i suck so bad at pool i just play with what ever is on the cue i bought LMAO

 

[Patrick Johnson]

...in a controlled environment speed would be the same always. so spin in theory should be the same unless the tip makes the difference.

That's correct. But again, "spin" (RPMs) isn't the topic here - spin/speed ratio (RPMs-per-FPS) is.

You might want to consider what that means.

pj
chgo

 

[pvc lou]

My Kamui supersoft, even with some wear is going to be so much softer than a hard tip even beat down that there must be a significant gap in firmness. I can barely stand the feel of a medium lol.

If we are going to go as full on control as possible, I think we'd have to hit one tip, change it on the same cue to the other type and do the second bout of testing. FWIW, I used 2 cues that hit very similarly back to back. I wasn't so fiercely committed to exact results that I'd be willing to hang out at my cue maker's and test there.

In case it got lost in all the procedural discussions, my results were there was no difference except in feel. With the caveat that I did not test at very light speeds. I just made a move in my arm that repeats, saw where the ball ended up and then only counted other attempts that ended up within a playing card length of the initial finish position. It probably wouldn't make it into peer reviewed journals, but it was plenty close enough for me to be satisfied my initial impression of tip hardness and spinrate was wrong.

So far only side-spin off the rails has been considered. What about draw? What about cut spin induced throw?

Hard and soft do the same? I don't think so.

 

[WobblyStroke]

One note on the experiment and why PJ's method may actually be better than the cue rig...
Assuming that efficiency of energy transfer is better for a hard tip (proven and agreed upon I hope), the same swing of the same cue will actually produce slightly more speed (and spin) with the harder tip. Probably within the range of acceptable length of shot (and therefore speed) BUT by accepting only shots that travel the same distance we actually isolate the spinrate better than by controlling the swing of the cue which in theory should produce slightly different speed and length shots due to hit efficiency.

 

[pvc lou]

One note on the experiment and why PJ's method may actually be better than the cue rig...
Assuming that efficiency of energy transfer is better for a hard tip (proven and agreed upon I hope), the same swing of the same cue will actually produce slightly more speed (and spin) with the harder tip. Probably within the range of acceptable length of shot (and therefore speed) BUT by accepting only shots that travel the same distance we actually isolate the spinrate better than by controlling the swing of the cue which in theory should produce slightly different speed and length shots due to hit efficiency.

That's a good point. Worth consideration.