Tip hardness and deflection
- Thread starter qguy
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Posts have been made before that assert the tip hardness has nothing to do with cue ball squirt.
I do not have a robot to prove my position, but I believe that theoretically, a softer tip should result in less squirt.
The reasoning is a bit lengthy, but here goes:
A softer tip should have more friction on the cue ball than a harder tip. Why? Well, imagine an infinitely hard tip, or at least a tip as hard as a ball. I think everyone here would agree that ball-ball friction is generally less than tip-ball friction. (If someone disagrees with that assertion, please explain why.)
More friction at the cue tip transfers more of the axially-directed force of the cue stick to the cue ball, ... than less friction at the cue tip does. Think of this as the "throw effect" between the cue stick tip and the cue ball, analogous to the "throw effect" of a dirty/sticky CB on a dirty/sticky OB. We all acknowledge the effect of throw is to divert the OB a little bit from the contact line and toward the line of the original CB direction. By the same reasoning, friction between the cue tip and the CB results in diverting the CB a little bit off of the contact line and toward the original cue tip direction. (This is why squirt is not as big as the contact line between the cue tip and the CB.)
To me, a softer tip means more friction, and more friction means less squirt.
Whether the difference between a hard or a soft tip can be measured or not, I am not sure. But this is my position and I am sticking to it.
I do not have a robot to prove my position, but I believe that theoretically, a softer tip should result in less squirt.
The reasoning is a bit lengthy, but here goes:
A softer tip should have more friction on the cue ball than a harder tip. Why? Well, imagine an infinitely hard tip, or at least a tip as hard as a ball. I think everyone here would agree that ball-ball friction is generally less than tip-ball friction. (If someone disagrees with that assertion, please explain why.)
More friction at the cue tip transfers more of the axially-directed force of the cue stick to the cue ball, ... than less friction at the cue tip does. Think of this as the "throw effect" between the cue stick tip and the cue ball, analogous to the "throw effect" of a dirty/sticky CB on a dirty/sticky OB. We all acknowledge the effect of throw is to divert the OB a little bit from the contact line and toward the line of the original CB direction. By the same reasoning, friction between the cue tip and the CB results in diverting the CB a little bit off of the contact line and toward the original cue tip direction. (This is why squirt is not as big as the contact line between the cue tip and the CB.)
To me, a softer tip means more friction, and more friction means less squirt.
Whether the difference between a hard or a soft tip can be measured or not, I am not sure. But this is my position and I am sticking to it.
if you think tips have any influence on deflection .. then you don't know what deflection is.
deflection is caused by the endmass or weight of the last few inches of the shaft.. I don't know what the difference is in weight from the heaviest tip to the lightest.. but I will confidently say it's not enough to make any measurable difference in deflection
deflection is caused by the endmass or weight of the last few inches of the shaft.. I don't know what the difference is in weight from the heaviest tip to the lightest.. but I will confidently say it's not enough to make any measurable difference in deflection
Subscribed.
I'd love to hear more about this whatever the result. The more I play, the more I enjoy playing with a softer tip. I also enjoy low deflection and my current cue is really low deflection. I had a gen 1 Kamui Black SS on my previous player and I think once the tip is done on my current cue I'm going to go back that direction slowly.
I remember reading a older thread sometime ago talking about hardness of the Kamui tips and elasticity as well. I wasn't exactly grasping the differnce and how it effects squirt. Maybe if this thread gets contributed to more information will come out and shead some light on the whole thing.
I'd love to hear more about this whatever the result. The more I play, the more I enjoy playing with a softer tip. I also enjoy low deflection and my current cue is really low deflection. I had a gen 1 Kamui Black SS on my previous player and I think once the tip is done on my current cue I'm going to go back that direction slowly.
I remember reading a older thread sometime ago talking about hardness of the Kamui tips and elasticity as well. I wasn't exactly grasping the differnce and how it effects squirt. Maybe if this thread gets contributed to more information will come out and shead some light on the whole thing.
I would think a harder tip would put more spin on the cue ball and less squirt. The idea that a softer tip and more friction puts more spin is an old theory that is disproved with experience.
If the tip starts to slide on the cue ball, all bets are off -- that's a miscue. On a normal shot, as far as anyone can tell, the tip does not slide on the cue ball. As long as there is no sliding, the result should be the same for a high-friction contact and a relatively low-friction contact. Of course the high-friction contact will hold on at much larger offsets from a center-ball hit, but if you do not go there, you should not observe any difference.
The above assumes that the surfaces are either stuck or sliding. That's what's usually observed in pool shots.
I disagree.
I will agree with you that squirt (the correct term) is certainly influenced by end mass, probably moreso than by other factors, but I assert that tip hardness might be a factor also. (It may be marketing hype, but apparently the people at Kamui agree with me.)
Who has a robot to settle this?
shafts deflect.... balls squirt F.Y.I.
Shaft deflection is not a bad thing, ball squirt is. One of the reasons a low mass end shaft produces a straighter shot is because the shaft does not push the cue ball off line with it's mass as a heavy stiff shaft can, it actually deflects away after sending the cuebal on it's path. Bob Meucci was talking about this 35 years ago with his long taper shafts that many players said felt too flimsy. But that shaft flex did produce a truer cue ball line, Bob was right all along.
Bob Meucci has one, although many have discredited it (or how he uses it). Mr. Meucci told me that hard tips produce less squirt than soft tips. I'm ignorant of his reasoning.
See Dave Alciatore's article at http://billiards.colostate.edu/bd_articles/2008/aug08.pdf, the first figure at the top of the second page. Basically, a soft tip seems to generate a slightly larger amount of squirt.
Your over thinking things just play with what feels good to you
The above posits some fairly flawed physics reasoning.
A softer tip will not (NOT) have more friction than a typical harder tip (say 80-85 on the durrometer; but not a phenolic hardness-kind of tip say 95-99 on the durrometer). The softer tip does not have more friction because it is not the tip that creates the friction--it is the chalk crystals being held by the tip. The crystals bit into the surface of the CB and the leather at the same time and create the friction. The crystals are very hard (silica or corundum) and do not "turn into a powder" under the kind of forces available in a cue-tip to CB collision. Thus, as long as the chalk retains its abrasive properties, the contact friction is essentially independent of the tip hardness.
A soft tip delivers LESS axial force to the CB (where axis is down the length of the shaft) because durring the moment of contact, it deforms more than a harder tip. This deformation takes energy away from the contact, and the CB axial acceleration is reduced.
Simultaneously the soft tip remains in contact with the CB for a (very slightly) longer time. And contact that is away from the center of the CB will result is (ever so slightly) more squirt due to the contact time being (slightly) longer (and end mass remaining the same).
Slightly less axial force, slightly more contact time cancel out and the soft tip delivers no more spin to the CB.
Yep. Exactly my point. My posts have been consistent on this point.
The OP was probably referring to ball squirt, though it is a common misnomer to call it deflection. I assumed he meant squirt. (No big deal if he used the "technically incorrect" word. We have all been guilty of it.)
No one really cares about shaft deflection, except as it reflates to squirt.
We all care about squirt: the CB deviating off the original aiming line whenever english is applied.
They also sell $25 chalk
. Must be the best if their website says so huh *Note there is sarcasm in this post.
I follow his graphics and his reasoning and now agree that a soft tip, for the reasons demonstrated by the robot (soft tip => longer contact time => higher effective end mass => more squirt), could produce slightly more squirt.
Thanks for the reference.
That could very well be true. On the other hand, a soft tip might have more flex to it, thus counteracting the potential increase in squirt from extended contact time.
Dr. Dave's tests were done with two different shafts, one with a soft tip and one with a hard one. As he acknowledges in the article, tip hardness was not really isolated as a variable. As such, I wouldn't draw any conclusions yet.
Jim