Debate: 2 vs 6 Point

Discussion in 'Stringing Techniques / Stringing Machines' started by prostaff18, Jun 25, 2008.

  1. Mansewerz

    Mansewerz Legend

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    Took it off the machine. Can't accurately measure when it's mounted. It was fully strung (I'm not hoping to crack a frame by having just the mains in!)
     
    #51
  2. Bud

    Bud Bionic Poster

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    Yeah, we're talking about the racquet... still secure in the machine... with the mains strung only.

    If your mains are strung significantly higher than the crosses (or if they are a different material like poly or kevlar), it's possible the racquet head is shorter.
     
    #52
  3. mellofelow

    mellofelow Semi-Pro

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    I don't claim to be a historian but modern era of stringing machine pretty much started by Ektelon. 30 years ago it was a solid hunk of steel, 2 pt mount, gliding bars and crank tensioner. Think about the evolution of machines since then, what has changed? Pneumatic tensioner, electronic tensioner, swivel base clamps, floating clamps... etc. No matter which tensioner is used, as long as they're calibrated to the exact tension and the string is clamped within a second or two... there are no differences in the result. As for the clamps, regardless which type, as long as there are no movement under tension, again... no differences.

    So what is it then? Since you already confirmed the great debate about head shape deformation under load on 2 pt mounts, the only variable from any of the discussion obviously is that the 6 pt mounting system greatly enhances the frigidity of racquet head shape during stringing. That, my friend... is the only innovation that has improved and prolonged the life of your precious racquet in the last few decades. Anything else is mere luxury.
     
    #53
  4. Mansewerz

    Mansewerz Legend

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    Yea, but 1/16th of an inch is pretty much nothing. It's nothing to worry about. .1" is acceptable (from what Gamma Tech aka Bret told me)
     
    #54
  5. Bud

    Bud Bionic Poster

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    I confirmed that any deformation is barely noticeable, if at all... on a large-headed very flexible racquet (which is a worse case scenario and why I chose the racquet to test). Deformation on a mid/mid+ or smaller headed racquet will be even less significant.

    In your diagram, you have the area at 11 oclock going inward. That wasn't the case. There is some slight outward deformation that starts between the 10 and 11 o'clock region and increases until 9 o'clock. The deformation goes outward, not inward.

    The only evidence of inward deformation was near 5 o'clock where the bridge, head and neck meet. That area (approximately 1.5" along the curve that transitions into the neck) deformed inward very slghtly (about .06").

    So, basically, your diagram is incorrect. All 3 arrows should be pointing outward. The neck, below the bridge deforms slightly inward (.06").

    Now, I'm going to research the 6-point mounting system and which forces it's designed to minimize. From what I can surmise, you assumed those forces were pointed inward and the 6-point was preventing the racquet head from collapsing inward. That's not the case.
     
    #55
  6. mellofelow

    mellofelow Semi-Pro

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    How the heck is a piece of oval graphite/composite positioned stationary at 2 points expand all around from 11 to 8 positions? It's not a WART! The volume increase at 9 must be displaced by somewhere else. Furthermore, a frame in the hands of more seasoned player, the 2 areas that get abused the most are 10 & 2. This is where you jam the racquet into the pavement on half volleys and/or drag the frame for 2 to 3 feet in full speed and full stretch. Therefore, you should do all you can to prevent anymore stress to those vulnerable points during stringing. My point is that the 6 pt mount provides that insurance over the 2 pt.

    I'm done with this nonsense. I have both Ektelon (2pt) & Eagnas 910 (6pt) in my garage so I'm not speaking in theory.

    Anyone else thinks I have my head in the sand, feel free to speak up.
     
    #56
  7. Bud

    Bud Bionic Poster

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    Hey guy, didn't mean to upset your applecart. If you think about it, though, it does make sense.

    Here is what happens: the forces from the tensioned mains pull inward... but, since the racquet is constrained from collapsing inward (from the mounts at 12/6 o'clock), it must bulge. It bulges the greatest at 9/3 o'clock (where no mounts constrain the racquet) and tapers off right before the mounting system (at 12/6)

    Looking at a 6-point mounting system, I notice the mount prevents the racquet head from bulging outward... which is consistent with what I discovered. This is also the reason that some think the 6-point mounting system may be more detrimental to the racquet than the two-point system. The 6-point system doesn't allow the racquet head to expand/bulge (assuming the mounts are tight and touching the frame)... and thus puts a large amount of force on the racquet head directly at the additional mounting locations (10/2).
     
    #57
  8. Bud

    Bud Bionic Poster

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    I'm also assuming, based on my experiment that there are no stringing machines on the market with outside mounting at 12/6 and 9/3... since that would not allow the racquet to bulge at all in the area that experiences the most deformation (9/3)... and would probably end up snapping the racquet at 10/2.
     
    Last edited: Jul 10, 2008
    #58
  9. Bud

    Bud Bionic Poster

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    As I said, we're NOT talking about racquets that are fully strung and off the machine. This is about the stresses on the racquet head while the racquet is STILL IN THE MACHINE with the mains strung ONLY.

    You keep referring to the racquet after it's strung and off the machine.
     
    #59
  10. mellofelow

    mellofelow Semi-Pro

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    Bud, bud, bud... that statement was a Dud. The only thing it make any sense was you contradicting yourself.

    [​IMG]

    Wrong again!! Here again is the machine I used in the junior days. It's a piece of #^%$ work &%)! but got the job done nicely. And no!!! It would NOT break the racquet at 10/2. The effect is absolutely opposite. Having firm support at 9/3 creates the strongest structural design known on earth... AKA.. the Roman arch.

    [​IMG]
    http://en.wikipedia.org/wiki/Arch

    It's an open forum... but I really question your expertise to advise others in this subject.
     
    #60
  11. WildVolley

    WildVolley Legend

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    Never say no machines. The True Tension machine I recently received has inside supports at 12/6, and outside supports at 9/3. From the measurements from a professional stringer at the GSS site, this precise setup led to the least racquet distortion of any of the mounting systems used on professional stringing machines, at least when measuring length and width. You be the judge whether that is a good or bad thing?
     
    #61
  12. onehandbh

    onehandbh Hall of Fame

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    Ha ha ha. No way that a 6 pt mount is worse than two unless
    all 6 mounts are all adjacent to each other at 12 o'clock,
    making it essentially a ONE point mount. Go check out a book
    a physics book on mechanics and you'll soon see why 2 < 6.

    btw, every racquet I've ever broken (7 or 8?) except for one,
    has always been at around 7:30 or 4:30 and all from
    overheads. I think those two positions are probably where
    the racquet faces the most stress since it's right before
    the intersection with the throat.
     
    #62
  13. Mansewerz

    Mansewerz Legend

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    Probably, and most likely the same reason that stringing top to bottom is recommended.
     
    #63
  14. jim e

    jim e Hall of Fame

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    If you look at the stringing instructions for the new Head crossbow racquets, if you have a 6 point, you mount and string as normal, but with a 2 point or 4 point, Head has different mounting instructions, and a different stringing pattern, an ATW pattern, utilizing 2 piece, stringing 6 mains on one side 1st! something that you would typically never do!(I'm sure that puts undue stress on their racquets, they probably came up with that as an alternative as to not allowing them to use a 2 point or 4 point machine, as that would certainly tick off a good # of folks.)
    Anyways, I'm glad I have a 6 point, there are a few hitting with those racquets around here now, and I'm sure they will be making there way to me at sometime. I just contacted Head to send me the crossbow adapter, which they claim is mandatory on all machines, as it protects the 12 oclock position of the racquet, they said they are out of them already, and will be a few weeks before they can send me any. One person here already told me he threw out that little thing that came with his racquet! I really don't know why they gave it to the racquet purchaser as most do not even string them, but it should be avail. to all stringers.
    This in time will give YUlitle another pattern to show all you good folks here with a 2 or 4 point machine, to add to his expanding list of videos don't you think?
     
    Last edited: Jul 10, 2008
    #64
  15. Bud

    Bud Bionic Poster

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    First, enough with the child talk and the lousy rhymes. It's not useful and makes you appear arrogant. It seems you'd be more humble since my experiment has already proven your original assumption incorrect.

    Nest, a roman arch is made of rigid, segmented, masonry units... not flexible graphite and fiberglass. So, when you're making an analogy, please remember the materials you're dealing with and the intent of the structure. It's akin to your other silly analogy comparing a bow to a racquet head.
     
    Last edited: Jul 10, 2008
    #65
  16. Bud

    Bud Bionic Poster

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    Exactly! The racquet bulges outward at 9 and 3 (by about .5" in my test) and outside supports would place an amazing amount of stress at 9/3. That's why there are inward supports! Please read the entire post and you'll find it's consistent with the results of my experiment.
     
    #66
  17. Bud

    Bud Bionic Poster

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    How about you prove what you say by a real world test, pictures or other evidence. I conducted a lengthy experiment and observed where the racquet deformed. What have you done?

    In addition, please find where I stated that a 6-point mounting system is worse than a 2-point.
     
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  18. WildVolley

    WildVolley Legend

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    Yes, I reread your post. The True Tension is a 4-point system, but not all outside supports. Do any racquet stringers have outside supports at 12/6?
     
    #68
  19. Bud

    Bud Bionic Poster

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    Here's the bottom line. If you have something valuable to add to this thread, then contribute. But, so far you're more concerned with proving me wrong than searching for the truth.
     
    #69
  20. Bud

    Bud Bionic Poster

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    Man, thank you for taking the time to understand my post. It can be really frustrating here with threads like this. I performed the experiment because I originally had no idea as to the real forces on a racquet head. I was quite surprised by the results... but the results are completely consistent with modern stringing machine design. I should have know I'd be attacked by some who are more interested in being right than searching for the truth.

    Like you, I'd also like to know if there are any machines currently produced that constrain the racquet on the outside of the frame at 9/3. This is a machine I'd definitely steer clear of if one is still produced and sold.
     
    Last edited: Jul 10, 2008
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  21. tenisjugador

    tenisjugador Rookie

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    What happens if, for six-point mounting, a grommet is blocked? How do you put the string through?
     
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  22. YULitle

    YULitle Hall of Fame

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    Better mounting systems are designed to eliminate this issue.
     
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  23. iplaybetter

    iplaybetter Hall of Fame

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    behind you, but i have to be somewhere else by the
    you must work around it, the method for doing this is dependent upon the specific machine
    but usually with enough stubbornness you can get around the mount
     
    #73
  24. tenisjugador

    tenisjugador Rookie

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    Okay, so it's not like its totally impossible and you have to stop.
     
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  25. iplaybetter

    iplaybetter Hall of Fame

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    behind you, but i have to be somewhere else by the
    no, but going from the 6pt on the revo to the 4pt prince, i have found it to be very nice not to have to wory about it
     
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  26. jim e

    jim e Hall of Fame

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    On my 6 point, it never is an issue at all. The mounts do not totally block a grommet hole, the way the brackets are mounted you can always get the string through without a problem, even if the bracket is right over a grommet hole. This should not even be an issue.
     
    #76
  27. JamesBond

    JamesBond Rookie

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    It's nice to see that someone else is defending the 5 point inside mounting system From Stringway. I have a Stringway ML.100 and have been using this system for many years, it really is remarkably efficient and once you get used to it, very easy to use.

    I'm no expert on the theories of deformation, but I do think that for the frame the problems of stress are a more important element to consider. Absence of deformation doesn't mean absence of stress. When I notice is that the frame never moves when I put in the main strings, but the sides of the frame do deform a little when I put in the crosses. I would imagine that this is normal.

    I think that the outside supports on a 6 point system must be applying serious pressure to the side of the frame to stop it deforming, but at the same time wouldn't this be creating a stress point on the frame? How often do frames break at the 10 o'clock and 2 o'clock zone which is precisely where the side supports are located ??

    What is really important for me is that the frame never gets jammed in the racquet supports. If I string a series of the same frame with my SW I never have to adjust the supports, unstrung or strung it slips into place and lifts out exactly the same way, its really great.

    I do think that it takes a little longer to install the racquet than with a self centering 6 point system, for a series that's not so, but if you change the settings every time it's a bit slower. Once you get the knack of it, it's like everything else in stringing, it's HABIT, and changing habit's is not always evident.

    Just my 2 cents worth, if anyone cares to comment I will happily reply.
    Thanks for the topic, it's nice to participate in an interesting conversation.
    JB.:neutral:
     
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  28. SW Stringer

    SW Stringer Semi-Pro

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    " . . . I'm no expert on the theories of deformation, but I do think that for the frame the problems of stress are a more important element to consider. . . . "

    One of the few honest people who prefaces his opinion by admitting he's no expert. This debate amongst frame designer wannabees is basically a waste of time . . . points and counterpoints are made by people who are usually far from being expert. Who are the experts on frame deformation and carbon composite structure design? Why I believe many if them may actually be gainfully employed by Wilson Sports, Prince, Head, Babolat, Slazenger, etc. It would be their job to guarantee that their frame can pass the rigors of being strung on a two point mount machine, since that is the most prevalent type of machine available and it presents a worst case condition that the designers must meet before the frame can go to production. Something they learned in Engineering Structures 101.

    In my opinion any racquet properly mounted in most any two point mount machine and properly strung will function as the designer intended. And I dare anyone to cite a published engineering study {or USRSA published study} that proves otherwise.

    To sum it up, the difference between two point mount and four, six, internal, external etc, etc, etc, is purely cosmetic, and user preference. If you like it and it makes you feel good about your machine purchase then go for it. Just rest assured that someone who IS expert in frame design has already guaranteed it will work on your machine, reliably, for many years to come.
     
    #78
  29. SunDog

    SunDog Rookie

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    JB,

    What I have found in doing the distortion measurments is that the frame sides do move quite a bit while installing the mains. I placed a small piece of tape at 12, 3, 6 and 9 o'clock and put a small ink dot on each to keep the measurment location constant. If you measure the distance btw dots at 3 and 9 pre and post stringing of the mains - you will witness a significant amount of movement - even without the distance btw 12 and 6 changing much at all. On the SW machine - the distance btw 3 and 9 returns to effectivly the same upon completion of the crosses for the framest that I have measured.

    Other folks have posted similar measurement activities for the Star 5 and Prince 5000 (i believe) and the net SW results were the closest to the original dimensions.
     
    #79
  30. Bud

    Bud Bionic Poster

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    One thing to remember though... if the frame is showing no deformation, based on the multi-point mounting system (with mains installed only)... the arms of the mounting system are preventing the racquet from deforming. Therefore, there is an amazing amount of force at the localized points where frame meets mounting arm(s). I think this can be just as detrimental, if not more so. Racquets are meant to flex from the stringing process and preventing it may not be a good thing.

    I noted this in one of my posts above (concerning outside mounting) after measuring the deformation on an X-2.
     
    #80
  31. aussie

    aussie Professional

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    For what it's worth, this is from the KlipperUSA website:

    "Is the 2 point mounting system of the Klippermate strong enough or do I need a 4 or 6 point system? The turntable of the Klippermate is made out of solid steel. We guarantee you will never damage, crack or distort a racquet on the machine as long as you follow the proper mounting procedure. This strong 2 point system will protect any racquet no matter what tension its being strung at. The Klippermate's turntable allows the natural flexing that a racquet must go through as its being strung. Past research has shown that some 4 or 6 point mounting systems could damage the racquet internally by holding the racquet too rigid."

    Marketing spiel no doubt, but I have followed up on this with Klipper and they were able to go into far more detail to support this statement. They are adamant that if the frame is mounted securely (the posts pulled out firmly against the frame and the frame plates screwed down firmly) there will be no damage to the frame. My experience so far (1 racquet I've strung about 15 times on the K'mate) is that I have no reason to doubt Klipper's assertions.
     
    #81
  32. TenniseaWilliams

    TenniseaWilliams Professional

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    I am not sure racquet protection is the only issue here .

    Would anyone agree that the the six point mount will produce a different result than a 2 pt? Assuming top down stringing, wouldn't the top crosses be tighter on a mounting system that didn't allow as much flex?
     
    #82
  33. onehandbh

    onehandbh Hall of Fame

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    Another analogy, to help the 2 pointers see the light.
    If you had to lie on a bed of nails, would
    you rather lie on a bed with 2 nails or one with 1500 nails?

    The larger number of nails helps to distribute the force so that
    each nail has less pressure applied to it.

    On a stringer, the forces decrease at each point as the
    number of points approach infinity. What would work best?

    Or put another way. Which do you think would be better.
    A 2 point (or 4 or 6) or a steel mold that basically wraps
    around the entire racquet and has small holes to allow
    stringing. Basically, this would be an infinite point machine.
    Do you still think 2 points is better? :) If you do, then
    I have some property at Glengarry Glen Ross you might
    be interested in purchasing...
     
    #83
  34. Bud

    Bud Bionic Poster

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    Please find where I claimed to be some sort of expert on this subject. Furthermore, I'm not 'advising' anyone... we are all free to read through anyone's and everyone's posts in the TT Forum and draw our own conclusions about the information that is posted.

    If you disagree with something I posted, address that rather than taking a potshot at my 'expertise'.
     
    #84
  35. Bud

    Bud Bionic Poster

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    Go re-read the entire thread. You're analysis is flawed and doesn't consider the point stress placed on the frame, at certain locations, as it presses against a mount during the main stringing process.
     
    #85
  36. onehandbh

    onehandbh Hall of Fame

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    My bad, you believe that a 2 point mount is equal, not better than a 6 pt
    system.
    Being that you are in San Diego, if you have time, go visit some of the physics
    professors or TA's at UCSD and ask them this question. They would probably be
    able to give an analysis that would settle the debate.

    btw, an even better system would be in the infinite internal mold -- bascially
    a mold on the inside of the racquet touching every point of the frame.
     
    Last edited: Aug 14, 2008
    #86
  37. LttlElvis

    LttlElvis Professional

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    I think you analysis is flawed too. Sure a 1500 nail bed has more support than 2 nails, but we are talking the differences between 2 pt an 6 pt racquet mounting.

    I totally agree that in infinite internal mold theoretically has to be the best system available. However not practical due to different shapes of racquets.

    What I like about the 2 pt systems like the Neos and Gamma 6004, is the 4 internal mounts. That combined with the press down mounts on the head and throat. That is hardly 2 pts.

    I am not an engineer or an MRT, but this is just my opinion: What bothers me about the 6 pt floating mount is when doing cross strings. I think the 6 pt mounts are great support during the mains. During the crosses, I am not so sure. As the racquet compresses, those side mounts really don't do a thing and the racquet is only being supported by the tiny internal supports at 6 and 12 o'clock. Probably not a big deal, but I just question it.

    The type of 2 pt mounting that the NEOS uses has been around a long time. It was good for stringing wood racquets at 55 lbs. Racquets now a days are even stronger, and what are we string them at? 55 lbs - 62 lbs. Not much change, and racquets sure are a lot stronger.

    Once again, I am not sure because I am not an engineer, but I would take a good 2 pt mounting over a 6 pt floating mount. I wish there was a mount that had the Gamma 6004 head and throat mount along with 4 side supports. That would be ideal for me.
     
    #87
  38. onehandbh

    onehandbh Hall of Fame

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    I wasn't claiming that it's like 2 nails vs. 1500. Just that
    more is better. I haven't made the actual calculations but
    I would guess that 4 internal mounts are sufficient.
    Each additional mount after 4 or 6 is probably not worth
    the additional cost and difficulty in stringing.
    In my own observations and those of people that string
    on a neos, I've never heard of a racquet being broken while
    being strung.

    I think if you properly mount it, then you should be fine.
    Having a large difference in tension between the mains and
    crosses is probably harder on the racquet.

    During the stringing of the crosses, the mounts being away
    from 9 & 3 will help a little. Plus there is the tension
    from the mains. Internal mounts are still better.


     
    #88
  39. Bud

    Bud Bionic Poster

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    Based on the experiment I conducted with a racquet on an X-2, here are some of my conclusions:

    1. A 2-point mount is an adequate system for stringing tennis racquets and is not detrimental to the frame. Frames are designed and engineered to expand and contract to some degree with the assumption they will be strung on a 2-point stringing machine.

    2. A 6-point mount is good, too... as long as the mounts at 10/2 and 8/4 do not prevent the racquet frame from bulging/expanding outward while stringing the mains.

    3. Any mounting system that prevents the frame from expanding outward during the main stringing is probably not the best mounting system.

    4. A mounting systems that restrains the frame in the vertical direction (perpendicular to the stringbed) at 10/2 and 8/4 (while not restricting frame expansion, outward) is the best mounting system. This prevents the frame from lifting or torqueing when stringing the crosses.
     
    #89
  40. Bud

    Bud Bionic Poster

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    I agree that internal mounts are best.
     
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  41. Bud

    Bud Bionic Poster

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    Nice mounting system

    I really like the simple and effective mounting system of this Stringway machine.

    1. It doesn't restrict frame expansion.

    2. It restrains the frame in the vertical direction (perpendicular to stringbed).

    3. Allows free access to all grommet holes.

    However, on the racquet below... I would have placed the restraining mounts (near the throat) so they were restraining the head of the racquet, as opposed to the throat.


    [​IMG]


    [​IMG]


    [​IMG]


    [​IMG]
     
    Last edited: Aug 14, 2008
    #91

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