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Importance of properly mounting a racquet to "neutral" when stringing

Discussion in 'Badminton Stringing Techniques & Tools' started by taneepak, Jul 21, 2007.

  1. taneepak

    taneepak Regular Member

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    One of the principles in racquet frame design and choice of materials also applies to stringing a racquet, especially at high tensions.
    A racquet frame has a native "spring" or "rebound" properties, along the longer sides. You can try pressing an empty frame inwards from the sides to see this. Different materials and the homogeneity of the materials used in the frame have different rebound properties. Using different materials in the frame will produce a less than homogeneous rebound (use of elastin in a section of the frame). This native rebound property of your empty racquet frame has a sort of liveliness, which is a sort of added spring/power for the strings in your racquet. Unfortunately this liveliness is often "killed" off by poor stringing practices, including using a tie-off at the top cross string, but the most common cause is over-stretching of the frame at the N/S poles. Once a frame is overstretched, the native spring is gone-the frame is dead and has completely lost its liveliness. The racquet becomes a bit longer with a slight increase in swingweight but at a terrible cost.
    The best way to mount a racquet for stringing is first draw a tracing of the contour of your empty racquet top (about 4" will do) on a piece of paper stuck to a wall. You then mount the racquet in a neutral way, with no force or too much friction when clamping the frame. Contrary to popular belief the use of load spreaders is not a good idea. Mount the two N/S poles in such a way that the racquet can still be pulled out from the machine with a little friction.
    After stringing take your strung racquet and go to the same wall and draw a another trace over the first one. If the two traces look as one then your strung racquet will enjoy that extra spring that bad stringers have have sometimes robbed you without knowing why.
     
  2. jerby

    jerby Regular Member

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    so you are postulating that the truning of the supports, which can't be more than 1 kg of internal force, kill your rackets "natural spring"?
    With 22 mains and 24 crosses, that's over 1000 pounds of internal force, but my slight turning of supports kills off all feel?

    why not use a two-point machine?
     
  3. taneepak

    taneepak Regular Member

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    No, that is not what I mean. An unstrung racquet has a certain inward flex, more on the long side and less on the shorter side (head-throat). Improperly mounting the frame that results in a deviation from its neutral unstrung state will adversely affect this native spring or liveliness. For example, an overstretched strung racquet that is stretched to its flex limit will have no more spring in its frame to help your strings.
    With highly strung tensions a powerful shot will have a significant impact on the stringbed, which is supported by the frame, and with the frame's native spring or flex, this whole highly tensioned stringbed/frame interface, provided the frame's spring or flex has not been killed off by frame overstretching, will give you that extra "effortless" power.
     
  4. jerby

    jerby Regular Member

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    flex limit? that's way of the deep end in "bad mounting", who would do that?

    Where do you get the term "native flex" and why would minor distortion "kill it"?
     
  5. taneepak

    taneepak Regular Member

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    For a start, the next time you get a string job done try to use the tracing method qc check I mentioned earlier, for before and after. Use different colour pens or thin markers and see if the two colours merge or deviate.
    Racquet frame has a native flex property from its dimensions and the materials used. Materials that have have excellent creep, flex/fold, and low coefficient of thermal expansion characteristics will have better native flex than those with lower performance. Each time you hit a power shot at high tension the stringbed/frame interface will flex and spring back. If frame materials are poor in creep and other properties the stringbed/frame interface flex/rebound will be inconsistent and will lack a certain airiness or liveliness. As a matter of fact Yonex claims that its elastin patch on a section of the frame does similar thing, which I doubt because of the non homogeneity of the frame material.
     
  6. jerby

    jerby Regular Member

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    sure, I'll do that...next time I restring...which woudl take a while now it's off-season (just 3 more weeks, just 3 more weeks, almost there, just 3 more weeks ;)) and I play once a week...

    so a homogeous racket (as far as you can speak of homogenous with heat/molded graphite...) will lose it's "native flex" when it is slightly distorted? is it less homogenous when you bend it? if so don't you see the paradox? it bends(distorts) bécause it's homogenous...
     
  7. taneepak

    taneepak Regular Member

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    By the way, my comments apply only to racquets strung at high tensions. Low tensions are simply too low to overcome its huge trampoline effect which predominates and masks everything.
     
  8. taneepak

    taneepak Regular Member

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    When the whole racquet frame is made from one type of material it is homogeneous. If two sections of a frame, lets call them elastin, are made from a different material and placed at around the 4-5 o'clock locations on either side, and the rest of the frame is made from say HMG, then the frame is not homogeneous. Even between two homogeneous materials, say HMG and Vectran, the latter will have superior native flex/rebound characteristics. When a racquet is strung, the ideal is to have the same exact shape of the before stringing shape.
     
  9. jerby

    jerby Regular Member

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    yes, yes, we all know how much you oppose "low tensions"... I strung my arcket up to 27lbs at points, and let it drop slowly (with pg65, it's natural :p)
    I failed to see any magical barrier between "high tension" and "low tension"...
     
  10. jerby

    jerby Regular Member

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    so, you've said that about 3 times now....
    why? why would a 2mm shorter racket perform like crap?
     
  11. silentheart

    silentheart Regular Member

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    Most of stringer here try to string racquets to the same shape as unstung one. Unless the customer request so. I just want to bring up a couple points.
    1) At high tension, stringer's experience and skill are very important and just like Taneepak said, any mistake will hurt performance. However, there is a big issue of using tracing method because there is an error already by hand tracing your racquet on a piece of paper. Some time the trace can be up to 2~3 mm. If that happen, and your ending product match to your trace, isn't your racquet is stretched?
    2) A racquet frame is homogeneous is just a assumption. What if yu have a racquet like Ti10 where it has ti mash at some part of the frame and no ti mash in other. do you need to compensate for that for every different racquet?
    3) How high of tension is high? Most of player use racquet string at tension less than 25X27, I consider anything higher than that as high tension. With all respect, 27X30 might not be high for you. The points you brought up are valid, but for most of players use high tension, they either string them self or has good stringer working for them already. They know what they want.
    4) How do you apply tension to cross? 10% or 2lb? Because a same racquet string at 27X29 vs 27X29.7 vs 27X30 will have different shape under mag glass. I am sure 1st vs 3rd will be different by 1~2 mm for sure.

    I just want to say your points are good under theory. However, under normal practice, it has no effect to majority of us.
     
  12. taneepak

    taneepak Regular Member

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    The tracing method I suggest is to be done against a wall, not on a piece of paper you put on a desk. Just stand your racquet at the same spot against the wall and stick a piece of paper on the wall around the frame top area and use a line to align the centre of the racquet. You don't have to trace the whole frame, just from the top grommet #6 on the left to grommet #6 on the right. You will be surprised at the precision of this method.
     
  13. taneepak

    taneepak Regular Member

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    You can try this out, using an A/B comparison, using same racquet, same string, tension 28.5lbs/31.3lbs for both, with one racquet in neutral shape when strung, and with same racquet shorten the frame by 2mm (more squarish).
     
  14. fishmilk

    fishmilk Regular Member

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    Nanospeed 5000, Muscle Power 21, Muscle Power 18, Isometric 75-MF Light, Isometric 65 Light, Carbonex 21, Carbonex 20, Carbonex 8000 Light.

    In the 2007 Yonex Catalog, these are the racquets I found to have a frame ADVERTISED TO BE (remember these are all just claims, for all we know) entirely composed of the same material. Most of these are beginner's racquets. So unless you're a classic CAB user, this does not apply. It may be good information but a decade or two too late.

    Besides, theories are one thing, but to me, there is so much more in play when it comes to real practise. Such as the lower end of the LF Mounting. I know Pete and Howie had much more success with their higher end mounting, but under theory, there is absolutely no reason why the outcome of my frames should be so vastly different. I see no flaw in the theory or it's application, but why is it that without rushing and using fairly consistent techniques IMHO, I can get two totally different outcomes in terms of the frame's distortion? Theory is great, but in real world application, there is much more that comes into play.
     
  15. jerby

    jerby Regular Member

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    shouldn't it be 28,5x 31,35 ?
    this way, it's only 0,98% and cause distortion and ruin the rackets vative flex!
     
  16. taneepak

    taneepak Regular Member

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    Actually I am putting this native flex of the racquet frame theory into practice. I am about to put together a new racquet with above average native flex properties, but without using very expensive materials. I may bring one to the World Championships in KL in August for testing. Any volunteers?
     
  17. jerby

    jerby Regular Member

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    e-1000 all over again?
     
  18. taneepak

    taneepak Regular Member

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    The TEP Select version of the Vectran E-1000 is nothing to be sneered at. Have you tried one? I doubt it because they come in a limited edition of only 40 racquets. I am sure you are not one of the lucky ones.
    The new racquet I am working on uses the very common HMG material to cut down costs but with a different cross section to improve its native frame flex. It is surprisingly lively for such a low cost materials racquet. I suspect this is again not your cup of tea.
     
  19. jerby

    jerby Regular Member

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    well, yes that is correct...I wasn't pointing at the rackets performance, who would I be to judge (like you said), but more towards the "situation" on BC with the E1000....

    and yes, you're right, chances are pretty close to a 100% that I'll never try it, but that has nothing to do with your, or your rackets (heck, I haven't tried a lot of rackets...)
     
  20. silentheart

    silentheart Regular Member

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    I am not a 3 yr old any more. My mom spank me after I draw my last master piece in the wall. Sorry about the joke.

    As you mentioned to trace the racquet on the wall (table or any flat serface) you are introducing errors during the drawing process. Also, what is an acceptable range of error? Is 1 mm OK for 27X30 lb? Is 2 mm of for 30X33 lb? Is it OK to have the racquet short or long?

    I think most of us string racquets trys to practice and string the racquet to the unstrung shape unless user asked otherwise. To achieve the result and correct measurement, you need some expensive machines or lab equipments to do so. These are something we do not have at home and only some lucky guy like you have at work.

    Don't get me wrong, I like your theory, I just having problem practicing it at your level without winning a Lotto or rob a bank for it.
     

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