Not again about boosting please

[UpSideDownCarl]

This forum is full of the blind leading the blind.
Only those that see get banned.

You have never gotten banned for information. You have gotten banned because you are rude and insulting to people. You are an adult and yet still you are acting like a child.

 

[tabletennisdaily1]

The drop test works but it only tests and one impact velocity. Tieffenbacher showed that the normal COR changes depending on impact speed.

You seem not everyone knows what I think is obvious.
Normal is like perpendicular only perpendicular only applies to a line. Normal is similar but it applies to a plane. A flag pole is normal to the ground.
Tangential would be any motion or force along that plane that is normal to the flag pole. Now since the earth is round, a plane that is is normal to the flag pole would leave the ground as the distance between the point on the plane and the flag pole increased.

So when the ball hits the paddle, the two exert a force on each other. The force the paddle exerts on the ball can be broken down into a normal force and a tangential force. So there is a tangential and normal COR. The normal COR affects speed and the tangential COR affect spin. The COR number are between 0 and 1 but for most modern rubbers they are probably between 0.6 and 0,7. A normal COR of 0.7 means that if the ball hits the paddle at a speed relative to the paddle of10 m/s it will have a normal rebound speed of 7 m/s relative to the paddle but if you are moving the paddle towards the ball at 5 m/s the ball will be moving at 12 m/s relative to the ground/ table.

If the paddle has a tangential COR of 0.5 and the paddle is moving horizontally at 10 m/s is horizontal. The ball will travel forwards at 5 m/s or or less. Much depends on the force of impact. The tangent COR changes depending on the impact speed. Obviously, to me anyway, that if the ball only drops from 1 cm that the ball will not impact with enough force to to grip and propel the ball forwards with back spin.

I have been posting the Tiffenbacher document for years and now realizing the few understood any of it.
https://deltamotion.com/peter/TT/199408014 - Tiefenbacher - Impact.pdf
Tieffenbacher is German so he used the term Epar and Tpar for Normal COR and Tangentia GOR.
Pay attention to the second small paragraph.

Thanks for fleshing out how tangential COR would be found (with drop test I was just thinking of normal COR, but tangential COR can be found too with a moving paddle). Also, thanks for posting the link to the Tiffenbacher paper so it is immediately accessible to the thread.

In the experimental setup to find COR, and as referred to in the Tiffenbacher paper, the ball's initial rotation is also necessary for a complete description of the rubber. Also, the ratio between the initial vs final rotation with respect to COR would seem to be an valuable metric to consider too. Now, if only there were a person who could create this experimental setup and take these multitude of measurements for a variety of rubbers and blades.

Going back to what started this discussion, I still disagree with your statement that "only the normal and horizontal coefficients of restitution matter". Rather, only "what tested effect does rubber #1 vs #2 have with my technique" or "what rubber feels better to play with" or "what rubber makes me win more/play at a higher level" matters on a practical level. COR data would be nice to have, but is not directly helpful, and certainly is not the only things that matter.

 

[lodro]

Going back to what started this discussion, I still disagree with your statement that "only the normal and horizontal coefficients of restitution matter". Rather, only "what tested effect does rubber #1 vs #2 have with my technique" or "what rubber feels better to play with" or "what rubber makes me win more/play at a higher level" matters on a practical level. COR data would be nice to have, but is not directly helpful, and certainly is not the only things that matter.

Indeed indeed.

Including in the list of just about completely irrelevant data we unfortunately have to add the often complete waffle that
represents a "sales pitch" from the manufacturers, like for example their numbers that are supposed to represent things
like SPEED GRIP SPIN etc.

As for my little experiment, it also means nothing at all and was never really meant to.

I am still watching patch 2 and 3 though because I am kinda wondering why they have not stretched themselves out at all.
Especially patch 3 as it had its last application on the 25th of December 2022

 

[latej]

I am still watching patch 2 and 3 though because I am kinda wondering why they have not stretched themselves out at all.
Especially patch 3 as it had its last application on the 25th of December 2022

You also don't exhale very rapidly unless someone pounds you into stomach. Maybe the rubber feels the same

Last week sick. Today gonna make my rubber exhale.

 

[lodro]

You also don't exhale very rapidly unless someone pounds you into stomach. Maybe the rubber feels the same

Last week sick. Today gonna make my rubber exhale.

Do you think it stays happily curled up because i did not kick it in the guts ????🤣
I remember from my previous life as a warrior that when I kicked the opposition in the guts (or thereabouts 😁) it was exactly
when they really curled up.
But your observation now leads us to the question : " Does the boosting stay longer when the rubber is left at idle. ? And to reverse the question:
" will the boosting disappear quicker if the rubber is used often ????

What say you ?

 

[latej]

Do you think it stays happily curled up because i did not kick it in the guts ????🤣
I remember from my previous life as a warrior that when I kicked the opposition in the guts (or thereabouts 😁) it was exactly
when they really curled up.
But your observation now leads us to the question : " Does the boosting stay longer when the rubber is left at idle. ? And to reverse the question:
" will the boosting disappear quicker if the rubber is used often ????

What say you ?

I don't know. It's a process, we see it changes the top-sheet, so I'd expect it to make an effect to the sponge too. But I've never measured it, just as many other things, because I knew it would not change anything, I'd still pound it the same, only I'd knew I'm the bad reason causing the need to re-boost, so I don't want to know You gonna spoil my day when you prove it!

 

[lodro]

I don't know. It's a process, we see it changes the top-sheet, so I'd expect it to make an effect to the sponge too. But I've never measured it, just as many other things, because I knew it would not change anything, I'd still pound it the same, only I'd knew I'm the bad reason causing the need to re-boost, so I don't want to know You gonna spoil my day when you prove it!

It is of course the way of the warrior to spoil the opponents day 😁

 

[BenjaminBenj]

Noope, if with not too much booster, it works absolutely ok.*

 

[The Pong Professor]

 

[lodro]

now we have the serious booster test against the cheap. not so serious test 😁

Quite interesting to me is the 60 hours final drying time and just how seriously some of the rubbers
are still domed AND also that in this strongly domed state the professor is going to glue the rubbers on to the blades

 

[Tinykin]

I admire the large amount of planning and work gone into the making of this video. Well done

 

[lodro]

What is the matter with all you experts ? It was a very simple question, please. " If one takes 2 identical rubbers and applies 3 layers of booster,
then glues one rubber on a blade and uses it regularly and stores the other rubber away" Which of the two rubbers looses its boosting effects earlier and why "????If you have no scientific explanation feel free to speculate, - I do. 😂

 

[dingyibvs]

What is the matter with all you experts ? It was a very simple question, please. " If one takes 2 identical rubbers and applies 3 layers of booster,
then glues one rubber on a blade and uses it regularly and stores the other rubber away" Which of the two rubbers looses its boosting effects earlier and why "????If you have no scientific explanation feel free to speculate, - I do. 😂

Should be the one that's played with. If the active ingredient is really just bicarb, then booster is basically slow-release soda. Agitation should cause release of gas just like shaking a can of Coca-Cola does until an equilibrium is reached.

 

[lodro]

Should be the one that's played with. If the active ingredient is really just bicarb, then booster is basically slow-release soda. Agitation should cause release of gas just like shaking a can of Coca-Cola does until an equilibrium is reached.

good thinking but remember one of the experts in this thread stated that , and I quote :"""Oil can seep into the sponge but gas can not escape""""

 

[dingyibvs]

good thinking but remember one of the experts in this thread stated that , and I quote :"""Oil can seep into the sponge but gas can not escape""""

Are you thinking of a different thread? I searched for the word "escape" and didn't find it in any of the pages. Maybe the confusion arises from the fact that what forms the gas in boosters, i.e. bicarb, cannot escape, just like how bicarb cannot escape a can of soda. Once it becomes CO2 though it can certainly escape, the same as a can of soda going flat. Slower if you don't touch it, but eventually it'll happen until an equilibrium is reached.

Gas can't escape easily, however. In fact, trapping air within bubbles is the entire premise of bouncy rubbers as that's what gives them the extra bounce over a solid sheet of elastic polymer.

 

[lodro]

Are you thinking of a different thread? I searched for the word "escape" and didn't find it in any of the pages. Maybe the confusion arises from the fact that what forms the gas in boosters, i.e. bicarb, cannot escape, just like how bicarb cannot escape a can of soda. Once it becomes CO2 though it can certainly escape, the same as a can of soda going flat. Slower if you don't touch it, but eventually it'll happen until an equilibrium is reached.

Gas can't escape easily, however. In fact, trapping air within bubbles is the entire premise of bouncy rubbers as that's what gives them the extra bounce over a solid sheet of elastic polymer.

I have been quoting YOU, in this thread posts #29 and #32

If gas can escape then it has really no reason to stay in there at all kinda like pulling the valve out of a bicycle tire.
Of course if the process you describe, where bicarb is transforming itself into gas, and if this is a slow process, then this could be the explanation.

 

[brokenball]

I am back from camping. No TV, No Cell, No internet, no water. I can see you guys haven't got anywhere.
I have said this on a different thread. The smaller the molecule, the faster it can diffuse through a solid. That is why H[sub]2[/sub] is used to test how well 1 and 2 liter bottles will hold the fizz which is basically CO[sub]2[/sub]
Hydrogen is a much smaller molecule than carbondioxide.

 

[brokenball]

You have never gotten banned for information. You have gotten banned because you are rude and insulting to people. You are an adult and yet still you are acting like a child.

Show me the rude and insulting comments!
The last one said that HE, Michael Zhang, knew about dwell time when I said he did not.
I think the word you are look for is dismissive.
They are ignorant. I could use the word idiots, but idiots can't learn whereas ignorant people can learn once they have been educated/informed.
I have found the TT forums to be extremely slow learners.

 

[lodro]

I am back from camping. No TV, No Cell, No internet, no water. I can see you guys haven't got anywhere.
I have said this on a different thread. The smaller the molecule, the faster it can diffuse through a solid. That is why H[sub]2[/sub] is used to test how well 1 and 2 liter bottles will hold the fizz which is basically CO[sub]2[/sub]
Hydrogen is a much smaller molecule than carbondioxide.

It was a very simple question, please. " If one takes 2 identical rubbers and applies 3 layers of booster,
then glues one rubber on a blade and uses it regularly and stores the other rubber away" Which of the two rubbers looses its boosting effects earlier and why "????If you have no scientific explanation feel free to speculate, - I do. 😂

 

[tabletennisdaily1]

Show me the rude and insulting comments!
The last one said that HE, Michael Zhang, knew about dwell time when I said he did not.
I think the word you are look for is dismissive.
They are ignorant. I could use the word idiots, but idiots can't learn whereas ignorant people can learn once they have been educated/informed.
I have found the TT forums to be extremely slow learners.

Brokenball, I understand that you can be frustrated, but you have to understand, being dismissive helps no one. Rather, try to debate or educate in an calm, friendly, eloquent, and descriptive manner. This is the best way to be persuasive and improve the quality of discussion.