OOAK Table Tennis Forum

A standard steel plate is made of Steel S235 with a surface roughness of Ra <= 1.0 µm and Rmax <= 7.5 µm. The size is no smaller than 20mm thick and 200 x 200 mm large.

You may want to stick (fnarr, fnarr) with what the ITTF uses for its ball bounce test, as that would be in some way shape or form, comparable.

I think the old Konrad Tiefenbacher articles used a block of marble to test.

Imo there is no need for perfect 1. The ball itself will be the bottleneck at some point. A ball bounced in a 10mm hinoki blade is pretty much the same as that on a marble block.

Yep, considered that but getting a steel square 20cm by 20cm by 20cm today is not going to be practical.

Debater wrote:

Yes, but getting a steel cube 20cm by 20cm by 20 cm would be quite a bit more practical than what you have considered.

Don't thank me, pedantry, unlike table tennis prowess, can never be overrated.

On a more serious note, the COR of things like acrylic and even the previously mentioned steel are very much estimates, so however impractical the steel cube is, it is accepted by the ITTF to do things with.

What are the impracticalities involved with the steel?
Knowing how to get it? You have to use your block.
Cost? You'll just have to steel yourself for the price as it won't be a steal.
Secure storage? Everyone will want to steal it.
Humidity free storage? So it doesn't <NZ accent> rust </NZ accent> in piece(s)?

Very few suppliers in the UK with steel of the right type in that dimension and transport is a nightmare. Acrylic much easier to get.


Can you tell that no TT is having some affect?

Classical Golf is the only "ball & impactor" game to take the COR of the playing materials in serious manner.


https://www.youtube.com/watch?v=dOBmBfb-bz0

COR Stands for "coefficient-of-restitution"
http://www.golfclub-technology.com/coef ... ution.html
TAKE NOTE: It is impossible for the collision of your driver head and your golf ball to produce a perfectly elastic collision (COR of 1.000) in which all energy is transferred, for two reasons:
1.The clubface and the ball are made from completely different materials.
2. The clubhead and the ball are of two totally different weights.

You know, this doesn't really make sense to me. The article says that if e > 1 then the collision results in the release of energy (they give the example of nitrocellulose balls colliding and exploding..). But you find a LOT of materials with e > 1 (most elastomers, in fact). Take polycarbonate, for instance - e = 1.46. What does this mean? If you bounce a steel ball (e ~ 1) on a polycarbonate surface, does this mean that every bounce will be 46% higher than the previous bounce, and eventually it'll be bouncing itself into the stratosphere? Weird, no? If you bounce a polycarbonate ball on a polycarbonate surface, would it bounce (1.46^2 = 2.13) times (113%) higher each time?

Iskandar

You know, this doesn't really make sense to me. The article says that if e > 1 then the collision results in the release of energy (they give the example of nitrocellulose balls colliding and exploding..). But you find a LOT of materials with e > 1 (most elastomers, in fact). Take polycarbonate, for instance - e = 1.46. What does this mean? If you bounce a steel ball (e ~ 1) on a polycarbonate surface, does this mean that every bounce will be 46% higher than the previous bounce, and eventually it'll be bouncing itself into the stratosphere? Weird, no? If you bounce a polycarbonate ball on a polycarbonate surface, would it bounce (1.46^2 = 2.13) times (113%) higher each time?

Iskandar