Tension loss experiment

how did you measure the string? cut and measure?

 

a few questions... in the interest of science

did the string maintain the stretch after the tension was released.

have you tried stretching it for really really long periods to see if the rate of stretch slows?

what i'm thinking is that the same way you have to wait for your strings to 'bed in' the string would stretch initially for the first few days, but then stop. the tension loss that you normall experience with your racquet would be more difficult to simulate. since it's dependant on how often you play, and a little on your playing style. obviously the harder hits increased the tension on the strings a great deal (anybody care to estimate the increase in tension?) as i'm sure yuo know, repeated stretching reduces the plasticity/elasticity (can't remember which one or if it's both) which results in the loss of tension.

hope this makes sense..

Neil

 

9 hrs should be enough.

Seriously, when i string rackets, I usually let the center pieces staying (also drop weight machine) for 15-20 sec at least, and re-adjust the leveler is necessary. The side pieces takes a lil short time, say around 3-5 sec.

 

Hi Bensap,

Please forgive me if I misunderstood any part of your question.
To figure out the tension loss of 1mm over 1m string, you need to know the spring constant of the string. Without extensive testing, my very rough guess from your number is about 25lb*0.001 per 8hr period. Given we usually use 5m to string on main, you should see about 0.375lb drop per day. THIS IS A ROUGH EST!
However, this is only apply to if you string the racquet and left do not use it at all. If you play with it, the string is subject to different forces. The tension will drop faster in playing condition.

Please correct my post if I made any mistake...

 

benasp, ur test is not bad first level experiment.
it is not possible to correlate delta length to tension loss without knowing the string properties from the manufacturere but lazybuddy estimate is pretty close. The 1mm stretch is static tension loss as what LB had said. If u play some games, tension go down even faster. Constant tension is mild if u compare to tension spikes duing a smash, which can double to 46 lbs.(rough guess)

 

i have 2 rackets strung on the same type of machine( pacific) but different stringer.

both strung at 25lbs. one was strung more than 3 months ago (racket X) and the other strung able 2 weeks ago.( racket Y)

was playing yesterday and while waiting for my turn, took out both rackets to feel the tension difference. X was still holding tension very well though i use it as a spare for the last 3 months but it shouldnt be anything less than Y which i only have played for 2 weeks. Y tension is already significantly lesser than X!!

stringer X did tell me before that his strings can hold tension better becos of the way he strings and also he wil wait for the machine to finish the last pull ( if you look at the stringing, you will notice the machine pulls, stops and suddenly pulls again for a little more). he claims that the last pul will help keep the tension well. now what he says is evident.

 

it's not a surprise.
racket and string performance do determined by stringer method.

 

I assume stringer X uses constant pull machine. If both stringer uses same model machine, I will say stringer Y is not a good stringer or does not know his/her machine as well. If 2 machines are different, stringer X has a better machine IMO. Either way, go to stringer X if cost is not too much different.

 

I think you've slightly misunderstood something. once your racquet is strung there is tension applied. The tension due to striking the shuttle is on top of that. Once the racquet it strung it is under tension until you break a string.

This demonstrates the quite amazing properties of the string we use, since a racquet can maintain it's tension for quite extensive periods of time if unused, obviously the higher the tension the shorter this time is. but i would guess that anything under 25lbs would last a fair time.

obvisouly there are a great deal of environmental factors which affect string performance.

keep experimenting... if you can find a way to make the tension spike like it would during a game then go for it - i think the results would be extremely interesting..

Neil

 

Can you please explain a little more about this last pull on a constant pull machine? I am using a constant pull dropweight. So am I supposed to leave it until it suddenly pulls again and then go on to the next string? I know many stringers like to keep their practises AND customers to themselves. However if you could expand on this, this would greatly help me and maybe lots of fellow stringers. Thanks in advance.

 

For cross strings wait for 30 to 60 seconds . The cross strings face more frcition from the main strings and do not stretch to its limit under very short period of time, 10 seconds . Or you can do the tap dance with your fingertip on the drop weight but do it very lightly .

 

??? Constant pull machine is just like the words say. The string is being pulled constantly at the same tension untill the string has bee released. There are some hand crank or electric machines use break once the tension is reached. Oftentime (especially at high tension without pre-streching the string) the string will strech a little and tension is lower after the break has been applied. Some of the stringing machine which use break mech. will give it a "last pull" to add slight additional tension one the string to compansate the tension loss. For dropweight machine and electric constant pull machine does not have this problem and thus the "constant pull" machine will produce more accurate tension accross the stringbad when it is use correctly. That is why LB suggest to let weight sit for 10-15 sec. Also, for your info, electric and hand crank machine need to be calibrated once a while. Drop weight machine is always accurate unless the gravtational constant is no longer 9.8m/(s^2)...

 

60 sec is way too much I think. I agree to let it sit for 10-15 sec, as compare to a quick set of 1-2 sec, 10-15 gives u way better (accurate) result. However, the difference btw 15 sec and 60 sec will be very minimum in quality.

 

I was just wondering, because I know most of you guys can string in an hour or less. Maybe I'm still not experienced enough. I've tried just about everything I've found on the internet about saving time.

Right now, I weave one cross ahead, and I keep the end of the stirng almost at all times. My machine is dropweight but bc of the one pull any angle tensioner, it should be much faster than regulary dropweights. Still I have not been able to break the 1 hour mark... I know the speed of weaving makes a huge difference but I don't think I'm weaving THAT slow... I'm a bit reluctant to wait longer because my time is so slow already. Just wondering what your times are when waiting 10 - 15 secs per pull. And if you have any time saving techniques I'd greatly appreciate it.

 

For me, the fastest string job took 1 hour 15 minutes. It took me 15 minutes to complete the mains but the crosses required an hour due to those shared grommets (this was before I took the advice of the BFer of using tooth floss).

I would recommend you to pre-weave the crosses once you finish the mains.

 

I too am still working on trimming my time. I find that it's not just one thing that determines how long it takes you to turnaround a racquet. Your weaving adeptness, your familiarity with the pattern, dealing with shared/blocked holes, dealing with string twists, etc. all play important roles. For instance, I can do my standard 22x22 ATW pattern in about 45--50 minutes now. Still too long, but better than 70 minutes a few months ago. But, I've started to also do a 2-piece bottom-up pattern after watching the stringers at the recent WC. That still takes me over an hour to complete---even longer if I use the Hi-Qua B-696 string because it's hard to get through a blocked hole and, once you get it through, it tends to twist when pulled---because I'm still not familiar with the pitfalls of that pattern.

So, based on my very limited experience, all I can say is string as often as you can, the more the better; and, establish a routine and do everything the same way everytime.

FWIW, HTH.