Dwell Time and Throw Angle: Are These Terms Even Useful

[brokenball]

The more energy part is important to nail down what you mean. Obviously adding more and more sponge does not result in returning more energy. If it did our energy problems would be solved. So now how do you justify that thinker sponge is faster? Yes, it absorbs a high percentage of energy but what percentage does it return? The problem is that the compress rubber must not only accelerate the ball but it must accelerate the rubber that is returning to its original shape.
Did you have the blade part flat on the table?

Good on you for trying to test.

 

[UpSideDownCarl]

The OP's questions have been answered!

We have established that the terms dwell time and throw angle are incredibly useful. Useful for arguing about on the forums. Without in the slightest way changing anyone's understanding of how to hit a ping pong ball, or even how to choose equipment. So in that sense, utterly useless.

To be efficient, let's reserve the terms dwell time and throw angle for these argy-bargy engineering threads.

And ban them from proper threads about equipment and technique. There we can use normal words that don't pretend to scientific precision. Like fast, slow, feeling, spinny. We can define these as follows:

Fast = faster that whatever blade or rubber I am used to using
Slow = the opposite of fast
Spinny / Not spinny = see fast and slow above
Good / Bad Feeling = I like / don't like this blade or rubber

Suggestions of other plain language descriptors welcome.

I think I may need to change the rules to this thread so that only Brs is allowed to post.

 

[IB66]

Once again, "more energy" means a greater proportion of the total impact energy. But you already knew that. Why waste time on straw man distractions when you actually do address the question, here:

"Does rubber return a higher percentage of the energy it has absorbed relative to a blade? Not with a normal blade.
Bounce a ball of a bare blade then off a rubber mounted on hard wood like a cutting board. Which one returns the most energy/speed?"

Okay, I did it, sort of. Bare Viscaria vs T05H on Viscaria. Blades next to each other on a table, balls dropped from various heights. The balls bounce higher and more times off the rubber. Far from rigorous, but I'll stick with my hypothesis for now. The rubber blade returns more energy than the bare blade.

Imagine suspending a sheet of rubber / sponge without adding tension, and see how high the ball would bounce.
Do the same with a same sized piece of plywood.
Which would have the higher bounce?
If you added tension, similar to how a trampoline is set up, to the sheet of rubber / sponge, which would bounce higher? Tensioned rubber / sponge or un-tensioned plywood?
You could even test sponge on its own and rubber on its own (on a blade), which one would be more bouncy?

When combined the rubber / sponge / blade combination works much better, but which of the parts is contributing the highest % of energy returned to the ball?

 

[brokenball]

Imagine suspending a sheet of rubber / sponge without adding tension, and see how high the ball would bounce.

It wouldn't bounce very far. If you dropped a ball on it then you could measure the COR by taking the square root of the ratio of the height of the bounce to the height at which the ball was dropped from.

Do the same with a same sized piece of plywood.

It depends on the plywood. However, if you bounced off my cutting board it would bounce back almost as high as bouncing off a block of steel.

Which would have the higher bounce?

I would still go for the plywood. However, you should know that there are different types of plywood. Plywood made of soft woods will not bounce very high. Plywoods made of hard woods like my cutting board would provide a higher bounce.

If you added tension, similar to how a trampoline is set up, to the sheet of rubber / sponge, which would bounce higher? Tensioned rubber / sponge or un-tensioned plywood?

Have you tried it? This is a very good example. I bet the ball wouldn't bounce as high as you think. If you stretched ONLY the top sheet you would get a higher bounce. Why? I would bet that a ball bouncing of a hardwood plywood would still bounce higher.

Think about this some. The problem is that no one thinks. They only repeat myths and bad info.




You could even test sponge on its own and rubber on its own (on a blade), which one would be more bouncy?

When combined the rubber / sponge / blade combination works much better, but which of the parts is contributing the highest % of energy returned to the ball?

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[Der_Echte]

I would be interestd to see the variable of change of grip pressure be measured and quantified.

 

[langel]

I would be interestd to see the variable of change of grip pressure be measured and quantified.

It would be great to see some BB formulas on the MOG's grip.

 

[brokenball]

A person's grip would be difficult to measure but it would be relatively easy to measure the grip a vice has on the handle. It would require a load cell and computer to measure the grip. If the load cell and amplifier are fast enough it should be able to detect the ball impact.

Having what I call "soft hands" is key to blocking short with 0X LPs since there is no sponge to absorb energy.

I don't see why no one seems to understand that sponges absorb energy and dampen vibrations..