Search:

I haven't resolved the problem with the simulations yet but it is clear to me the problem is with the coefficient of drag, Cd, and the Magnus coefficient, Cm. These are unitless numbers and are...

I found a problem. I have an initial ball speed of 40m/s which is too high. The higher ball speeds are about 30m/s.
I posted this problem on...

You better not be right! However, I don't have a better explanation for now.
Physics documentation uses ω as the symbol for rotation in radians per second.
A thousand curses on any nit wit that...

What I have found is, TRUST NO ONE. Not the players, not the physicist. Not all physicist are good. The same goes for engineers. Not all are good.
I am always skeptical. Even of my own work. ...

You guys should know by now I am a geek, nerd and skeptic. Just because I post this doesn't mean it is right. Math looks right but it doesn't seem right to me.
It is 8 pages long so a I posted a...

There is no equation for speed as a function of hardness. Only elasticity matters when it comes to COR. Stop believing all the crap on TT forums.
What hardness you choose is a matter of...

Yes! Engineers/physicist can't agree on the correct formula for the Magnus effect. I have found two sources that are almost the same except for a constant that is just a little different. Both...

I have simulations of TT ball trajectories. I started the simulation over 10 years ago. I haven't done much with they lately but since I am now retired, I have more time to do simulations. Years...

This made me laugh.

NO! It depends on the material involved.
https://www.engineersedge.com/coeffients_of_friction.htm
Do you see area in these equations?
Do you see pressure in these equations?
The idea of pressure...

What do you really get from boosting?
Much depends on how you play. If you play close to the table then speed is not as important as spin to point. Tacky rubbers are very good for brushing and...

I like 802-40. I gave a sheet to one of my practice partners and he likes it a lot. 802-40 can generate a lot of spin but it doesn't do as well at brushing an incoming top spin balls as a normal...

That is a generalization.
Also, physic professors are academics that don't get much real world experience.
There were some on the mytt forum that didn't seem to know anything.
TT coaches that...

I am civil. I haven't called you any names or USDC would jump all over me.
I am talking physics.


This is an example of what I am talking about.
This is nonsense.
It makes NO difference...

You made a comment that "softer rubbers generate way less spin"
Where is your proof!? You are just repeating something some other clueless person has said.
Most people on this site are completely...

Yes they would. In the end there is only the normal and tangential coefficient of restitution.
All this other stuff is just confusion to keep the ignorant, ignorant.


Do you think that cool...

Where is your proof? You are just repeating BS you have heard from other players.
BTW, my Rakza 7 Max soft is very spinny with the right strokes.


Who's definition? Why can't a soft rubber be...

Again, define grippy.


Is soft rubber spinnier or is it just more "grippy"
So why are the TT manufacturers pushing the latest fad which is hard rubber?

What about tacky rubbers? Is Rakza 7 a...

So there is nothing in between "catching" or "slipping"?

If you think about the physics of what you are trying to achieve the it is easier to zoom in on what is necessary to achieve the desired results. This is much better than a lot of trial and error...

What about rolling friction?
With or without sliding?
Rolling implies that the balls are moving across the face of the paddle.
I have high speed video taken at 2000 FPS. I have posted them here...

Obviously Yasaka is comparing apples and oranges.
If Yasaka meant friction, then why didn't they say so?
So how does the friction on one rubber differ from the other?

BTW, the coefficient of...

The Yasaka claim is bogus and trying to take advantage of people that don't know any better.
As an engineer I would as what are the units? Spin is easy, It is RPM, revs/second or even radians...

There are some good points made but they are stating the obvious. The dangerous vs safe shot concept and anticipation or getting ready for a possible return instead of standing there admiring your...

When playing for points, do not do the same serve twice in a row. Being able to vary the speed and most importantly, spin keeps the opponent adapting/guessing. You should have many variation of...