In praise of thinner tips

[3kushn]

This is all speculation but IMO it seems that miss cues with a smaller tip are simply flaws in stroke (or tip grooming) and more english with smaller tips is psycological.

If the radius is the same for all tip diameters tested it seems that the contact area between tip and CB is the same. I think the difference is, with a smaller tip is that it's easier to see exactly where the tip will (should) land on the CB but when aiming for extreme english it's a double edge sword. You may know where to hit the CB but since you're now swinging a more accurate tip size you need a more accurate stroke. A larger tip gives you more room for error against miscueing. But with an extremely accurate stroke you will be able to apply the same amount of english with a 13mm as a 10mm tip given the same radius. The advantage with slightly small than 13 mm tips is being better able to pinpoint or see where the tip lands. If we all had a perfect stroke all we would need is a tip size equal to whatever the contact diameter between tip and CB is. Maybe 2 mm? Just think how perfect we could be if we could control that!!

 

[zeeder]

A 13mm shaft is a tip diameter that is suitable for most people, including beginners, but as mentioned earlier, does not allow for extreme spin.

I don't know about that. I play with a 13mm tip and I can execute the following shot pretty consistantly and I would consider this to be extreme spin:

CueTable Help

 

[RSB-Refugee]

And if two tips have different curvatures, you can always increase the shaft offset on the one that's flatter to get the same maximum english.

Does reduced end mass allow greater offset, without a misscue? I know, it gives less squirt. Reduced squirt, it seems to me, would be a conservation of energy. Could it be the conserved energy, is put towards greater spin to speed ratio? I have no idea, so I am interested to see if, you think it might be possible.

Tracy

 

[Jal]

Does reduced end mass allow greater offset, without a misscue? I know, it gives less squirt.

If two shots are made with a high and low squirt cue, and with both tip offsets exactly the same and near the miscue limit, I would think that the lower squirt cue would have a slightly greater chance of a miscue. With the lower squirt cue, the force on the cueball is directed more straight ahead and less toward the center of the cueball. Imagine this force as being comprised of two components: one directed exactly toward the center of the cueball (compression), and the other tangentially to its surface (friction). The ratio of the latter to the former is the static coefficient of friction. As you go from a center ball hit to larger and larger tip offsets, this ratio becomes ever larger until the materials involved cannot maintain the necessary value and the tip begins to slide (miscue). The lower squirt cue needs a higher value to be maintained at any given tip offset since the force it produces has a larger tangential component relative to the compressive component, because it is more forward directed.

Reduced squirt, it seems to me, would be a conservation of energy. Could it be the conserved energy, is put towards greater spin to speed ratio? I have no idea, so I am interested to see if, you think it might be possible.

Hmmm...I'll have to think about that or take a closer look at Ron Shepard's paper on squirt. Both a high and low squirt cue could, in principle, obey the conservation of mechanical energy law equally well. That is, they could, ideally, lose no mechanical energy during the shot, or lose equal amounts (to sound, heat and permanent deformation). Before applying the conservation laws (energy and momentum), you have to assume some tip offset, which gives you a first approximation to the spin/speed ratio, and a very good one. From there it's a matter of refining it by some method of successive approximations to account for the endmass momentum and energy. Like I said, I have to think about it more, but I believe you're basically right in that the endmass's energy takes away more spin than linear speed. Perhaps one of the other technical persons can provide a better answer.

It is clear, however, that from a force point of view, a lower squirt cue does produce a higher spin/speed ratio. Not much, hardly at all as a matter of fact, but some. It does this because the more forward directed force yields a greater effective tip offset, or moment, from which the spin/speed ratio is directly determined.

Jim

 

[predator]

Interesting that most people here consider 12.75mm thin. I play with 11.75mm and don't think it is that thin. Now when I occasionally try 12.75mm shafts, they look (and feel) huge.

 

[Cornerman]

Interesting that most people here consider 12.75mm thin. I play with 11.75mm and don't think it is that thin. Now when I occasionally try 12.75mm shafts, they look (and feel) huge.

I don't know about anyone else, but I know I said "thinner," meaning less than the 13mm that has become some kind of standard, furthering the idea that going thinner isn't a bad thing.

Fred

 

[inthezone]

It is clear, however, that from a force point of view, a lower squirt cue does produce a higher spin/speed ratio. Not much, hardly at all as a matter of fact, but some. It does this because the more forward directed force yields a greater effective tip offset, or moment, from which the spin/speed ratio is directly determined.

Yeah, Ron's paper enlightened me on this very point.
By my calculations then, assuming a Zshaft causes 30% less squirt than an "average" shaft (Platinum's #'s), and all other things being equal, the Zshaft should produce a mere 5% more spin for the same forward speed.

It does seem from all the above observations of greatly increased spin from thinner shafts that there may be something else happening...

 

[Jal]

...By my calculations then, assuming a Zshaft causes 30% less squirt than an "average" shaft (Platinum's #'s), and all other things being equal, the Zshaft should produce a mere 5% more spin for the same forward speed.

I get similar numbers to yours. When I wrote the post I was actually thinking smaller, but you reminded me of the 5% figure, which I briefly double checked. It's interesting that you're using 30% for the Z-shaft reduction. At Predator's site they were saying 50% the last time I checked, but if you look at their data, it is about 30% (they used some funky arithmetic.) I'm wondering how you arrived at that number?

It does seem from all the above observations of greatly increased spin from thinner shafts that there may be something else happening...

Maybe, but I have my doubts. I don't dismiss the experience of players lightly, even if it contradicts simple physics, which may be too simple. But I think RSB_Refugee's explanation is more plausible at this point: people may tend to use a smaller radius on the thinner shafts. All else being equal and to a first approximation, for a given shaft offset a dime radius will produce almost 9% more spin than a quarter radius. Also, players might feel more comfortable going out farther on the ball with the smaller shafts? And several posters have indicated, if I read them right, that they don't feel that they get any noticeably less spin with a thicker shaft.

But if you have any additional theories....

Jim

 

[inthezone]

I get similar numbers to yours. When I wrote the post I was actually thinking smaller, but you reminded me of the 5% figure, which I briefly double checked. It's interesting that you're using 30% for the Z-shaft reduction. At Predator's site they were saying 50% the last time I checked, but if you look at their data, it is about 30% (they used some funky arithmetic.) I'm wondering how you arrived at that number?

I'm not sure now where I got the 30% - Platinum says 23.3% less than "average". At any rate I used 30% and I believe the 5% is quite close for this example. But 5% only means 5 more inches on a length of the table draw shot....?

Maybe, but I have my doubts. I don't dismiss the experience of players lightly, even if it contradicts simple physics, which may be too simple. But I think RSB_Refugee's explanation is more plausible at this point: people may tend to use a smaller radius on the thinner shafts. All else being equal and to a first approximation, for a given shaft offset a dime radius will produce almost 9% more spin than a quarter radius. Also, players might feel more comfortable going out farther on the ball with the smaller shafts? And several posters have indicated, if I read them right, that they don't feel that they get any noticeably less spin with a thicker shaft.

But if you have any additional theories....

Jim

That 9% number is pretty interesting - I checked it myself and get the same - may be a good way for some to get more control out of low squirt shafts...
I like RSB_refugee's thought too - seems natural to do that.

Still seems a bit of a mystery though

Steve