What causes high throw?

Speedplay wrote: Define a "few hundred years ago", cause back in the year 700 (or thereabout) a Brittish monk named Beda expressed in writting that the earth had to be round. Was he the only one? Probably not, as even the ancient greeks knew it. Late during the 1100th century, there was a book (used fo educational purpose) named "Elucidarius", where it clearly states that the earth was round. So, assuming that people thought the earth was round "only a few hundred years ago" is buying in to the myth. I do hope you have a better understanding in your own area of expertice, even though I haven't proved you wrong here, I'm sure you will make a great comback that proves you are right, as always.

Trying to score points again?  You obviously don't understand the word few.

Again, you miss the point.  It isn't about the few that knew, it is about the fact that everyone else was wrong for so long.

Speedplay wrote: I do agree with Baal that friction plays a huge roll when it comes to throw angle.

Baal didn't mention friction, at least not in this thread.  

If friction was all there was too it then tacky Chinese rubbers would have the highest throw.  Obvious this isn't the case.

It is amazing how much crap I get when I say I will stay out then then you guys want to drag me back in.  OK.

Dr 'feel the power' Baal wrote: Order of "throw angle" in Tenergy series is T05>T25>T64. Speed is T64>T05>T25.  Pip size is T25>T05>T64, which is same order of top sheet hardness.  The pip radius on T25 is at least 40% greater than T05.  Sponge is same.  Grippiness of top sheet is same.  Suggests there is an "optimum" pip size for what most people describe as throw angle, which is really the racket angle they have to use to execute a particular shot.

Pip size? If all it takes is pip size then every TT manufacturer could duplicate that in no time.

Edited by pnachtwey - 10/08/2012 at 12:56pm

My theory on "throw" (and I think I agree with pnachtwey on this)

pnachtwey wrote: Lots of stupid things.

Given your definition of few, as in a few hundred years ago, i assumed that few was very flexible. Now, as for the "few" who knew about the earth being round, most historicians of today belive that these "few" where in majority. So, trying to score points? Against you? No way, that would be way to easy, simply trying to teach you something new, as you seem so inclined to teach others.

Now, as for friction, you might know that most chinese rubbers comes with a very hard sponge, this prevents the ball from penetrating the rubber/sponge, which means less friction. Gee, I thought this was your area of expertice, but obviously not.

Finally, this isn't my native language, I'm sure I've made lots of spelling errors and stuff, but, I do understand the word few, as well as the phrase "huge roll". You seem to think that "hugh roll" equals "all there was to it". No one have ever said that friction was all there was to it, but I stated that it was one important factor. Baal made it clear in one of his posts that there where many factors to consider, which is what I agree with. I dare to say that Baal agrees with me that one of these factors is friction.

Again, you are proving that you are nothing but a wasted education. Such a shame to waste a good education on someone who haven't got the brain to understand it.

@Anton, thanks for the links you provided, I'll look in to them now, perhaps I get a better understanding of the word "few"

chopchopslam wrote: My theory on "throw" (and I think I agree with pnachtwey on this) The throw height of any given rubber is equal to the spin:speed ratio. Any slow, grippy rubber will always have high throw (like Barracuda). Any fast, less grippy rubber will always have low throw. (like Gambler Outlaw)

I actually tend to agree with this too, but there are a lot of  factors that go into determining that ratio, including sponge, top sheet surface and pip shape and size (diameter, length, orientation) underneath.

pnacthwey also seems to think that I believe that only pip size/shape goes into it.  I never said that.  He knows I didn't say that either, he just likes to try to score what he thinks are debating points.    Clearly it does play a role (see Tenergy series).  The value of that series is pip diameter is the only thing changing.  Also, I have played with all three, hence I know. 

My experience with really tacky rubbers is very limited -- I hate them -- and the ones I have used all have really dead sponge compared to the grippy ones like Tenergy, Bluefire, etc.  The correct comparison would be to put them all on the same kind of sponge.  I've never done that.  I doubt many people have.  I have no real dog in this fight except to say that there are probably lots of variables that manufacturers can play with to affect this quality we call throw angle.       


Edited by Baal - 10/08/2012 at 4:09pm

Hi MrScience,

I was interested in modelling the flight and spin of a table tennis ball before and after hitting a table tennis bat.
Attempted an excel sheet simulation and corresponding graph of the ball path.
In my quest for info to help with the modeling I stumbled upon the following http://www2.physics.umd.edu/~mfuhrer/course/spr02/AJP/AJP00482.pdf
The superball hard surface interaction is almost the reverse of the table tennis ball bat rubber interaction. A lot can be gleaned from this pdf. Ratio between tangential COR and perpendicular COR seems to me to govern whether a rubber is high or low throw.
Now hides and puts on flame proof suit. :)

Don,t forget that throwangle and throw height is not the same. Two bats can have same throwangle but different heigth (and length, ratio depends on batangle). Or same height different angle. High-angle combines but also confuses these two.
Maybe (I think so) the height is more related with topsheet/sponge elasticity. The angle is more related with deformation of the contactsurface between ball and rubber to the blade. Long pips for instance also have different throwangles but never a real high/long throw.

A ball doesn,t just make an indent in the rubber but spin also puts angular strain on the rubber. This makes that the contactsurface also angles to the bladeface. So bladeface angle is not the angle for the contact surface and incoming spin as well as outgoing spin affects this.

Speedplay,
Contactsurface also lowers the ratio for contactforce to surface area. So ten times more contact surface means ten times less pressure force per squared mm or any other specific area.

Friction per mm squared is ten times less then. But ten times as much area it has so 10 / 10= 1 /1 meaning no influence. In theory because when the firctionforce would be high enough to melt/soften the contactlayer the frictional coefficient would go down and then larger surface keeps more friction. This is significant for car tires (hence the width) but maybe not as much for tabletennis. (alltough..tacky rubber is viscous at room themperature allready and heavy counterspin I can imagine it plays a role).
Assumed there is no slippage between topsheet and ball, or not significant, a difference in friction doesn,t matter anyway.

Also keep in mind the difference between spin and rolling. A carwheel spins backward or forward means it has slippage to the road from accellerating or using breaks. When it doesn,t it rolls and spin to the wheel axis but not the road.  


Edited by mercuur - 10/09/2012 at 6:51am

ttgame wrote: Hi MrScience, I was interested in modelling the flight and spin of a table tennis ball before and after hitting a table tennis bat. Attempted an excel sheet simulation and corresponding graph of the ball path.

ttgame wrote: In my quest for info to help with the modeling I stumbled upon the following http://www2.physics.umd.edu/~mfuhrer/course/spr02/AJP/AJP00482.pdf The superball hard surface interaction is almost the reverse of the table tennis ball bat rubber interaction. A lot can be gleaned from this pdf. Ratio between tangential COR and perpendicular COR seems to me to govern whether a rubber is high or low throw.

Still a returnboard with tenergies would show the high throw it has (angle for a returnboard always has to be adapted for this) but won,t counter topspin from tack, pips or a technical cor.value.  So how relevant is playing topspin or countering for the topicquestion when the throwangle differences allready appear from this ?
Therefor I suggest to keep it to a passiv blocking returnboard first and make it not more complex then necessary to begin with. 







Edited by mercuur - 10/11/2012 at 6:46am