|
|
Why do Rubbers Click? |
Post Reply | Page 12> |
Author | |||
racquetsforsale
Gold Member Joined: 10/02/2010 Location: at the table Status: Offline Points: 1268 |
Post Options
Thanks(0)
Posted: 03/03/2011 at 10:22pm |
||
Please enlighten me regarding the following:
Thanks. |
|||
Sponsored Links | |||
pnachtwey
Platinum Member Joined: 03/09/2010 Location: Vancouver, WA Status: Offline Points: 2035 |
Post Options
Thanks(0)
|
||
My H2 Neo doesn't click 'un tuned'. I have no plans to 'tune' it to see if it clicks when tuned.
The noise doesn't get the ball on the table. None of my rubbers 'click' but my 729 Bomb does make a distinctive 'corky' higher pitched sound. Perhaps that is due to the cork in the paddle , not the rubber. I don't see why the sound is so important. It is how the rubber plays that counts. T05 plays well with out the click. Sound maybe the by product of some good playing rubbers but it is not the cause of why the rubbers play well. |
|||
bluebucket
Platinum Member Joined: 02/20/2011 Location: 16 Status: Offline Points: 2882 |
Post Options
Thanks(0)
|
||
I'm sure the infamous sound comes from nothing more than hitting something that's under pressure and having it return to shape, if you have enough pressure on a sponge and top sheet it'll make a sound when you hit it hard enough in the right direction. ESN Tensors.. are the sponges really under tension.. well no, but they have certainly the most elastic top sheets in the business and to go with it they loose elasticity the quickest, that's just how the planet works. The top sheet maybe under some slight tension against the sponge but I believe the click the softer tensors make is just coming from the topsheet flicking back into shape. CJ8000 2-wing looper is a dead sponge even when new and shrinks a lot with age. I have a old sheet and it's rolled up inversely all by itself, it never made any sound and it wasn't much of a rubber anyway. Hurricanes click with heavy handed doses of speed glue. A hard sponge that's been put under pressure from expansion versus the top sheet will always have more rebound (so more spin and speed) than a soft sponge that's under no pressure, much more. Go back to balloons for a moment. If you jump on a giant balloon with say 0 psi in it nothing will happen, but it you fill it with 20 psi and jump on it the rebound might be impressive enough to make you knee yourself in the face and knock your front teeth out. This is the same deal with speed glue, think of a sponge as an amount of air, which is basically what it is. Stretching it allows the top sheet to become loaded under pressure and is pretty much just a trampoline 2.2mm above the blade with air under it. Also because they are measuring top sheets for stretch now the amount of pressure you can load up on a sponge is more limited than it used to be. So I think you will be able to get more extra power from a rubber that has a stiffer top sheet, ie. you wouldn't be able to tune an ESN tensor much at all before the top sheet stretched huge amounts, which is probably why they go off the rails when you try and even then because the sheet isn't resisting the sponge the sponge wont have loaded up the sheet as much, still when it comes to playing without bending the rules they are probably the best performing rubbers these days because of the better elasticity combined with the porous sponge. It all adds up to Chinese rubbers and Tenergy (which no matter what anybody says seems to be especially made for bending(cheating) with the current rules with a super absorbent sponge + firm very grippy top sheet) I think you will find that most of the real fanatical Tenergy freaks are either boosting them, still using VOC glues or just flat out imagining most of the performance. If you could get rid of tuning all together then you would see the softer sheets being more popular with pros, until then, harder is better and your stiff Chinese tackies and Tenergy will still be the best rubbers for playing/tuning/cheating :D. Also I will add none of this may be actual fact but it's how I rationalise what's going on in the world and it makes sense to me :) Edited by bluebucket - 03/04/2011 at 12:17am |
|||
roundrobin
Premier Member Joined: 10/02/2008 Location: United States Status: Offline Points: 4708 |
Post Options
Thanks(0)
|
||
Rubbers click loudest if the topsheet is stretched tight like a drum, and the sponge is soft and airy (or gassy, lol). So the more elastic the topsheet and the softer the sponge, the louder the click sound will be if it's stretched tightly when glued on the blade. Essentially your setup will become a percussion instrument. |
|||
racquetsforsale
Gold Member Joined: 10/02/2010 Location: at the table Status: Offline Points: 1268 |
Post Options
Thanks(0)
|
||
Thanks for the response, guys.
Sorry your CJ8000 didn't work out for you, bluebucket. Unless Palio's improved the quality of the rubber since you purchased it, I guess my sheet will meet the same end. Although I think it's actually a pretty good rubber. There's not much bounce just bouncing the ball on it, but when actually hitting and looping with it, it feels quite good. Lots of spin and good control on all shots, except when counterlooping---you either have to swing fast or slow to keep the ball on the table, or really close the racket face to compensate for the generous throw; any swing speed between fast and slow just sends the ball long. Strange. I think a 2.0 version would be a lot better. I also forgot to mention in the OP. Both the Palio rubbers are emitting an ammonia like odor. Is it from some tuning agent? Could it be harmful? I could really smell it after storing the rubbers in a drawer. |
|||
Imago
Premier Member Joined: 07/19/2009 Location: Sofia Status: Offline Points: 5897 |
Post Options
Thanks(0)
|
||
Click is good, plyack is bad. Fact is that Chinese rubbers plyack more often than euro or jap rubbers. |
|||
razortt
Silver Member Joined: 07/09/2008 Location: United States Status: Offline Points: 504 |
Post Options
Thanks(0)
|
||
Wow, very nice explanation! Good job! |
|||
APW46
Assistant Moderator Joined: 02/02/2009 Location: United Kingdom Status: Offline Points: 3331 |
Post Options
Thanks(0)
|
||
The noise you hear when a ball is struck by a glued up rubber is infact two noises in quick succession which gives the familiar 'tock' sound. The Voc (volatile organic compounds) in the glue diffuse into the cells of sponge when vulcanising glue is applied to a rubber. The cell walls expand under pressure becoming thinner and making the sponge softer yet more tensile. When a ball hits the rubber with moderate to high velocity, the already under pressure gasses contained within the cells directly where the ball strikes, become under so much pressure that they momentarily liquify, causing an implosion (the first noise) as the ball sinks into the sponge further than it would without glue. After the ball either 'bottoms out' or reaches the point where the elasticity of the sponge will allow no more distortion, the ball starts to leave the sponge causing instant negative pressure in the sponge cells which at this point still contain liquified gasses. The pressure is no longer high enough to contain the Voc's in liquid form and they explode back into gas (the second noise) and in doing so, give the ball the extra catapult effect that we associate with speedglue. I'm not so sure why the modern speedglue effect rubbers make the same noise, but i would guess the gas trapped within the sponge cells mimicks the VOC effect. |
|||
The Older I get, The better I was.
|
|||
stoic
Super Member Joined: 02/10/2009 Location: United Kingdom Status: Offline Points: 141 |
Post Options
Thanks(0)
|
||
Interesting answer APW which makes a lot of sense. The harder the ball is hit, the more the gases liquify, the louder the click sound.
I will be listening out for the 2 sounds, never noticed that before!
|
|||
http://www.static-sounds.com
Check out our tunes! |
|||
TheRobot99
Silver Member Joined: 10/21/2010 Location: USA Status: Offline Points: 915 |
Post Options
Thanks(0)
|
||
As a chemical engineering student, I liked that APW.
|
|||
Ross Leidy Custom, DHS Hurricane III Neos, Nittaku Nodias
Xiom Fuga, Globe 999 National 39, Nittaku Nodias JOOLA Torre All+, DHS Hurricane II #19 Sponge, Galaxy Moon 38 PTTC VP - 2011-12 |
|||
racquetsforsale
Gold Member Joined: 10/02/2010 Location: at the table Status: Offline Points: 1268 |
Post Options
Thanks(0)
|
||
APW46, If the VOC can diffuse into the sponge cells, then it can also leave the cells, which is what has happened when the speed glue effect wears off, right? So what keeps the VOC trapped inside the cells for the time being, especially when it's under pressure from ball contact? Does the sponge need to have a closed-cell structure for speed glue to work? Wow, never in my wildest imagination would I have guessed phase changes are taking place in the sponge. There should be a science TV show about this topic. Thanks. |
|||
pnachtwey
Platinum Member Joined: 03/09/2010 Location: Vancouver, WA Status: Offline Points: 2035 |
Post Options
Thanks(0)
|
||
I am skeptical too but I doubt any gas can escape fast enough.
Good question and if so then how does the VOC get into the closed cells?
I never would have guessed either and don't believe it. Oxygen and Nitrogen must be cooled also to get it to liquefy. Water and oil cavitate when there is a vacuum and the fluid essentially boils at a low pressure and when pressure increases the bubbles collapse. This is the opposite process mentioned in the link. Cavitation also destroys propellers and pumps. I wonders would it would do to much more fragile sponge. I would want to see a link to data that shows what gas is being compressed and how it is turned into a liquid. A refrigeration cycle has freon or ammonia being compressed as a gas but then it must be cooled to remove the heat before the gas turns into a liquid. HOW IS THE HEAT REMOVED FROM THE PADDLE ? Where is the energy sink? A refrigerator has a heat exchanger. I am very skeptical. Obviously something is happening to make the click but I seriously doubt the cavitation explanation is it. Edited by pnachtwey - 03/04/2011 at 6:17pm |
|||
APW46
Assistant Moderator Joined: 02/02/2009 Location: United Kingdom Status: Offline Points: 3331 |
Post Options
Thanks(0)
|
||
A bit like a bouncy castle kids inflatable is fed by an air compressor, when the compressor is switched off, the bouncy castle goes down, when the VOC's are spent, the sponge cells deflate and the glue effect wears off.
|
|||
The Older I get, The better I was.
|
|||
racquetsforsale
Gold Member Joined: 10/02/2010 Location: at the table Status: Offline Points: 1268 |
Post Options
Thanks(0)
|
||
Say, could the VOC smell like ammonia, because that's how my rubbers smell at the moment.
|
|||
racquetsforsale
Gold Member Joined: 10/02/2010 Location: at the table Status: Offline Points: 1268 |
Post Options
Thanks(0)
|
||
Actually, a combination of ammonia and very heavily fragranced soap.
|
|||
APW46
Assistant Moderator Joined: 02/02/2009 Location: United Kingdom Status: Offline Points: 3331 |
Post Options
Thanks(0)
|
||
VOC gas smells like glue.
|
|||
The Older I get, The better I was.
|
|||
ZingyDNA
Platinum Member Joined: 09/19/2008 Status: Offline Points: 2373 |
Post Options
Thanks(0)
|
||
Many Chinese rubbers after 2008 claim to have built-in glue effect -- They don't. They just have more lively sponges than before.
|
|||
APW46
Assistant Moderator Joined: 02/02/2009 Location: United Kingdom Status: Offline Points: 3331 |
Post Options
Thanks(0)
|
||
|
|||
The Older I get, The better I was.
|
|||
racquetsforsale
Gold Member Joined: 10/02/2010 Location: at the table Status: Offline Points: 1268 |
Post Options
Thanks(0)
|
||
Crap. Then that's what it is, kinda sour, like Elmer's glue.
Heads up, folks: Palio CJ8000 2-wing-loop and HK1997 biotech (grippy/non-tacky) have VOCs.
|
|||
APW46
Assistant Moderator Joined: 02/02/2009 Location: United Kingdom Status: Offline Points: 3331 |
Post Options
Thanks(0)
|
||
|
|||
The Older I get, The better I was.
|
|||
TheRobot99
Silver Member Joined: 10/21/2010 Location: USA Status: Offline Points: 915 |
Post Options
Thanks(0)
|
||
I don't think he was calling what you said "crap." I think it was just an exclamation. I could be wrong though... |
|||
Ross Leidy Custom, DHS Hurricane III Neos, Nittaku Nodias
Xiom Fuga, Globe 999 National 39, Nittaku Nodias JOOLA Torre All+, DHS Hurricane II #19 Sponge, Galaxy Moon 38 PTTC VP - 2011-12 |
|||
racquetsforsale
Gold Member Joined: 10/02/2010 Location: at the table Status: Offline Points: 1268 |
Post Options
Thanks(0)
|
||
APW46, No offense meant. Please do read my posts carefully and in context of our previous correspondence.
The premise of our previous discussion is I do not know whether my rubbers have VOCs but I do know they smell.
I mentioned an ammonia-like smell and deferred to your experience and expertise. You answered my question, thank you, saying that VOCs smell just like glue.
Well Elmer's glue, to me, smells sour; and ammonia, to me, also smells sour. So, "CRAP!" my rubbers are likely to have harmful VOCs.
I even gave a heads up to others that those 2 particular Palio rubbers have VOCs.
How can you possibly misinterpret the intent of my comments?
|
|||
mmerkel
Silver Member Joined: 01/02/2010 Location: Canada Status: Offline Points: 746 |
Post Options
Thanks(0)
|
||
I don't think ammonia qualifies as a VOC in this instance. Almost all of the (legal) water based glues I tried and have seen have ammonia as a solvent.
|
|||
#1 RL Balance -Bluefire M2 -Acuda S2
#2 RL Avalanche#2 -Bluefire M2 -Sigma Europe #3 Primorac -Boost TP -Magna TC |
|||
pnachtwey
Platinum Member Joined: 03/09/2010 Location: Vancouver, WA Status: Offline Points: 2035 |
Post Options
Thanks(0)
|
||
The fact that you can smell ammonia means that it is volatile as in it will readlily evaporate into a gaseous form for your nose to detect. When I use it to clean my greasy stove my whole house smells like ammonia for a while. I haven't smelled any rubbers that smell like ammonia though.
|
|||
racquetsforsale
Gold Member Joined: 10/02/2010 Location: at the table Status: Offline Points: 1268 |
Post Options
Thanks(0)
|
||
mmerkel, I don't know if it is really ammonium. It smells like ammonium to me, sharp and a bit sour. If it is indeed ammonium, then I guess I have nothing to worry about, but if it is actually VOCs as APW46 explained, I gonna have to leave the racket out in the open.
That or hold my breath every time I take it out of storage. Edited by racquetsforsale - 03/05/2011 at 12:46am |
|||
stiltt
Assistant Admin Joined: 07/15/2007 Location: Location Status: Offline Points: 984 |
Post Options
Thanks(0)
|
||
+1.
It's so hard to find the right analogy to explain with simple words ideas that are very complex. RR did it again.
|
|||
stiltt
Assistant Admin Joined: 07/15/2007 Location: Location Status: Offline Points: 984 |
Post Options
Thanks(0)
|
||
Also read this:
The cavitation part of the article is fascinating. Search for "H. Cavitation and Water Hammer Effects" on that page.
|
|||
APW46
Assistant Moderator Joined: 02/02/2009 Location: United Kingdom Status: Offline Points: 3331 |
Post Options
Thanks(0)
|
||
|
|||
The Older I get, The better I was.
|
|||
racquetsforsale
Gold Member Joined: 10/02/2010 Location: at the table Status: Offline Points: 1268 |
Post Options
Thanks(0)
|
||
no harm done.
|
|||
aeoliah
Premier Member Joined: 11/18/2005 Location: Indonesia Status: Offline Points: 3215 |
Post Options
Thanks(0)
|
||
We are from many different countries, and very likely English is not our mother tongue, so there are chances that we either misintepret something or we do not understand some joke. It happens to me many times
|
|||
Member of the Single Ply Hinoki Club
Viscaria Super ALC C-Pen Rasanter C48 |
|||
Post Reply | Page 12> |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |
Forum Home | Go to the Forums | Forum Help | Disclaimer
MyTableTennis.NET is the trading name of Alex Table Tennis Ltd. |