Ladies and Gentleman, Dreams do come true

[TensorBackhand]

how about Zero-calibration ??

how does it work?

 

[Lazer]

It depends on the head size togethether with the rubbers pore size. It is bound to be in exact with a small head. This tool sounds useless to me. You need one with a big head that can not sink into the pores.

Cheers
L-zr

 

[TensorBackhand]

It depends on the head size togethether with the rubbers pore size. It is bound to be in exact with a small head. This tool sounds useless to me. You need one with a big head that can not sink into the pores.

Cheers
L-zr

I dont think the metal ball fits inside a sponge pore

 

[lodro]

how does it work?

I would assume like a micrometerscrew, when you put the gadget on a hard surface, like a plate glass, and turne the screw -knob then when the measuring tip reaches the surface it will click and the unit tip is calibrated at zero. Just a guess though.

 

[Lazer]

I dont think the metal ball fits inside a sponge pore

It doesn’t need to fit. Its a % thing. This is why they say a minimum thickness for measurement. You want an average of both pores and solid rubber under the point. If you get too many pores you measure soft. If you get too much solid rubber you measure hard.

The more pores the worse the measurement.

Cheers
L-zr

 

[TensorBackhand]

It doesn’t need to fit. Its a % thing. This is why they say a minimum thickness for measurement. You want an average of both pores and solid rubber under the point. If you get too many pores you measure soft. If you get too much solid rubber you measure hard.

The more pores the worse the measurement.

Cheers
L-zr

So just measure multiple points on the rubber

 

[Lazer]

Then average will give a better result but it won’t be perfect. Even better if you measure let’s say 3 layers (sponge only) on top of each other. -2mm is a little too thin not to be effected by compression.

And you shouldn’t push super hard, just firm.

Cheers
L-zr

 

[lodro]

Even better if you measure let’s say 3 layers (sponge only) on top of each other. -2mm is a little too thin not to be effected by compression

BB would disagree, I do too 😁

 

[brokenball]

The ignorance of this forum and what passes for knowledge amazes me.
If the foam rubber/sponge was cut in a big sheet that you could sleep on, would you rather it be 1mm, 2mm, 5mm or 100mm thick? 100mm would be more comfortable.

If you had to fall on concrete over with news paper, how many sheets of newspaper would you like to have between you and the concrete?

THICKER IS SOFTER.
I have criticized the Paddle Palace's data because 1.8mm 2.0mm and 2.2mm rubbers will have different hardness. The 2.2mm sponge will feel softer.

One should study this before making any more stupid statements.

Series and parallel springs - Wikipedia

en.wikipedia.org

Also, the hardness of the top sheet is the most important factor. If the topsheet if relatively hard, thick or stiff, it will distribute the force of the little pin over more area making making the reading higher yet. Distributing force over more area is like have more springs in parallel.

There is too much emphasis on hardness. There is too hard and too soft and we are like Goldilocks and prefer something in between. There are no calculation you can do with a durometer reading. Durometer readings have no units unlike a spring constant. In industry we have used durometer reading for checking the hardness/durability of conveyor belts. The conveyor belts are made of one type of rubber. Using a durometer for measuring the hardness of a TT rubber is a misapplication because TT rubbers have a separate top sheet and a sponge.

I should be paid for teaching physics.

 

[IB66]

The whole hardness (of sponge) issue is that different scales are used shore a, asker that etc etc,
When testing at home many differing results occur, and generally, testing of both sponge and top sheet together are measured.
I think somewhere in the threads I read that a min thickness of 5 to 6 mm is required (ideally), so measuring a sponge (alone) at 2.1mm thick leaves a 'false' impression (see what I've done there??!!!)
A durometer needle is pointless (see what I've done there??!!!)
Even using a flat plate , although it may be better than a needle is not ideal.
Maybe a durometer with a TT ball shaped plate, that compresses into the sponge would be better, at least it would give a result based on what a TT ball does at impact (although a TT ball may deform slightly on impact).

 

[zeio]

The whole hardness (of sponge) issue is that different scales are used shore a, asker that etc etc,
When testing at home many differing results occur, and generally, testing of both sponge and top sheet together are measured.
I think somewhere in the threads I read that a min thickness of 5 to 6 mm is required (ideally), so measuring a sponge (alone) at 2.1mm thick leaves a 'false' impression (see what I've done there??!!!)
A durometer needle is pointless (see what I've done there??!!!)
Even using a flat plate , although it may be better than a needle is not ideal.
Maybe a durometer with a TT ball shaped plate, that compresses into the sponge would be better, at least it would give a result based on what a TT ball does at impact (although a TT ball may deform slightly on impact).

Sadly no, you are comparing a solid metal ball with a hollow plastic ball (different brands have different hardness, too).

What folks have to understand here is that there are multiple hardness standards out there, some of which are interchangeable/compatible. What some of us are attempting here is:
1. To figure out which specific standards are used by which manufacturers/brands here, and ideally how they make the measurement;
2. We hope to be able to reproduce it and make the same measurement with the most commonly used hardness scales;
3. We hope to be able to compare across different manufacturers/brands with a certain level of confidence.

Over the years, the last point has been attempted by various folks/magazines. It won't represent real-world scenario, but we don't care about feel either, which is subjective (whatever feels good for you is not the concern here). We want to leave that out of the equation. We want a simple number that scales linearly that can be compared quickly, which is exactly what a hardness scale does.

 

[zeio]

The ignorance of this forum and what passes for knowledge amazes me.

...

THICKER IS SOFTER.
I have criticized the Paddle Palace's data because 1.8mm 2.0mm and 2.2mm rubbers will have different hardness. The 2.2mm sponge will feel softer.

Hardheaded engineer happens to be half right and half ignorant this time, as in 2011. As with the COR for softer/harder thinner/thicker rubbers, I've seen conflicting results on this.

Data collected by ivictor and posted by JimT.

http://mytabletennis.net/forum/foru...9&title=hardness-table-topsheet-sponge#488469

Disclaimer: the following numbers are obtained by using ShoreA scale on a regular durometer (the one which is not geared toward measuring rubbers and sponge) from our fellow forum member ivictor - he tests the rubber in several places (both sides, topsheet and sponge) and then averages it. Some numbers (like Palio Blitz or PME, for instance) are also averaged over more than one rubber. Whenever the thickness is not stated explicitly, it's MAX.

Brand	Rubber	Topsheet	Sponge
LKT	Rapid Speed 2.2	30	29
LKT	Rapid Speed 2.0	27	28
Palio	Macro Era 2.0	26	28
Palio	Macro Era 2.2	28	31

 

[Trevize84]

But now I finally got my own shore O durometer and can finally find out the truth.

If I firmly press with medium pressure, it reads 45. If I push hard, it reads about 47. and if I put all my strength into it, it hits 50.

And the truth is... nobody knows how hard rubbers are, numbers are random! 🤣🤣🤣

 

[jbvttcc]

Can't do Arthur China yet because I haven't opened the seal. But eventually will get to it.

On another note, I actually don't know how to use the Durometer. How hard am I supposed to push on it? The harder I push, the harder it reads.

It didn’t come with instructions?

 

[TensorBackhand]

And the truth is... nobody knows how hard rubbers are, numbers are random! 🤣🤣🤣

Well it is very difficult to get a precise measure with my little tool here. Because the reading varies wildly based on how hard I push. But between 2 rubbers, you can generally tell which one is harder. Because for example, if you try to get both to get 55d on the durometer, you may need to noticeably push harder on one rubber over the other.

 

[turbozed]

When I get back to Vietnam, I'm going to have to make a video showing the consistency of my durometer.

Feels like everyone else got a dud durometer that has crazy inconsistent readings but me.

 

[NextLevel]

When I get back to Vietnam, I'm going to have to make a video showing the consistency of my durometer.

Feels like everyone else got a dud durometer that has crazy inconsistent readings but me.

Which one did you get and where did you get it from? In case I get bored...

 

[lodro]

Well it is very difficult to get a precise measure with my little tool here. Because the reading varies wildly based on how hard I push. But between 2 rubbers, you can generally tell which one is harder. Because for example, if you try to get both to get 55d on the durometer, you may need to noticeably push harder on one rubber over the other.

This is getting effen ridiculous. Why do you think you have to press down at all ?
Just place the darn gadget on the sponge and gently press until the flat foot is in full contact with the rubber. Don't press the foot into the rubber.
And don't ignore that you bought the wrong one, On the dial it reads TYPE O but you should have the type A """"""Type A is suitable for general rubber, synthetic rubber, soft rubber, poly fat, leather, wax etc. """"""

 

[TensorBackhand]

It didn’t come with instructions?

mine didn't, but some other forum guys said theirs came with instruction.

This is getting effen ridiculous. Why do you think you have to press down at all ?
Just place the darn gadget on the sponge and gently press until the flat foot is in full contact with the rubber. Don't press the foot into the rubber

This doesnt work. When i do that, the readings give absurdly low measrues like 35 or 40.

 

[lodro]

mine didn't, but some other forum guys said theirs came with instruction.

This doesnt work. When i do that, the readings give absurdly low measrues like 35 or 40.

It give absurdly low measures because YOU BOUGHT TYPE O