|
|
Expressing relative blade speed |
Post Reply | Page <1234> |
Author | ||
berndt_mann
Gold Member Joined: 02/02/2015 Location: Tucson, Arizona Status: Offline Points: 1719 |
Post Options
Thanks(0)
|
|
I still retain some knowledge about music theory, though its been 52 years since I last studied music theory at the Cleveland, Ohio Institute of Music. It never occurred to me, however, or any other table tennis player I knew to try to measure the amplitude or frequency peaks of any of the blades I used while also studying classical defensive table tennis theory under six-time Ohio State Champion and two-time National Doubles Champion Danny Vegh. Now, however, my curiousity has been piqued. I'm wondering what the scale (modal, pentatonic, hexatonic, microtonal) might have been for the American birch/basswood/birch 3-play Hock No. 74 blade I played with affixed with British Leyland hard rubber for most of my training or the Cor DuBuy red oak/European birch/red oak Loop Drive blade affixed with Butterfly
D-13 sandwich sponge inverted rubber that I took along with me as well as the Hock when I enlisted in the Army. Polytonality, perhaps between the two? Twelve-tone serialism? A pity I shall never know.
Edited by berndt_mann - 06/30/2017 at 6:33pm |
||
bmann1942
Setup: Mark Bellamy Master Craftsman blade, British Leyland hard rubber |
||
Sponsored Links | ||
arg0
Platinum Member Joined: 07/22/2009 Location: Germany Status: Offline Points: 2023 |
Post Options
Thanks(0)
|
|
I suspect recording and spectrum analysis equipment was less readily available, then. Studying mechanical response of the blades is interesting to some. Does it make you a better player? No. Does it give you at least one objective criterion to assess blade characteristics? Yes. |
||
slevin
Premier Member Joined: 03/15/2012 Location: USA Status: Offline Points: 3602 |
Post Options
Thanks(0)
|
|
Cool, arg0's done this before!
Garaydia ZLC (85g): 1830 So far, very true to expectations.
|
||
Trade feedback:
http://mytabletennis.net/forum/forum_posts.asp?TID=50787 |
||
Baal
Forum Moderator Joined: 01/21/2010 Location: unknown Status: Offline Points: 14336 |
Post Options
Thanks(0)
|
|
It's not just weight though. I have two Viscaias of the same weight that have a different tone when I knock them against my head, and it would certainly show up on this measurement. And yes, the one with a higher pitched tone is faster |
||
Baal
Forum Moderator Joined: 01/21/2010 Location: unknown Status: Offline Points: 14336 |
Post Options
Thanks(0)
|
|
Very good point. |
||
Baal
Forum Moderator Joined: 01/21/2010 Location: unknown Status: Offline Points: 14336 |
Post Options
Thanks(0)
|
|
Including the range of mechanical responsex seen for different samples of a particular type of blade. |
||
zeio
Premier Member Joined: 03/25/2010 Status: Offline Points: 10833 |
Post Options
Thanks(0)
|
|
Other than the speed, the mode of vibration can reveal a lot about a blade.
The 1st bending mode is usually within the first few hundred Hz, lower for a clamped blade, and higher for a freely-suspended blade, with the real-world grip resembling the latter, but with higher damping. The 1st torsional mode follows closely. The 2nd bending mode comes next, and so on. The membrane mode doesn't come in until much later. The 1st bending mode contributes the most to dwell/feel as the handle vibrates the most at that frequency. That mode is also related to the sweet spot as one node(least vibration) is somewhere in the upper center of the blade head and another node where the handle meets the blade head. The 1st torsional mode gets agitated the most when the racket is hit off-centered. As the mode goes higher, the role it has in the racket-ball interaction diminishes. Looking at the data, it looks like the mic is picking up the membrane mode the most, which contributes the most to the sound of the blade. Edited by zeio - 06/30/2017 at 8:47pm |
||
Viscaria FL - 91g
+ Neo H3 2.15 Blk - 44.5g(55.3g uncut bare) + Hexer HD 2.1 Red - 49.3g(68.5g 〃 〃) = 184.8g |
||
BigFatLoop
Member Joined: 05/06/2017 Location: Milky Way Status: Offline Points: 82 |
Post Options
Thanks(0)
|
|
Sure, yeah!! ... I agree with everything you just said so please put me down as the co-author. Thanks!
Edited by BigFatLoop - 06/30/2017 at 8:56pm |
||
berndt_mann
Gold Member Joined: 02/02/2015 Location: Tucson, Arizona Status: Offline Points: 1719 |
Post Options
Thanks(0)
|
|
Holy crap! Blade amplitude theory is a lot more complicated than Werner Von Braun rocket science.
What ever happened to a good old simple game of ping pong? Damn. Do y'all take along an IBM Watson to make sure that the physics, acoustics, chemistry, and even meteorology are just right for your respective styles before contemplating entering the U-1800 event at the Whistlestop, Wyoming come one come all two-star invitational (free chocolate chip cookies, homemade lemonade, and you get to ride a Mustang [a real one, not the car])? (Lots of involuntary head shaking from your no longer fearless author) Edited by berndt_mann - 06/30/2017 at 9:30pm |
||
bmann1942
Setup: Mark Bellamy Master Craftsman blade, British Leyland hard rubber |
||
Baal
Forum Moderator Joined: 01/21/2010 Location: unknown Status: Offline Points: 14336 |
Post Options
Thanks(0)
|
|
At some point I predict people will be providing this number for blades they sell here.
I think this will be really useful for comparisons within a blade class-- comparisons of one all wood to another, or comparing two different ALC/ZLC blades. Zeio is right to remind us that how or if the blade is secured will potentially affect tbe result. |
||
h0n1g
Silver Member Joined: 05/03/2005 Location: CA Status: Offline Points: 839 |
Post Options
Thanks(0)
|
|
Agree with what Baal says, i think it is an excellent indicator. Is it the final truth? No, but I think it will provide people with a better idea of what sort of "speed" they are actually after.
|
||
Baal
Forum Moderator Joined: 01/21/2010 Location: unknown Status: Offline Points: 14336 |
Post Options
Thanks(0)
|
|
IMHO certainly better than anything we have had before. Especially given that the apps are free.
Congratulations to those of you who independently came up with this. One thing that occurs to me to add. I have about nine or so Viscarias, but one is amazingly better than all the others to play with. It is the best blade I have ever played with and I am really lucky to have it (I bought it here by the way). It is not just the weight, and it is not just the pitch when I knock it against my head. I have a couple of other blades that are similar in terms of weight and pitch (although a lot of them have a higher pitch and don't feel anywhere close to as good). Somehow this blade's sound seems to be a lot more "pure" and seems to resonate longer. Next time I change the rubber I will get this app and compare it to some of its lesser brethren to see if some difference shows up in its spectrum (I expect this would show up in the higher components of the spectrum). Might be awhile though, the rubber that is on it refuses to die and is playing great right now, so I don't want to mess with anything. It may depend a lot on how good the pickups are in my phone. |
||
h0n1g
Silver Member Joined: 05/03/2005 Location: CA Status: Offline Points: 839 |
Post Options
Thanks(0)
|
|
I've added all submissions to the sheet I posted.
Also added two of my blades: Timo Boll ALC and Apolonia ZLC Edited by h0n1g - 07/01/2017 at 8:59pm |
||
h0n1g
Silver Member Joined: 05/03/2005 Location: CA Status: Offline Points: 839 |
Post Options
Thanks(0)
|
|
I've also added arg0's list to the sheet
|
||
Magic_M
Platinum Member Joined: 05/31/2012 Location: Germany Status: Offline Points: 2220 |
Post Options
Thanks(0)
|
|
Sorry guys, I really like the idea, but some of the results have nothing to do with my former impressions.
Do you really think or believe, that a WSC and PPA are faster than a PPP ? Does it sound realistic, that a low weight P500 (80g) is as fast as a 91g Tenor or as a Clipper Wood? OTC is as fast as Boll ZLC and faster than Mizutani? Maze and KSL are also faster than Mizutani? For me the OTC is slower than Boll ALC and Mizutani is as fast as Boll ZLC. I don`t know the reasons (different kind of balls, different distance form ball to smartphone, different hight, different kind of bouncing, ....), but fact is, that a buyer will be extremely surprised if he relied on these results. I would like to see his eyes, if he is playing an OTC now and is looking for something slower. So he looks in this docsheet and decides to buy the "slower" Mizutani ZLC. Another one plays the Tenor and wants something lighter, but as fast and decides to buy a P500. I am sure, both will have "interesting" results in their next training-session. Once again: the idea is really great, but the test-conditions have to be as equal as possible. Otherwise the results are not worth anything.
|
||
slevin
Premier Member Joined: 03/15/2012 Location: USA Status: Offline Points: 3602 |
Post Options
Thanks(0)
|
|
Re: Magic_M's concerns:
|
||
Trade feedback:
http://mytabletennis.net/forum/forum_posts.asp?TID=50787 |
||
Hozuki
Super Member Joined: 01/22/2017 Location: Germany Status: Offline Points: 477 |
Post Options
Thanks(0)
|
|
I know why the measurements are faulty.
First of all, impact strenght or ball type or height does not matter. Secondly, a blade does not have a single pitch. It has multiple pitches. The ones that are most dominant are the prime, third and fifth of the underlying scale. And that's why there is confusion here, as nobody bothers to identify the prime of the scale. Instead ppl would measure either one of those three dominant tones, yielding a variation of up to half an octave, or 1.5 times the frequency. For example, arg0 measured the OC with 1100 Hz (fifth = C#), while I knew that the prime is F# from my own spectal analysis, so I posted 1400 Hz instead. And surely, somebody would happen to measure the third (A# = 932 Hz), since it is quite dominant as well. I argue that measuring the prime instead of randomly measuring the 3rd or 5th instead will yield much more reliable data. |
||
arg0
Platinum Member Joined: 07/22/2009 Location: Germany Status: Offline Points: 2023 |
Post Options
Thanks(0)
|
|
Yes, the highest peak in the audio spectrum is typically the frequency of the membrane mode. Sound amplitudes at lower frequencies are normally deadened by the hand holding the blade. |
||
arg0
Platinum Member Joined: 07/22/2009 Location: Germany Status: Offline Points: 2023 |
Post Options
Thanks(0)
|
|
The frequency of the highest peak does not vary much under different test conditions. But it is not directly related to speed, not even when taking weight into account. |
||
arg0
Platinum Member Joined: 07/22/2009 Location: Germany Status: Offline Points: 2023 |
Post Options
Thanks(0)
|
|
Some theory of blade mechanics with some great illustrative images are in this thread
http://mytabletennis.net/forum/forum_posts.asp?TID=60725 Where's John Staley, aka JRSDallas? We miss you! I wonder whether he further elaborated on/published his theory. More recent scientific articles exploring the relationship between blade mechanics and acoustics http://www.sciencedirect.com/science/article/pii/S1877705814005840 http://www.sciencedirect.com/science/article/pii/S1877705812017316 Edited by arg0 - 10/27/2017 at 4:03pm |
||
Baal
Forum Moderator Joined: 01/21/2010 Location: unknown Status: Offline Points: 14336 |
Post Options
Thanks(0)
|
|
There is a really cool animation here, int this case of a circular membrane under tension, but still really interesting.
http://www.acs.psu.edu/drussell/Demos/MembraneCircle/Circle.html |
||
h0n1g
Silver Member Joined: 05/03/2005 Location: CA Status: Offline Points: 839 |
Post Options
Thanks(0)
|
|
I don't think the distance to the blade has a direct effect on frequency unless you are recording multiple meters away and with objects blocking the sound path. I've recorded mine about 10-15cm away from the phone.
Again I think we can't expect laboratory conditions and results but I still think this gives a good indication of what kind of speed to expect. |
||
arg0
Platinum Member Joined: 07/22/2009 Location: Germany Status: Offline Points: 2023 |
Post Options
Thanks(0)
|
|
BTW, the frequencies below about 1000 Hz are deadened/absorbed by the player's hand only if the blade is gripped tightly.
When recording the sound, I normally tend to lay the blade flat between two fingers (see picture; and no, the picture is deceiving: my index finger touches only the handle), so that the grip force is minimal and few vibrations are absorbed by my hand. |
||
arg0
Platinum Member Joined: 07/22/2009 Location: Germany Status: Offline Points: 2023 |
Post Options
Thanks(0)
|
|
The animation is cool, but this is not how a table tennis blade vibrates. In the circular membrane animation the whole outer perimeter is fixed. In a blade, the only relatively fixed part of the blade face is where it meets the handle. |
||
apodra74
Beginner Joined: 02/22/2017 Location: Greece Status: Offline Points: 12 |
Post Options
Thanks(0)
|
|
I tested my blades again today what I noticed that can make your measurements go all over the place is if you hold the blade lightly or really tight.
Btw I tried with Donic ball p40+ and with a Nittaku Premium 40+ similar results with both balls loose grip, the blades I tested: Stiga Ulf Tickan Carrlson allround AN 82gr (30 years old) = 1184 Donic Ovtcharov Carbospeed FL 88gr = 1674 Butterfly Schlager Carbon ST 95gr = 1943 Butterfly Schlager Carbon FL 100gr = 1948 Xiom Axelo FL 87 gr. = 1981 Edited by apodra74 - 07/01/2017 at 5:04pm |
||
h0n1g
Silver Member Joined: 05/03/2005 Location: CA Status: Offline Points: 839 |
Post Options
Thanks(0)
|
|
Added to the list. Just by looking at the numbers submitted from a number of different people, there is no doubt that this will be a decent indicator for blade speed.
|
||
arg0
Platinum Member Joined: 07/22/2009 Location: Germany Status: Offline Points: 2023 |
Post Options
Thanks(0)
|
|
Loose grip is key! also see my post above. |
||
NextLevel
Forum Moderator Joined: 12/15/2011 Location: Somewhere Good Status: Offline Points: 14845 |
Post Options
Thanks(0)
|
|
The most surprising thing I have seen so far is how far the Koto ALC blades are from blades like the Korbel or the KJH. I hope someone has put in an HL5 now.
This is great stuff and I commend slevin for getting this started. Over time, it is possible that frequency, top ply hardness, overall thickness. Handle dimensions etc. Might lead to an overall blade specification that predicts ahead of time whether someone will like a blade or not. |
||
I like putting heavy topspin on the ball...
Cybershape Carbon FH/BH: H3P 41D. Lumberjack TT, not for lovers of beautiful strokes. No time to train... |
||
NextLevel
Forum Moderator Joined: 12/15/2011 Location: Somewhere Good Status: Offline Points: 14845 |
Post Options
Thanks(0)
|
|
Hmmm... That looks different from what so remember and the Tour I had was faster than the Pro. But again, blades are blades. |
||
I like putting heavy topspin on the ball...
Cybershape Carbon FH/BH: H3P 41D. Lumberjack TT, not for lovers of beautiful strokes. No time to train... |
||
JacekGM
Platinum Member Joined: 02/17/2013 Location: USA Status: Offline Points: 2356 |
Post Options
Thanks(0)
|
|
This is all great, for some kind of blade comparison, especially after the method of measurement is somehow standardized. ... but guys, we play with RACKETS (blade + glue + rubber) NOT WITH BLADES . How a racket feels to me or "plays" will depend on so many other factors than just the vibration frequency of the blade.
Edited by JacekGM - 07/01/2017 at 7:55pm |
||
(1) Juic SBA (Fl, 85 g) with Bluefire JP3 (red max) on FH and 0.6 mm DR N Desperado on BH; (2) Yinhe T7 (Fl, 87 g) with Bluefire M3 (red 2.0) on FH and 0.6 mm 755 on BH.
|
||
Post Reply | Page <1234> |
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. |