Drawback Again

Discussion in 'Stringing Techniques / Stringing Machines' started by Imago, Sep 30, 2013.

  1. Imago

    Imago Semi-Pro

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    Today, I got the Tourna Stringometer and the first thing that apalled me was the absurd difference between tensioned cross string and just clamped string after releasing the string from the drop weight clamp - it was 8 kg when on the machine (Pro's Pro Pioneer I) and between 8 and 14 kg, when removed from the bed.

    This is ridiculous...
     
    #1
  2. Imago

    Imago Semi-Pro

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    No editing available for us n00bs, so it's Stringmeter to begin with, mains are PP Black Out 1.24, crosses - Babolat xcel 1.3 mm.
     
    #2
  3. Irvin

    Irvin G.O.A.T.

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    What are you talking about?
     
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  4. Imago

    Imago Semi-Pro

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    From 8 to 14 kg less than the set/desired 28 kg - when measured off the machine.
     
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  5. diredesire

    diredesire Super Moderator

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    As compared to what? The reference tensioner? Or were you measuring 28 kg while on the stringer?

    The tourna stringmeter is NOT designed to measure reference tension. You use it to make relative measurements to track tension loss.

    It CAN be close, but isn't accurate for measuring actual tension. I'd also like to point out that reference tension is only a reference for a stringer/player/customer to determine how to change their reference tension 'number' for a desired stringbed stiffness.
     
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  6. Imago

    Imago Semi-Pro

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    The criterion is one and the same - Stringmeter. I have three measurements:

    1. When the string is pulled by the ratchet gripper and the clamps are set.

    2. When the string is released from it and clamps draw back by 2 or 3 mm, depending on the angle of the holding arm of the clamp.

    3. When the racket is off the mounting system - seems that there is certain change in the geometry of the frame, which is less pronounced when I use poly for crosses.
     
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  7. Irvin

    Irvin G.O.A.T.

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    I am not sure what a Pioneer 1 actually is but I assume you have two flying clamps / drop weight. Do you use one or two clamps to string your crosses? and when you remove the clamp do you re-level the weight arm?
     
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  8. Imago

    Imago Semi-Pro

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    Here is a picture

    [​IMG]
     
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  9. Imago

    Imago Semi-Pro

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    Actually I put the holding ratchet finger down so the drop weight lever is always levelled and horizontal when tensioned.
     
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  10. Irvin

    Irvin G.O.A.T.

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    I have no idea what a holding ratchet finger is. If it is something that holds the weight bar level it can never drop when tension drops.
     
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  11. Imago

    Imago Semi-Pro

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    It is the finger that holds the sprocket. You cannot remove the string from the gripper when the finger is up.
     
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  12. Irvin

    Irvin G.O.A.T.

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    Sorry I am lost.
     
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  13. Imago

    Imago Semi-Pro

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    Then I am in real trouble! :)
     
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  14. Imago

    Imago Semi-Pro

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    I could minimize the drawback by putting the second clamp as close as possible to the main holding clamp.

    I wish also the manufacturer made longer the rotating base of the clamp so that we could use the right clamp for holding the cross on the left side. Then there will be no drawback at all.
     
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  15. struggle

    struggle Hall of Fame

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    not even sure why you are measuring so many times.

    measure once you are done (in a few places of course). if you like the way it plays, shoot for the same number again, if not adjust.

    you play the entire stringbed, not just one string.
     
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  16. Imago

    Imago Semi-Pro

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    The other question is, if the differential tension is 8 kg and I set 35 kg on the lever, would I get 27 kg as a result, and - more importantly - will the frame hold?
     
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  17. struggle

    struggle Hall of Fame

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    it's a dropweight, therefore likely dead on accurate. (if in doubt, try a calibrator, springscale or luggage type scale).

    if you are used to a number, stick with it. don't use a stringmeter as
    anything but a reference, as has been stated....it doen't give you accurate tension numbers. I have one.
     
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  18. Imago

    Imago Semi-Pro

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    Within its own sphere of action, it's pretty accurate and veridical - I have 8 kg weightdrop because of the drawback, like it or not.
     
    #18
  19. illzoni

    illzoni Rookie

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    That looks identical to my Alpha Pioneer DC+. Which I love.

    The 'finger' is the ratchet on the drop weight pivot point. It allows you to lift the drop weight arm without the linear gripper rotating counterclockwise. I have no idea why he would think not using it would give better results....
     
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  20. struggle

    struggle Hall of Fame

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    sounds like you need to work on technique, perhaps. not trying to judge, just saying.

    I don't see that much drawback (8kg = almost 20 pounds) and i don't use a CP machine.

    most drawback comes out after the "next" pull.

    again, the stringmeter is not a good tool for what you are trying to do, IMO. If you have that much drawback, something else is going on, but just a guess.
     
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  21. struggle

    struggle Hall of Fame

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    also, there is more then one way to use a stringmeter depending on single string or full bed.

    I assume you already know that, but that shouldn't affect the readings you are using, as they are relative to one another.
     
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  22. Imago

    Imago Semi-Pro

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    Because when it is up and the tension is pulled, there is no way to remove the string from the gripper - you have to cut it or loose the other end. Thanks, but no.
     
    #22
  23. struggle

    struggle Hall of Fame

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    let us know when you figure it out. id be worried too if i lost 20 pounds during a string-job on a solid machine.
     
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  24. diredesire

    diredesire Super Moderator

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    OK, let me get this straight: you ARE measuring with the stringmeter in all the above situations?

    What are the differentials between all the above situations? You are seeing an 8kg differential between situations two and 3? 1 and 2? 1 and 3? Besides the fact that the tool you are using is not designed for this measurement, that's sitll outrageously high. Please use a permanent marker to mark the string after clamping (but before removing tension). I'm curious if your string is slipping in the clamp (not just drawback).

    This would actually be a rather crappy design unless it was a glidebar. It'd require a lot of space to manipulate the clamps, and you're limited by the mounting stocks...

    I still think you are thinking about this the wrong way, since actual tension is largely, largely irrelevant. The short answer is YES, but with the caveat that you have an accurate way of measuring the tension on and off the machine. Torquing the string at an intersection is only so useful, and there are assumptions and dependencies that you need to account for (strings bordering both sides of the string you're measuring, for instance, or all four sides of an intersection).

    The frame should be fine as long as there's no prior damage.

    It's more or less unrealistic to see that high of a tension drop simply and solely attributed to drawback. There's something else amiss here, either the assumptions you're using (read as: don't trust a stringmeter), or other equipment failure (clamp slippage, mounting stock issue [which still wouldn't account for that much tension change], operator error, etc). More info needs to be added before we can (accurately) diagnose the issue.
     
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  25. Irvin

    Irvin G.O.A.T.

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    I can only assume you think drawback is the issue here but I have a feeling that is not all there is to it. Try this little experiment the next time you string. While you are tensioning cross string x the last clamp you clamped was on x-1, and the one you are about to move is on x-2. When you tension string x make sure the bar is level and befor moving the clamp from string x-2 release the base only of string x-1. What happens to the bar? Leave that base clamp released and move the clamp up to string x and if the bar is not level level it. When you clamp string x clamp the string first and then put a slight pressure on the base of the clamp before locking it toward the tensioner. Continue doing all the crosses that way and see what happens to your readings.
     
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  26. Tamiya

    Tamiya Semi-Pro

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    +1 to pretension on clamp base

    And when you do final tie off, cinch up the knot as hard as you can by hand
    then hold the loose string end tight whilst you undo the clamp.

    I use a spare clamp on the string to give a t-bar handle to pull with.
     
    #26
  27. Imago

    Imago Semi-Pro

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    Yes

    Between 1 and 2 - 8 kg
    Between 1 and 3 - from 8 to 14 kg


    No, the difference between 2 and 3 is from 0 to 6 kg

    [/QUOTE]Please use a permanent marker to mark the string after clamping (but before removing tension).[/QUOTE]

    Good idea, thanks!
     
    #27
  28. Imago

    Imago Semi-Pro

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  29. Imago

    Imago Semi-Pro

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    The bar falls down by 9 degrees.
     
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  30. Irvin

    Irvin G.O.A.T.

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    No I never have but I would not want to either. If I know it (the drawback) will be there why quantify it? What you're looking to quantify is the final product not drawback.

    That is a lot of tension loss not due to drawback but due to the string relaxing.

    Many people don't like a lockout stringer because it strings too low (that is outside the scope of this thread,) but you have to face it the drawback (string relax) will be there and you have the same thing. And so do I on an electronic machine. As the string relaxes tension goes down especially on crosses. Instead of checking tension all the time just take the time to level that bar over and over and over. When you get done check the tension of the string bed.
     
    Last edited: Oct 1, 2013
    #30
  31. Imago

    Imago Semi-Pro

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    So far this seems to be the best solution

    [​IMG]

    I have only to find a metal extensioner between the two clamps so that the right clamp goes down to the frame. But even now the weight reduction is minimal.
     
    #31
  32. struggle

    struggle Hall of Fame

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    this picture alone tells me something is wrong. your clamps (just one should suffice) should be at the frame, not out in the middle of the stringbed area.

    spin that right side base clamp out so the clamp is at the frame, make sure the string clamps are not slipping...adjust as needed.

    perhaps your basesclamps need adjusting.
     
    Last edited: Oct 1, 2013
    #32
  33. Irvin

    Irvin G.O.A.T.

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    I agree with tbuggle this is not a solution it is a problem. I don't know what your problem is maybe it would help is you could shoot a video. Have you marked the string to see if the string is slipping through your clamps? Have you cleaned your clamps?

    I would really be interested in seeing how you do that for the mains.

    EDIT: Is this a joke to test us? To borrow a quote from John McEnroe, "You can not be serious."
     
    Last edited: Oct 1, 2013
    #33
  34. Irvin

    Irvin G.O.A.T.

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    I would like to see you weave your mains. I am really not believing what I am seeing. Maybe you tension is falling off because there are no mains and the racket compression is throwing you off. Hope that is your racket.
     
    #34
  35. Imago

    Imago Semi-Pro

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    The right clamp is in the middle because only there it can use the stronghold backup of the left clamp, because there is no drawback when the clamp base arm is at 90 d to the rail. If I put the rignt clamp to the frame, then I'd better do not use it at all - there will be residual drawback and I have to deal with it again.

    Mains are not topical now. I skipped them for brevity. Just imagine that they are already there. :)
     
    #35
  36. Muppet

    Muppet Hall of Fame

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    Drawback is normal. It will get taken up by the next tension pull. Just string your racquet normally and measure the stringbed stiffness afterward. I think all of this extra stuff you're doing is throwing you off.
     
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  37. Imago

    Imago Semi-Pro

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    Actually, I have solved two problems - there is no more drawback and there are no more relaxing strings. Final tension is almost identical all over mains and the crosses thus producing an isotropic stringbed.


    [​IMG]

    [​IMG]

    [​IMG]


    Thank you for your understanding and friendly support.
     
    #37
  38. babyhagrid

    babyhagrid Rookie

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    I spy a dodgy grommet on the mains at the throat. Fresh grommets are in order.
     
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  39. Imago

    Imago Semi-Pro

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    This racket has not been strung for more than 20 years. It's an experimental USSR (1991) licensed production of Kneissl.
     
    #39
  40. struggle

    struggle Hall of Fame

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    you are not stringing properly, not surprised you are having problems.

    i'm done with this thread, best wishes.
     
    #40
  41. Imago

    Imago Semi-Pro

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    I had problems because I was stringing properly. Now, with this joined clamps method for the crosses, I don't.

    For those who got interested, it is important to hold tight both clamps like this before fixing the base.

    [​IMG]
     
    #41
  42. Chotobaka

    Chotobaka Hall of Fame

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    Wow. Just wow.
     
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  43. Wikky

    Wikky Rookie

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    .... what the
     
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  44. mad dog1

    mad dog1 Hall of Fame

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    And just when you think you've seen it all on tw forum...
     
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  45. struggle

    struggle Hall of Fame

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    That's it, I'm ordering an extra set of swivel clamps!!

    edit: oh wait, nevermind.
     
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  46. mad dog1

    mad dog1 Hall of Fame

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    One extra set isn't enough. Think you need 2 for each side. Actually 3 for each side will insure no drawback at all. :twisted:
     
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  47. Imago

    Imago Semi-Pro

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    Fact is that with my method there is no more residual drawback - which is unfortunately seen even in the most sophisticated electronic machines. Instead of being ironical, just measure the final tension of your crosses. If I was a manufacturer I would consider dialectical comeback (Aufhebung, as Hegel would say) to a circling clamp base so that it could stay always parallel to the string clamped.

    Update: Actually, such system is already on the market :)

    http://www.youtube.com/watch?v=X4AOxZExPaM&feature=player_detailpage#t=70
     
    Last edited: Oct 13, 2013
    #47
  48. mad dog1

    mad dog1 Hall of Fame

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    you do realize you are comparing an entry level drop weight machine that costs ~$350 to a high end machine that costs ~$9,000, right? :shock:

    it might come as a shock to you, but the $8,650 price difference gets you a MUCH higher quality machine. one of the features of higher end machines is less drawback. so if you want less drawback, get rid of your cheap dropweight and buy a high end machine because the way you are stringing it is just wrong by leaving 3" of string untensioned. sure you might not have any drawback, but you will not recover the tension on the 3" of untensioned string on the next pull so the tension of the string bed will be lower than targeted unless you have compensated for this by increasing your reference tension. the amount of tension loss you experience from the 3" of untensioned string will be greater than the amount of tension loss you experience from drawback assuming your base clamps are adjusted correctly.

    but obviously you know what you're doing with your "innovative" new stringing method and it's working for you, so keep on doing it.
     
    #48
  49. Shroud

    Shroud Hall of Fame

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    New to stringing and really trying to understand this thread.

    I have come to some conclusions and please check if I am reading right:

    1. The Op has tension loss vs. reference tension.
    2. This though is problematic because the measuring device measurements have nothing to do with reference tension...there will always be a loss vs. reference tension, and the OP is chasing his tail.
    3. Turns out he is clamping with 2 clamps at the middle of the racket, and while that solves drawback, it creates lower tension because of the 2-3+ inches of untensioned string.
    4. It might be possible to adjust for this technique by being consistent and adjusting tension and the op is claiming it works now. In a GENERAL sense as one adjusts for cp and lockout machine differences.
    5. Though for consistency clamping near the frame and coping with draw back like in Irvins video is probably a better way.
    6.Mains would have an even worse time because of the distances involved.
    7. I filed Hegel in the "you have to know the stuff you don't need to know" category though maybe I should reconsider.

    Also how would one start mains and clamp like the op is doing. Wouldnt a starting clamp be a must?

    Also how can the OP compensate when tying off mains and crosses?
     
    #49
  50. Irvin

    Irvin G.O.A.T.

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    Let me stop you there if you don't mind. You're never going to get reference tension on the tensioned string because of surface friction at the frame. When you tension two crosses and clamp them off and you are ready to tension the next string here is what has happened. The string you just tension pulled the clamp back into the racket lowering the tension on thestring you just tensioned. When the tension on that string lowered it allowed the other clamp to drawback too. This whole thread is about drawback and how he managed to eliminate it.
     
    #50

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