Tip hardness, bouncing balls, etc.

HawaiianEye

HawaiianEye

AzB Silver Member
Silver Member
With all the pool scientists telling us that tip softness/hardness has no effect on the amount of spin, etc., I got a question or two.

Pool and ping pong aren't exactly the same sport, but I think certain physics properties pertain to both.

Does a "soft skin" paddle equate to a "soft" tip?

Why do they think there is more "cling time" for a softer paddle to effect MORE spin, yet the pool doctors tell you the same principle doesn't apply in the case of pool cue tips?

Rubber rails have more "cling time" than harder rails and this includes temperature conditions, etc.

The following links may provoke some thought on the subject.

https://van.physics.illinois.edu/qa/listing.php?id=110

http://blog.paddlepalace.com/2011/0...-most-asked-table-tennis-equipment-questions/
 
HawaiianEye said:
Does a "soft skin" paddle equate to a "soft" tip?
Click to expand...
In other words, if a soft paddle spins a ping pong ball faster, why wouldn't a soft tip spin a cue ball faster?

There may be other reasons too, but the first one that comes to my mind is that the difference in friction between ping pong paddles is radically more than the difference in friction between cue tips. In fact, I think the difference in tip/ball friction between (well chalked) cue tips is essentially zero - there's no apparent slippage with either, and they have the same miscue limits.

It's a simple matter to compare different tips in a controlled way. I've done it with lots of them and have never found a difference - even phenolic jump/break tips are the same, except maybe for their miscue limit.

pj
chgo
 
HawaiianEye said:
Pool and ping pong aren't exactly the same sport, but I think certain physics properties pertain to both.

Does a "soft skin" paddle equate to a "soft" tip?

Why do they think there is more "cling time" for a softer paddle to effect MORE spin, yet the pool doctors tell you the same principle doesn't apply in the case of pool cue tips?
Click to expand...
FYI, I played table tennis at a fairly high level for many years and I have a really nice paddle, so I have an appreciation and understanding for how much spin can be applied.

A sticky-rubber ping-pong paddle grabs the ball completely without any slip (just like a well-chalked cue tip does, whether it is hard or soft). So the amount of spin one can apply with a good ping-pong paddle is limited only by the amount of tangential speed one can generate at contact with the ball. And in ping-pong, the paddle's forward and tangential speeds can be controlled and varied independently over a significant range of proportions. For example, with a "loop" shot involving significant topspin, the paddle has very little forward speed and a tremendous amount of tangential speed (almost straight up). One might think a swoop stroke in pool can create a similar action, but this is not the case because the action of a pool shot and the physics involved are very different.

A cheap ping-pong paddle (e.g., the hard-pip or sandpaper types) cannot grab the ball completely. The paddle surface slips across the ball when one attempts to apply significant spin. This is sort of like a miscue in pool, where the cue tip fails to grab the CB completely and slips off the surface (usually creating secondary contact with the tip, ferrule, or shaft). However, this is a really poor analogy since the physics of a pool shot is so different than the physics of a ping-pong shot.

The amount of spin a cue tip can apply (for a given cue speed) depends only on the effective tip offset from center, whether or not one swoops during the stroke. Now, a really hard tip might not be able to grab the CB as well as a soft tip, especially if it doesn't hold chalk very well, so the miscue limit, and maximum possible amount of spin,might be larger with a softer tip as compared to a really hard tip. However, for a normal non-miscue shot, a hard tip grabs the CB just as well as a soft tip and they each can apply the same amount of spin (assuming there is no miscue). The fact that the tip contact times can vary a little with tip hardness really has no practical effect on spin-generating capability.

Regards,
Dave
 
HawaiianEye said:
I know and I don't have time to look at it or clean it out.

I'm not shy, you can post anything you want in this thread.
Click to expand...

Well, when I saw 'you' it reminded me of a PM that I sent you, or thought that I sent you in regards to another thread. I'm now thinking that you may not have received it as I tried to follow up & got the your box is full thing.

I think that subject is probably a mute point by now.

Best 2 You & All,
Rick
 
dr_dave said:
The fact that the tip contact times can vary a little with tip hardness really has no practical effect on spin-generating capability.
Click to expand...
Speaking of that, I've always wanted to ask this:

[SIDEBAR ALERT]

A normal 1-2ms contact with side spin starts at one distance from center and ends a little farther from center. If it was possible to accelerate the CB the same amount with an instantaneous contact of zero duration, where in that contact arc would the instantaneous contact have to be to generate the same spin/speed ratio?

Or if that's not known, where would you expect it to be? I'm guessing at the middle of the normal contact arc, but wonder if it's the end...?

pj <- no good reason to ask
chgo
 
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Patrick Johnson said:
Speaking of that, I've always wanted to ask this:

[SIDEBAR ALERT]

A normal 1-2ms contact with side spin starts at one distance from center and ends a little farther from center. If it was possible to accelerate the CB the same amount with an instantaneous contact of zero duration, where in that contact arc would the instantaneous contact have to be to generate the same spin/speed ratio?
Click to expand...
Honestly, I don't know, but the three super-slo-mo videos embedded in the answer to the 2nd question in the following resource page can help provide some visual judgment:

"what causes squirt?" resource page


Patrick Johnson said:
Or if that's not known, where would you expect it to be? I'm guessing at the middle of the normal contact arc, but wonder if it's the end...?
Click to expand...
I would also guess that is close to the middle, maybe a little on the start side of the middle.

Regards,
Dave
 
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Patrick Johnson said:
In other words, if a soft paddle spins a ping pong ball faster, why wouldn't a soft tip spin a cue ball faster?

There may be other reasons too, but the first one that comes to my mind is that the difference in friction between ping pong paddles is radically more than the difference in friction between cue tips. In fact, I think the difference in tip/ball friction between (well chalked) cue tips is essentially zero - there's no apparent slippage with either, and they have the same miscue limits.

It's a simple matter to compare different tips in a controlled way. I've done it with lots of them and have never found a difference - even phenolic jump/break tips are the same, except maybe for their miscue limit.

pj
chgo
Click to expand...

You've gotta be able to actually cue a ball to see the difference, mind...
 
It's a simple matter to compare different tips in a controlled way. I've done it with lots of them and have never found a difference - even phenolic jump/break tips are the same, except maybe for their miscue limit.

pj
chgo
Click to expand...
Ron Swanson:
You've gotta be able to actually cue a ball to see the difference
Click to expand...
You have to hit the same spot on the CB. Anything more than that is your usual mythological silliness.

pj
chgo
 
Time?

Compression?

Expansion recovery from compression?

Different force required for equal compression of objects of different density?

Equal compression of objects with different densities requires different levels of force?

Recovery time from compression of different density materials from the same force used to compress them to different levels of compression?

Flat, straight on force vs. an angular application of force?

Natural coefficient of friction (without augmentation from a foreign substance) for different density materials under applications of angular force?

Different shaped material causing different angles of force & different compression levels for a given linear offset along an arc different than from a head on perpendicular force?

Different shapes for different densities of material?


Is there much going on in a one to one comparison during an extremely short time frame & distance of contact together?

How much scientific study has truly been done?

I just thought I'd add some questions to the OP's concerns.



Best 2 All,
Rick
 
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If there was anything to this don't you think that that all the best players would be playing with the same setup?


HawaiianEye said:
With all the pool scientists telling us that tip softness/hardness has no effect on the amount of spin, etc., I got a question or two.

Pool and ping pong aren't exactly the same sport, but I think certain physics properties pertain to both.

Does a "soft skin" paddle equate to a "soft" tip?

Why do they think there is more "cling time" for a softer paddle to effect MORE spin, yet the pool doctors tell you the same principle doesn't apply in the case of pool cue tips?

Rubber rails have more "cling time" than harder rails and this includes temperature conditions, etc.

The following links may provoke some thought on the subject.

https://van.physics.illinois.edu/qa/listing.php?id=110

http://blog.paddlepalace.com/2011/0...-most-asked-table-tennis-equipment-questions/
Click to expand...
 
As a follow-up, if a cue tip were made to extend the contact time significantly (e.g., by using a rubber material for the tip), the resulting squirt (CB deflection) would be "off the charts" and the cue would not be very usable (except for center-ball hits).

Regards,
Dave

dr_dave said:
FYI, I played table tennis at a fairly high level for many years and I have a really nice paddle, so I have an appreciation and understanding for how much spin can be applied.

A sticky-rubber ping-pong paddle grabs the ball completely without any slip (just like a well-chalked cue tip does, whether it is hard or soft). So the amount of spin one can apply with a good ping-pong paddle is limited only by the amount of tangential speed one can generate at contact with the ball. And in ping-pong, the paddle's forward and tangential speeds can be controlled and varied independently over a significant range of proportions. For example, with a "loop" shot involving significant topspin, the paddle has very little forward speed and a tremendous amount of tangential speed (almost straight up). One might think a swoop stroke in pool can create a similar action, but this is not the case because the action of a pool shot and the physics involved are very different.

A cheap ping-pong paddle (e.g., the hard-pip or sandpaper types) cannot grab the ball completely. The paddle surface slips across the ball when one attempts to apply significant spin. This is sort of like a miscue in pool, where the cue tip fails to grab the CB completely and slips off the surface (usually creating secondary contact with the tip, ferrule, or shaft). However, this is a really poor analogy since the physics of a pool shot is so different than the physics of a ping-pong shot.

The amount of spin a cue tip can apply (for a given cue speed) depends only on the effective tip offset from center, whether or not one swoops during the stroke. Now, a really hard tip might not be able to grab the CB as well as a soft tip, especially if it doesn't hold chalk very well, so the miscue limit, and maximum possible amount of spin,might be larger with a softer tip as compared to a really hard tip. However, for a normal non-miscue shot, a hard tip grabs the CB just as well as a soft tip and they each can apply the same amount of spin (assuming there is no miscue). The fact that the tip contact times can vary a little with tip hardness really has no practical effect on spin-generating capability.

Regards,
Dave
Click to expand...
 
HawaiianEye said:
I know--{my PM box is full}-- and I don't have time to look at it or clean it out.

I'm not shy, you can post anything you want in this thread.
Click to expand...

Yes, Mr. Eiaye, you have a PM from me, about a month old !...In it, I was inquiring as to why you were constantly getting on my case, when, in our first contact, I was very supportive of you when you were trying to promote the Manny Pacquiao/Efren vs. Joe Rogan/Strickland doubles match ! :(

Check it out --> http://forums.azbilliards.com/showthread.php?t=339660 -->(my 1st post, is #28)

It is considered 'rude' not to respond to PM's, so I was not overly surprised, that you didn't ! :cool:..Seems quite odd, you have plenty of time to talk about "ping-pong paddles", and trash Lou and I,. but you can't find time to clean out your PM box !

PS..Staying on topic..I wonder if I could hit a cue ball, hard enough (with a soft tip)..to make a 3-way carom, off 'yours'..RJ, and Bunter's noggin's ? :confused:....Bet I could ! :thumbup:
 
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SJDinPHX said:
...

...PS..Staying on topic..I wonder if I could hit a cue ball, hard enough (with a soft tip)..to make a 3-way carom, off yours..RJ, and Bunter's noggin's ? :confused:....Bet I could ! :thumbup:
Click to expand...

Sir,

Would that be an endorsement for a soft tip?

If so, would you care to elaborate as to why?

I think your thoughts & opinions would be of value, one way or the other with proper reasoning.

I'm in the New Orleans area. There are times that I change shafts to get a different tip so as to not have to change my stroke & take time to find the right stroke for spin when a simple tip change does it & allows me to keep my stroke more consistent.

Please keep in mind that I am not a high tech kind of guy & have played off the wall quite a bit. I know that I would find the right stroke & feel over a bit of time but if I can feel that a simple tip change is a quick solution I will now often just make the change.

I hope you choose to avail us of your experience & opinions on the subject. Whether we agree or not.

Best 2 You & All,
Rick
 
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