Daily Table Tennis Chit Chat

[NextLevel]

Hey, I have a quick question.

Up to a point, I can brush loop nowadays. However only with a fairly conservative swing.

If I attempt to swing faster, the ball won't go out nor is the pace high, and there will be spin, but it will be lacking. On impact, I can hear a instantaneous tire-screeching sound. It doesn't feel too good.

What is happening here? Am I not sinking into the sponge enough? Is the angle of impact simply too sharp and it's like a ricochet? It feels like the topsheet is getting overloaded and letting go halfway.


Progress with my normal loops is going great. A lot of pieces are falling together. I just don't entirely understand how I could improve from this and why it happens. Thanks.

It's hard to address any of this without videotape.

 

[UpSideDownCarl]

It's hard to address any of this without videotape.

Yep. Video necessary. And a "tire-screeching sound" on impact.....sounds like someone has a good imagination. But I doubt that topsheet to ball contact sounds like what you have described.

 

[Archosaurus]

I suppose I should provide video.

Carl, that's the closest I can think of. It sounds like a toned down tire-screech, or the sound some erasers make if you brutally misuse them, whatever.

In other words, what rubber sounds like when it's sliding on a surface.

Isn't that the topsheet being overloaded from too fine an impact?

EDIT: The sound is not loud, mind you, but it sounds just like you'd take the sliding sound of an old bias-ply and cut a very short segment out of it. A rubber screech.

 

[UpSideDownCarl]

I suppose I should provide video.

That will be the only way for anyone to help you. Descriptions on a subject like this will not actually SHOW what you are or are not doing.

 

[Archosaurus]

Good point. Somehow I thought this is a very common error and I would immediately get some insight.

 

[laistrogian]

Yep. Video necessary. And a "tire-screeching sound" on impact.....sounds like someone has a good imagination. But I doubt that topsheet to ball contact sounds like what you have described.

I don't see how swinging a blade fast on a ball can make a tire-screeching sound in the first place. I've been able to make loud friction sound when doing opening loop but the balls are always so-so speed with tons of spin.

Archo, if you "loop" hard in the first place, the sound will more likely come from the blade. But i doubt your setup really goes super fast in the first place

 

[NextLevel]

I suppose I should provide video.

Carl, that's the closest I can think of. It sounds like a toned down tire-screech, or the sound some erasers make if you brutally misuse them, whatever.

In other words, what rubber sounds like when it's sliding on a surface.

Isn't that the topsheet being overloaded from too fine an impact?

EDIT: The sound is not loud, mind you, but it sounds just like you'd take the sliding sound of an old bias-ply and cut a very short segment out of it. A rubber screech.

Part of the problem, Archo, is that you read a lot and you try to sound like a good player. You need to realize that good players rarely if ever speak about these things. If someone is supposedly overloading the rubber, their stroke is wrong. It's that simple. It's why I laugh when people talk about bottoming out or other such crap. If the ball does not do what I intended to do, I read the ball wrong or my stroke was wrong. I don't get into theoretical reasons for why if they are not related to the actual technique being applied (my stroke was too slow, fast, racket angle too open, closed etc.)

 

[Archosaurus]

If I wasn't doing something wrong, I wouldn't be posting about this, would I?

Obviously, something is wrong with how I touch the ball. That we know. I have seen how people do slow loops, and I am not doing it right, I feel.

I think I can reproduce this pretty easily, so I'll record it if I get the table to myself.

 

[NextLevel]

If I wasn't doing something wrong, I wouldn't be posting about this, would I?

Obviously, something is wrong with how I touch the ball. That we know. I have seen how people do slow loops, and I am not doing it right, I feel.

I think I can reproduce this pretty easily, so I'll record it if I get the table to myself.

Let's assume you are right - where did you get the concept of overloading the topsheet from? I have only read that precise phrase on one website and I have never seen a very good player discuss it.

In any case, please take your stuff elsewhere. Chit chat is for chit chat, not for Archo's new invented TT Dilemma.

 

[UpSideDownCarl]

I think I can reproduce this pretty easily, so I'll record it if I get the table to myself.

When you say, "get the table to myself" do you mean you are going to show us more self-hitting? Hopefully that isn't what you meant.

We would need to see footage of you actually trying what you are talking about vs a human. And you would want a camera angle where we can actually see what you are doing.

In any case, slow looping, for me is an issue of touch. I have never tried to do it. There are certain circumstances where slow looping is just the right shot in response to a particular ball. Then you do it. You don't try. You just do it.

But, in any case, asking a question about something like this, you always would need video. I realize that you are not comfortable with posting video of you actually playing. And that is okay. I get that. But, then maybe you shouldn't ask these kinds of questions if you aren't will to post video. Very similar dialogue has occurred as a result of you posting queries like this and then not being willing to post video.

So choose: either don't ask or post a video.


Sent from Deep Space by Abacus

 

[Archosaurus]

What I know about theoretical rubber behavior comes from race engineers and automotive engineering books.

Table tennis rubber hitting a ball and tire rubber moving along the ground is somewhat similar, but not really. So I'm inclined to not believe in the concept of overloading the topsheet. In some way, a tire causing friction which causes an accelerating force is like a table tennis rubber impacting a ball, causing friction and accelerating the ball. But not really. I don't see how you could actually make the topsheet slide without using some kind of machinery to cause racket head speeds never seen before. It's definitely possible to slide the topsheet and whoever says that you can apply an unlimited amount of force into spinning the ball as fast as you want is wrong, but for humans' case they're right.

Oh, and in the case a race engineer shows up, yes, friction "technically" lessens when you get closer to the limits of a tires' grip. Let's not get into that.

Well, that's been enough rambling for now. Is that a physics book? Gotta go.

 

[Shuki]

Only time I've ever experienced "too much" grazing, is when I graze ever so slightly that the rubber doesn't grab the ball at all. I just call that missing the ball even though it made a tiny bit of contact. And it's always near the bottom of my raquet.
Lower level players look at me confused when this happens like "what happened?" and I just tell them I missed.

 

[laistrogian]

Only time I've ever experienced "too much" grazing, is when I graze ever so slightly that the rubber doesn't grab the ball at all. I just call that missing the ball even though it made a tiny bit of contact. And it's always near the bottom of my raquet.
Lower level players look at me confused when this happens like "what happened?" and I just tell them I missed.

You mean like slippage? Ever since I play with poly balls, the balls tend to slip a lot more, especially when I was just started using it.

 

[Shuki]

You mean like slippage? Ever since I play with poly balls, the balls tend to slip a lot more, especially when I was just started using it.

It's just bad contact. If your stroke is grazing the ball and then you turn your hips/body to guide it, you'll make solid contact WITH the grazing. There's no reason that you shouldn't make contact with the wood of your raquet, no matter how finely you graze.

 

[NextLevel]

It's just bad contact. If your stroke is grazing the ball and then you turn your hips/body to guide it, you'll make solid contact WITH the grazing. There's no reason that you shouldn't make contact with the wood of your raquet, no matter how finely you graze.

Bullseye. The concept of purely grazing the rubber is a useful misconception - how would you project the ball forward if you didn't have impact with the wood, even when serving? You just experiment with degrees and get to a point of acceptance. But getting too theoretical will not do anything for your TT.

 

[UpSideDownCarl]

Right now I'm reminded of a cartoon version of PNut rambling on about Neuton's theories, tangential force, speed of racket, speed of spin of ball, formulas for calculation, and the how all that theoretical baggage just got in his way. If it did anything, it helped him stay in his bubble and think he could loop when he couldn't.

Now, Archo, stop trying to take theories that you may or may not have understood about race car driving and trying to apply them to table tennis.

Here is a flaw in the idea from a completely non-physicist perspective: race care wheels are big. Race cars are heavy. The wheels have all that weight on them. The ground is the ground. It is not a very light plastic or celluloid ball. Right now I am trying to think of a formula for how much force would have to be applied to change the spin of the planet from sidespin to topspin.

Even if I'm wrong about all this and there is a correlation and we could produce a formula to tell you exactly what is happening in your theoretical scenario, it's not what is happening when you hear phantom sounds of rubber screeching on ball contact. And the formula wouldn't help you improve your technique anyway. It would only serve to further confuse you. Oh....wait....I'm not so sure that is possible.

Allright, if you didn't realize, I am just clowning around and try and entertain myself.

But Archo, just go play some table tennis and have fun. When you are 25-26 and have a job and have the ability to play in a real club and get coaching, you will laugh at all this silliness.


Sent from Deep Space by Abacus

 

[ttmonster]

 

[Boogar]

About the tire scratching thing. I can relate, yesterday i trained with a junior of ours and everytime he topspinned the ball it made a scratching sound. He said its because his rubbers are worn out.
To me that makes sense, as the topsheet doesn't seems to have enough grip and the ball slips slightly and gets gripped again.

So maybe you need a new rubber.

 

[UpSideDownCarl]

Wait....do you think that machine can make my Tenergy play like new? Hahahahaha.


Sent from Deep Space by Abacus

 

[Archosaurus]

Carl, you're entirely right. My point is that especially the forces are very different between traditional engineering subjects like automotives and heavy machinery vs a table tennis ball.

It's known that REALLY big tires behave quite differently compared to teeny tiny ones. Even if made of pretty much the same compound. Normal cars are VERY heavy relatively and the effect of just a "little" bit of weight of a few hundred pounds onto the rear or front tires makes a huge difference in what actually happens. You don't get something like that with table tennis balls and rubber.

So, all of that goes in the trash. Hell, half the time, engineers don't *really* know what's going on with rubber when it slips.

Some principles are still the same though. More friction = generally more grip, more heat etc. But it's not so simple. Table tennis rubbers, at least modern ones, actually dynamically change properties when they hit the ball due to temperature change. It's designed and ESPECIALLY tacky rubber work around it. Tires do that too, but it's nowhere near as dynamic relatively speaking. This is why p-nut's theories were entirely wrong in the first place.

Now, forgetting all that mumbo jumbo, I'm very interested in NL's saying of sinking the ball into the wood.

When people talk about sinking the ball into the sponge, do they mean that? Varying degrees of "bottoming out" as some people like to call it? Is there such a thing as sinking too little or too much?

Some people on forums make it sound like the ball will entirely lose all spin and pace if you sink it as deep as it can go into the wood. I'm not too sure if anyone should believe that. What do you think?

EDIT:

@Boogar

No, it's most likely due to touch. My rubbers are fine, they've always been like this as far as I can remember and play like a hot knife into butter. Very grippy.