Stringbed frequency to monitor string tension

[kwun]

here are my contribution:

racket, string, tension, frequency

NS9900 BG80 23 1046
ARC9 BG80 22 1016
Vapour Trail Tour ZM62 22 1137
AT700 BG80 26 1135
ARC10 ZM62 23.5 1171
ARC10 ZM62 21.5 1137
Trinity 2 BG85 21 1025
ARC7 Zymax 67 24 1101
AB2000 BG85 24 1151
NS9900 BG80 24 1123
ARC10 ZM62 27 1296
Ti-10 gen3 ZM62 26 1272
Precision ZM62 27 1243
Precision ZM62 27 1243
AT700 ZM62 27 1279
NS9900 BG80 24 1121
Ti-10 gen3 Zymax 67 26 1167
ARC9 BG80 24 1111
ARC7 Zymax 67 24 1127
Power Energy Speed 99931 ZM62 26 1237
ARC10 Zymax 65 27 1206
BLX Vertex ZM62 24 1168
Spira 21 ZM62 27 1243
Spira 21 ZM62 27 1223
ARC9 BG65Ti 24 1114
Spira 21 Zymax 67 26.5 1171
ARC10 BG80 25 1127
ARC9 BG80 24 1126
Ultra Pro ZM62 25.5 1182
ARC10 Zymax 62PT 26 1228
ARC10 ZM62 26 1228
ARC10 Zymax 62PT 25.3 1201
Ultra Pro ZM62 23 1182
ARC10 ZM62 24 1168
ARC10 ZM62 24 1168
AT900P BG80 29 1229
AT900T BG80 26 1169
ARC10 Zymax 67PT 27 1128
ARC10 ZM62 26.5 1241
ARC9 BG80 24 1117
ARC9 BG80 24 1127
ARC10 BG66UM 26 1244
AT700 ZM62 27 1254
ARC10 X-3137 26 1135
BS09 ZM62 27 1264
Woven 10i Zymax 67 25 1151
ARC9 BG80 25 1153
ARC10 BG80 24 1112
ARC9 BG80 25 1164
AT700 ZM62 27 1262
BS09 ZM62 26 1216
Woven 10i ZM62 24 1172
AT300 BG65 21 1000
BS10 ZM62 25 1185
SW35 ZM62 25 1196
BS10 VS850 25 1168
ARC9 BG65Ti 24 1088
AT700 ZM62 27 1251
ARC9FL BG66UM 25 1250
Ryogo Issen VS850 28 1224
SW35 BG66UM 26 1265
Woven 10i BG65 24 1089
Ti-10 gen1 BG80 23 1072
ARC10 BG66M 25 1238
ARC10 BG66UM 25 1233
ARC9FL BG66UM 25 1202
Ti-10 gen3 BG80 26 1134
ARC10 BG80 24 1087
ARC10 X-3136 25 1153
ArteryTec99 BG80 23 1084
NS7700 BG80 24 1110
Ultra Pro VS850 25 1156
ARC9 BG80 24 1153
MX80 VS850 25 1150
ARC9 BG80 25 1125
ARC7 Zymax 67 24 1159
NS9900 BG80 24.2 1141
ARC7 Zymax 67 24 1150
JSmash Alpha 1 BG80 22 1075
ARC10 Polyfibre Explosion B6 24 1138
ARC10 BG65 24 1054
NS9900 BG65 25 1124
MP29 BG80 21 1047
AT700 BG80 24 1060
NS7000 BG80 21 1030
Ryogo Issen X-3136 28 1200
Trinity Pro VS850 25 1200
AT250 LTD BG66UM 25 1236
NS9900 BG66UM 24 1186
ARC9FL BG66UM 25 1210
ARC9 VS850 26 1219
ARC9 VS850 26 1187
MX80 VS850 25 1148
ARC9 VS850 26 1187
ARC9 Polyfibre Explosion B6 29.2 1283
SW35 VS850 29.4 1220
SW35 VS850 29.4 1220
NS9000 BG85 27 1245
ARC10 PG BG80 27 1182
Ti10 BG80 27 1179
MP99 BG80 27 1181
ARC-Z BG80 26.5 1210
900P BG80 26 1160
900P BG80 24 1126
Jsmash 9004 NBG98 22 1151
Millenium 6170 BG85 26 1200
SW37 VS850 27 1168

[visor]

@kwun

WHOA!!

Those are measured after tension stabilized, not immediately after stringing, I presume?

[kwun]

@kwun

WHOA!!

Those are measured after tension stabilized, not immediately after stringing, I presume?

sorry. as these are clients' rackets, they are measure right after stringing.

[kwun]

it is hard to find a lot of tension stabilized data points. mainly because i don't always get to see the client again at the appropriate time after the racket is strung. if i use my own racket, then the sample size will be very small.

and also the tension loss is gradual and continuous until the string snaps, it is hard to pin point exactly the equivalent moment in the decay curve to measure the frequency. right after stringing is more reliable imho.

[visor]

[QUOTE =kwun;2048344]sorry. as these are clients' rackets, they are measure right after stringing. [/QUOTE]
Nooooooooo!
That's
too bad... as the frequency will drop another 50-100 Hz after stringing before stabilizing.

[visor]

it is hard to find a lot of tension stabilized data points. mainly because i don't always get to see the client again at the appropriate time after the racket is strung. if i use my own racket, then the sample size will be very small.

and also the tension loss is gradual and continuous until the string snaps, it is hard to pin point exactly the equivalent moment in the decay curve to measure the frequency. right after stringing is more reliable imho.

Sorry, kwun
but I've seen the frequency drop 50 Hz 1 hr after stringing, then another 50 Hz after 1 day, then another 50 Hz over the next few days before plateauing... all this without playing with it!


For consistency and repeatability purposes, I'd much rather measure at the plateau phase (even though there is still a slight gradual decay from playing and string creep) than the initial steep drop phase where a few hours make a huge difference.

[kwun]

Sorry, kwun
but I've seen the frequency drop 50 Hz 1 hr after stringing, then another 50 Hz after 1 day, then another 50 Hz over the next few days before plateauing... all this without playing with it!


For consistency and repeatability purposes, I'd much rather measure at the plateau phase (even though there is still a slight gradual decay from playing and string creep) than the initial steep drop phase where a few hours make a huge difference.

i assume you have seen these graphs from a previous thread:



this is the thread:

http://www.badmintoncentral.com/foru...-(maybe)/page2

yes. it does look like it plateaus, but if you look at the (first) plateau, it is not flat, even over time, it is still dropping.

assuming unused, it will eventually stop, but we do use the racket and each time used it will get a big bump down. the question then is where do we sample our data point?

[kwun]

i think ideally yes, we should let it sit for a week or so and measure where it eventually plateaus. but that's unpractical as we can only get many data points if we use clients' rackets and most clients won't wait around for so long.

[visor]

@kwun

Yes, thanks for pulling that graph up... that was the one I was thinking about.

So, as you see, I'd much rather have quality data points, than quantity.

I believe that since frequency is a reflection of tension, then some time must be given to allow it to stabilize before we can have any meaningful measurements. After all, tension (and our indirect measurement of it) will affect how the string performs in repulsion, power, touch, control, so we want to make it as reproducible as possible from person to person across the world.

[kwun]

i agree on quality over quantity.

but i have doubts on the exact condition required to achieve that quality.

as you can see from the graph i obtained through an actual racket, with 70 hours of stringing, the tension/frequency seems to have settled on around 1135Hz level. at this state, there are no external force acting on the racket. so it will eventually reach the equilibrium point of ~1135Hz.

however, at around 70 hours, i brought the racket to the gym, now with all the hitting, external forces (stretching) on the strings forced the string into another equilibrium point around 1110Hz.

i don't believe the racket will reach the 1110Hz equilibrium point if i hadn't brought the racket to play. it would've stayed at around 1135Hz for quite a few weeks. it may reach 1110Hz if left around for months. i suspect so because the internal tension force is not strong enough to shift the equilibrium quickly.


so what's my point? my point is that we must standardize on how long the racket may stay and whether we should allow it to be played.

if we really do want it to plateau, i believe we must leave it unplayed otherwise it will reach a different equilibrium/plateau that is not equivalent to the one when we leave the racket unplayed.

so my suggestion is if we do want it to plateau, leave it for N number of days. we can pick what N would be.

[ucantseeme]

SW35 with BG80 @29lbs: 1197 Hz, strung @Yonex German Open with EsPro, measurement at 6-8 hours after stringjob.

[visor]

SW35 BG80 @29lbs: 1197 Hz, strung @Yonex German Open with EsPro, measurement at 6-8 hours after stringjob.

Tks @ucantseeme .

Can you please update after a few days to a week.

[visor]

@kwun

Looking at your graph, anytime after 24h is reasonably stable enough to start measuring.

Of course I understand once the racket starts to be used, there will be some gradual 10-15 Hz drop after each session but this will also eventually stabilize after several sessions. Well at least Zymax strings behave that way due to their excellent tension retention properties.

[SSSSNT]

I measured using Carltune

My Victor BS12 with VS-850 is at 1040 Hz @ 6 Octave. It was strung digitally 6 month ago @ 23 lbs by an experienced stringer.

My Yonex Nanospeed 200 with BG-66 is at 1000 Hz @ 5 Octave. It was strung digitally 1.5 years ago @ 23 lbs by the same stringer.

Octave should be mentioned. That Nanospeed is a full octave lower.

[visor]

Thanx SSSSNT.

Your 6 months old vs850 correlates to my 1015 Hz vt80 with the same string at 24 lbs after 1yr. And after whacking some plastic birds it dropped further to 980 Hz. Plastic birds are really murder on strings!

[SSSSNT]

Thanx SSSSNT.

Your 6 months old vs850 correlates to my 1015 Hz vt80 with the same string at 24 lbs after 1yr. And after whacking some plastic birds it dropped further to 980 Hz. Plastic birds are really murder on strings!

Was yours also at 6 octave?

[visor]

Was yours also at 6 octave?

Don't worry about the octave thing... its just a designation for piano tuning. Just look at the frequency.