Sponge Hardness new Video

[TensorBackhand]

This is interesting. The guy shows his hardness measurements. He shows D09c is 55d which is what we all expected. He shows G09c comes at 54d, which is surprising to me.

But what confuses me the most is that he shows H3 40 to measure at 58d. Based on most of the conversion charts that I have seen, I would have expected H3 40d to measure around 54d ESN.

So would H3 41 be like 60d ESN? I have a 41d H3 right now, but it doesn't seem insanely hard to me.

 

[PaddyPolar]

I did not know that G09c came in at 54 degrees. I have D09c and H3 and they fo seem similar, so your probably right that H3 is around 54 degrees. Maybe I should try out Glayzer and compare it to D09c and D05.

 

[TensorBackhand]

Has anybody else measured Chinese 40d or 41d to see what it really comes out to be on the ESN scale?

 

[IB66]

Butterfly website lists -
G09C as 42 degree
D09C as 44 degree

IF BTY and DHS use the same shore scale, which would be Shore A and ESN use Shore O scale

ROUGHLY,

G09C 42 degree Shore A = 54.6 degree Shore O
D09C 44 degree Shore A = 56.2 degree Shore O

H3 41 degree Shore A = 53.8 Shore O

Andro R48 is 48 degree shore O = 35 degree Shore A
Andro R53 is 53 degree shore O = 40 degree Shore A

Thats IF both BTY and DHS use the same scale. If either one of them uses ‘their own scale’ then I haven’t seen a chart that compares both Scales with each other.
There is a chart that compares the different Shore scales, but there are variations, you can’t say for sure that 1 degree on shore A scale = 1.2 degrees on Shore O scale, these last 2 figure are not precise at all, just used as an example.

 

[IB66]

Strangely, The Shore OO scale on the Shore scale comparison chart is for ‘sponge’ but it looks like it’s used to measure anything from a cushion to a tennis ball !!

Shore A - rubber, soft plastics and polyurethane
Shore O - soft rubber

I’ve never even checked out the Asker Scales!!!

Too many scales, maybe as part of registering rubbers on the LARC, ITTF should require that manufacturers state rubber / top sheet only hardness, sponge only hardness and combined hardness in a single stipulated scale!!!

What would we talk about??? 50% of posted threads would disappear!!!

 

[TensorBackhand]

How does the durometer measure hardness if the sponges are different thickness?

For example, if Dignics at 2.1mm measures 50d esn. Would the same Dignics at 1.9mm measure less than 50d?

 

[JJ Ng]

I don't know why would the sponge hardness matter. It also depends on the hardness of the topsheet.

It matters more about how you play with the rubber. I think of rubbers as soft, medium, and hard. I like my forehand to be hard with Chinese tacky rubber. I like my backhand to be soft tensor. I don't really care what degree of hardness it is.

 

[palguay]

In the beginning he mentions that the rating by rubber manufacturers says some number but you cannot verify, I actually did a test to get the effects of spin and speed on different rubbers so it is possible to get these numbers

 

[brokenball]

I don't know why would the sponge hardness matter. It also depends on the hardness of the topsheet.

You are correct. Hardness is a preference. It doesn't determine the ratio of tangential to normal COR

It matters more about how you play with the rubber. I think of rubbers as soft, medium, and hard. I like my forehand to be hard with Chinese tacky rubber. I like my backhand to be soft tensor. I don't really care what degree of hardness it is.

Yes, most things are a preference.

BTW, I support Palguay's research

 

[igorponger]

IMPERFECTION OF THE HARDNESS MEASUREMENT ON SANDWICH RUBBER SHEET. COMMON MISTAKE WITH NEWBIES.

The guy on present video did commit a faulty testing procedure, perhaps for not having engineering competence enough. You cant get an adequate measurement on those single rubber sheets, you need two or three sheets to form a multilayer cake. Testing on a single sheet will always give false results, somewhat greater numbers, because of the bottom stiffness. ASTM requires in lab tests the solid rubber sample to be 6 mm thick at minimum.

Be happy.

 

[Trevize84]

The guy measured glued rubbers god knows how many times and layers...

 

[igorponger]

IMPERFECTION OF THE HARDNESS MEASUREMENT ON SANDWICH RUBBER SHEET. COMMON MISTAKE WITH NOOBIES.

The guy on present video did commit a faulty testing procedure, perhaps for not having engineering competence enough. You cant get an adequate measurement on those single rubber sheets, you need two or three sheets to form a multilayer cake. Testing on a single sheet will always give false results, somewhat greater numbers, because of the bottom stiffness. ASTM requires in lab tests the solid rubber sample to be 6 mm thick at minimum.

Be happy.

Professional set of test instruments and materials.
Composite sandwich of two rubber sheets being tested, total thickness of 6 millimeters in accordance to ASTM D2240 standard procedure.

 

[7sagittarius7]

The guy measured glued rubbers god knows how many times and layers...

I mentioned in the video that the H3 was previously tuned, and that the D09c still has glue residue. The G09c was glued once with 2 layers of glue, and before measuring I removed the remaining glue. H3 is the Provincial version that was glued 2 times to the blade with 3 layers of glue and 2 layers of booster. Before the measurement, it sat in a drawer for 5 months, so the parts of the booster evaporated. The other 3 rubbers were new, taken out of the packaging.

The problem with this kind of manual measurement is that it depends on the pressure of the thumb on the top of the device. So, because of this, it is possible to get a variation of even up to 3-4 degrees. I tried to apply the same pressure with my thumb on all 6 rubbers, but the resistance provided by the soft tensor sponge and the hard DHS sponge are completely different, so it is possible that there are errors in the measurement.

 

[latej]

I don't know why would the sponge hardness matter. It also depends on the hardness of the topsheet.

It matters more about how you play with the rubber. I think of rubbers as soft, medium, and hard. I like my forehand to be hard with Chinese tacky rubber. I like my backhand to be soft tensor. I don't really care what degree of hardness it is.

You say you don't know why it matters, and in the next sentence you explain why it matters ;-)

 

[7sagittarius7]

This is interesting. The guy shows his hardness measurements.

Sorry for jumping into the discussion like that. Forgot to mention that I'm the guy in the video

What I wrote above is just additional info about measurement. The purpose of the video was more to explain the difference in sponge hardness, how it affects the game, measurement method and scales.

 

[SFF_lib]

This measurement returns the overall hardness of sponge AND topsheet.

If he compares two provincial rubbers - TG3 and H3 both blue sponge 40 degree, the TG3 will return a lower hardness due to softer topsheet.

 

[TensorBackhand]

Sorry for jumping into the discussion like that. Forgot to mention that I'm the guy in the video

What I wrote above is just additional info about measurement. The purpose of the video was more to explain the difference in sponge hardness, how it affects the game, measurement method and scales.

Hey! Great to see you here.

According to the conversion charts, H3 40 should be 54d on ESN scale. But when you measured it, it showed 58d after boosting. Why would it be so much harder than the conversion chart says?

 

[brokenball]

How does the durometer measure hardness if the sponges are different thickness?

For example, if Dignics at 2.1mm measures 50d esn. Would the same Dignics at 1.9mm measure less than 50d?

No one has answer this question. I know the hardness will change as thickness changes.

 

[Trevize84]

I mentioned in the video that the H3 was previously tuned, and that the D09c still has glue residue. The G09c was glued once with 2 layers of glue, and before measuring I removed the remaining glue. H3 is the Provincial version that was glued 2 times to the blade with 3 layers of glue and 2 layers of booster. Before the measurement, it sat in a drawer for 5 months, so the parts of the booster evaporated. The other 3 rubbers were new, taken out of the packaging.

The problem with this kind of manual measurement is that it depends on the pressure of the thumb on the top of the device. So, because of this, it is possible to get a variation of even up to 3-4 degrees. I tried to apply the same pressure with my thumb on all 6 rubbers, but the resistance provided by the soft tensor sponge and the hard DHS sponge are completely different, so it is possible that there are errors in the measurement.

Measuring a glued rubber isn't a bad idea. In the end the hardness you experience during gameplay is the one of the glued rubber. My comment was more related to the comparison people made between your measurements and data declared by the manufacturers.

 

[JJ Ng]

You say you don't know why it matters, and in the next sentence you explain why it matters ;-)

Sorry, I meant the exact degree of hardness. I go by roughly how it feels in my hand and on my blade