How important is the levelness between racquet and tension head

Discussion in 'Stringing Techniques / Stringing Machines' started by cj6666, Jul 29, 2010.

  1. cj6666

    cj6666 New User

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    Installing my Wise tension head now. And unfortunately since I am not installing it over a crank system, I had to use the drop weight adapter and some drilling is involved, but I did it.

    The question is: My old system is a round turning gripper and my racquet can swing across the tension head. With the Wise head, because it is travelling in the horizontal direction, the linear gripper in the Wise head will collide with the butt cap of the racquet handle. I will use a couple of washer to move my racquet station up but that will increase the angle of the racquet and the tensioner. I did a rough measurement, the holes on my racquet is about an inch higher than where the diablo should grab the string.

    If you install the Wise head on your originally crank system, is the racquet and the tension head level with each other? Stringing the center main strings how does one avoid hitting the handle/butt cap?

    Thanks for your advice. CJ
     
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  2. rich s

    rich s Hall of Fame

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    Take the washers out and lose the ability to rotate the turntable 360*. The straighter the pull from the frame to the gripper the less tension loss will occur.

    By raising the table and allowing it to rotate 360* the pull down angle imparts friction on the string where it comes thru the frame/grommet thus reducing the effective tension applied to the string which reduces string bed stiffness.

    This is what you want to see...... http://www.photostringer.com/images/Gamma_602FC_061205-04.jpg ..... as straight a pull as possible.
     
    Last edited: Jul 29, 2010
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  3. cj6666

    cj6666 New User

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    Thanks Rich.

    I'm fine losing 360 capability. And perhaps for the few couple of center main holes just let the Wise head and the handle play a bit of tug of war?? ... they will be rubbing against each other...
     
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  4. GPB

    GPB Professional

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    Exactly... how would this work, when you're pulling the mains and the handle wants to be where the tensioner is? Just let them fight it out (hopefully with the tensioner winning...) or what?
     
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  5. cj6666

    cj6666 New User

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    I strung two racquets this afternoon. One with multi string and the other poly-synthetic hybrid. And only on one main hole for both racquets the handle is touching the linear gripper while it pulls. Since the gripper still seems to move freely and the reading does not seems to affected dramatically, I am simply going to assume there is no adverse effect. Cheers.
     
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  6. rich s

    rich s Hall of Fame

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    I hold the handle about 1/10th inch off the gripper until it stops pulling then let the handle rest against the gripper. Has not been an issue doing it this way.
     
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  7. Technatic

    Technatic Semi-Pro

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    360 Degrees Or Pulling Accurately???

    I would like to bring up a different subject that might be useful here:

    But I assume that you buy the Wise head to pull as accurate and Constant Pull as possible.

    In that case the next consideration may be useful:
    There is an important argument for stringing machine designers to put the tension head at the level of the string bed, so that the tensioner pulls the strings straight through the holes:

    There is no friction between the string and the grommet so you do not loose tension!!


    If a string is pulled downwards the vertical component (V) of the force pushes the string into the bottom of the grommet-hole and this causes loss of tension (W).

    [​IMG]

    This loss of tension is especially bad when the unit makes its “constant pull stroke” to compensate for slow elongation of the string. In that case the tensioner can not sense the loss of tension accurately and will wait longer before it will repull.


    So you have to make a choice between:
    - Having the best maximum constant pull accuracy and not having the 360 degree rotation.
    - Having the easy pull of the central main strings and loosing tension on all the other strings.

    Of course it is not for nothing that higher quality machines have solutions for this:
    - The big Babolats have the self lifting tension head so that they always pull at the level of the stringbed.
    - The Stringway machines pull at the level of the string bed and have the Concorde System to pull the centre mains without friction.

    Just my 2 cents.
    Tecna
     
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  8. rich s

    rich s Hall of Fame

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    The second is not an option IMO.... so no choice need be made.
     
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  9. Technatic

    Technatic Semi-Pro

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    Why????

    I fully agree, but the big questions is:
    Why do so many machine designers choose the second option then??
     
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  10. rich s

    rich s Hall of Fame

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    Would you want to market the only machine that doesn't offer 360* rotation?
     
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  11. jim e

    jim e Hall of Fame

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    Some of the newer machines now have a raising tension head, so you have the 360, and when tension, the head will raise to the same level.

    But taking into consideration all the other areas that can effect tension, just how much is lost with a little elevated table to have 360. Take into consideration the angle pulls on different areas of the racquet with any machine, where the tension head is not dead straight and this can occur on a machine thats at the same elevation, but friction with the sides of the grommet, as all pulls are not perfectly straight, and also tensioning the cross strings where there is friction with the main strings allowing inaccurate tensions, also, stringing some O port racquets where you use the boomerang that adds extra friction to effect final tension, or using a brake that makes some good angle pulls that effects final tension, do you really think that a turntable thats slightly elevated to allow 360 turns makes that much difference in the final outcome?We are not talking about a very much discrepancy where the table is elevated a great distance like the above poster shows that picture. Also, why do many pros have their racquets strung with a star 4 or 5 that has 360 and no elevating tension head, does it really matter in the grand scheme of things?Its evident that stringing racquets is not an exact science.You just try and duplicate each time doing the best you can, irregardless of 360 or not.
     
    Last edited: Jul 30, 2010
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  12. Ash_Smith

    Ash_Smith Hall of Fame

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    ^^^ Think your final sentance hits the nail on the head Jim - if your client likes your results then you need to repeat that for them regardless of the method or system or machine. If that means using a slightly higher tension to compensate for friction from lack or 360 rotation then so be it. Overall DT is (I am coming to believe) most important so if you can repeat that for your players that is the most important thing.

    Ash
     
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  13. Clintspin

    Clintspin Semi-Pro

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    Technatic what is the Stringway Concorde System?
     
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  14. rich s

    rich s Hall of Fame

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    When you are designing a machine from a clean sheet, you (the designer) can compensate the applied/reference tension to account for the losses Jim E describes related to average pull thru angle.

    Losses due to friction of pulling crosses over/thru mains are a fact of life regardless of the machine or frame and O port losses are a result of racquet design not machine design/performance.

    When I converted my Gamma 602FC from a dropweight to employing a Wise 2086 I originally mounted the gripper/tensioner at the same height as the drop weight drum to maintain 360 rot and pull angles, however at the same reference tensions, the two different mechanisms produced two extremely different string bed stiffnesses. The Wise stringbed was considerably less stiff and unplayable in my opinion. Whe I revised the mount to make the pull thru angle (virtually) zero, the stiffness of the unmodified drop weight was indistinguishable from revised Wise mount with zero pull thru angle.

    I would think that since the Wise is a stand alone device that can be installed on any crank and most drop weights, that it's design does not compensate tension for pulldown angle as the design would be for a single "point" thus the machine pulls the reference tension in a straight line only.

    The OP had just revised his machine to accept a Wise, similar to what I did years ago....... in this instance I would believe that a geometry that establishes a straight pull would suit him best this way he is not having to factor his tension up to create equivalent stringbed stiffness performance.

    In the end I was one of my own customers and decided I didn't like the feel of the stringbed..... as a the stringer I decided to revise the geometry so I wouldn't have to factor my reference tension for mine and my customers frames and experiment with each new frame presented to me to string.....

    I believe the OP is best suited with a straight pull as machines designed with some sort of pull down must be compensating for the pulldown angle otherwise the stringbed stiffness would be considerably softer....

    my $.03
     
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  15. Technatic

    Technatic Semi-Pro

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    Lof of angle talk

    I think that the only brand (Stringway) that does that sells quite well in the market, so why not?

    I agree fully that there are a lot of losses in the system of stringing a racquet. But I would like to divide them in avoidable losses and “build in” losses.
    As soon as you try to string on stiffness, so aiming at a certain SBS after finishing, every detail has influence on the result.
    I think that a measuring tool is a better reference than a player (apart from the pros).

    So to obtain the best possible result I think that you have to avoid every unnecessary loss.

    I do think that the experience of rich s confirms that pulling straight is certainly preferable.

    And apart from that we are advising the OP so why not tell him every detail so that he can judge by himself what to use?

    Technatic what is the Stringway Concorde System?

    Stringway offers a system that “angles” the turntable so that you can pull the centre main strings without friction while you pull all the other strings at maximum accuracy.

    [​IMG]
     
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  16. cj6666

    cj6666 New User

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    Hi guys,

    Thanks for wonderful input and discussions.

    Ideally, we want the pulled string to be in line with the tension direction, however, for off center strings, the racquet will rotate itself at an angle anyway. So it's impossible to completely avoid any friction on the grommet. And I think that's why we need a slippery grommet to transfer the tension to the string bed. (Another alternative would be to affix the racquet in 10 point fixed system and move tension head in any two dimension position, but that would probably be plain stupid.)

    Therefore, I think it is utmost important to replace the grommet when they are old and avoid any unnecessary angle so as not to wear down the grommet.

    My 2 cents.
     
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  17. verbouge

    verbouge Rookie

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    Related topic

    I'm undoubtedly displaying my own ingnorance here, but how can one learn if one is afraid to admit he doesn't know something?

    I string many Prince Speedport rackets of many models and flavors. I use the lockout on my Stringway ML100 T92 to string these sticks, and I generally like stringing them. I've searched high and low on the internet and on this site for the answer to a simple, basic question, but have yet to find it. I'm asking in advance so please be gentle, and if you have a link that answers it, kindly post it, make a little fun, and move on :)

    When I string I lock out my machine to the point that the string is touching the side of the port, but with the least exit angle possible. Sometimes, that exit angle is still pretty extreme, and there seems no way around it. Would it be better to pull the string through the dead center of the hole, if possible, even if it looks and feels weird, than to have it touching the side of the frame as it exits? It still would not be possible to do this every time, but it would make a difference in what I do. Also, is the boomerang tool or some other improvised device (Sharpie cap, etc...) superior to use than the lockout on my machine to string these rackets? Another thing: if the exit angle is great and there is no way around it, would it help to pull on the string with my fingers at the point of it exiting out the port in order to overcome the "friction hump" created by such a great angle?

    Oh yes, one last last last thing. The Prince website says that failing to string crosses from the top down voids the warranty on these rackets. There are many advocates of the 50/50 method, however, whereby the crosses start in the middle and go down and up equally, just as when stringing the mains. Do any of you do this? Should I make this whole question a separate thread??

    If this doesn't make sense, I'll try to re-explain, but if any of you track with this, can you help a guy out?

    Thanks,
    Dave
     
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  18. PBODY99

    PBODY99 Hall of Fame

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    50|50 works really well

    If you use the 50|50 patern for the Port rackets, you will find that it covers the angle of pull issue . I star in the middle, work to the top, tie off and complete the string bed down to the throat.
    Four years , over 100 re-stings, no problems.
     
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  19. Irvin

    Irvin G.O.A.T.

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    I have been playing with Prince ported rackets for a long time now. When I first started using the 2 piece 50/50 method I called Prince to see if it was ok and they told me it was ok. The racket I use requires the use of the first orange boomerang which Prince no longer has. I have the new Prince orange boomerang that will work in the racket but it is a little loose. If you watch my video you will see it.

    The boomerangs work great to string the Prince rackets if you use the right. They will hold the string in the pin hole grommets if you use the right one and hold the string in the correct position for you to clamp the string.

    Now let's talk about the 2 piece 50/50 method. It is different from the 50/50 method by the way. The 50/50 method is used for one piece. When stringing using the 2 piece 50/50 method you should always string from the center to the top first then the bottom half of the racket.

    Here is my video for using the 2 piece 50/50 method:

    http://www.youtube.com/watch?v=hJHwgzRR_gw

    Irvin
     
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  20. verbouge

    verbouge Rookie

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    Wow, great stuff, PBODY and Irvin! Very useful.

    Irvin, your video, especially, is super informative. You and others have convinced me that 50/50 is the best way to go with these sticks. From now on, that's what I'm going to do. It's just a matter of researching it thoroughly to make sure I don't mess it up.

    Thanks again,
    Dave
     
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