main support deforming under load

Discussion in 'Badminton Stringing Techniques & Tools' started by konstancij, Jan 12, 2021.

  1. konstancij

    konstancij Regular Member

    Joined:
    Mar 23, 2017
    Messages:
    82
    Likes Received:
    34
    Location:
    Riga
    Hi. while training my skills with new machine, I have found that when mounting a racket, I need to deform it with main supports by 3-4mm longitudal in order to get exactly same dimentions in the end. Otherwise, racket head comes out shorter by these same 3-4mm, no matter how much % I add to crosses to compensate.
    Wondering, why is it happening, I measured distance between metal main support parts, and found, that under full mains load, they are closer to each other by 4.5mm, i.e. deforming under load.
    Question to other practioners of stringing zen, what king of deformation, if any, you can measure on you machines?
     
  2. konstancij

    konstancij Regular Member

    Joined:
    Mar 23, 2017
    Messages:
    82
    Likes Received:
    34
    Location:
    Riga
    why there is so little interest in this topic? May be it is my english or I failed to describe the the problem...

    today, having some free time, I found a way co completely eliminate movement of adjustable part of main supports. That was about 2-3 mm. My machine have 8 hex screws, and i need to adjust 4 of em, every time. Interesting, there is nothing in manual on these screws, and it is kind of strange design.

    So, but, I still measure movement of central supports, because torrent and baseplate are deforming by about 3-4 mm. So my racket that is 23.85 cm without strings needs to be mounted to 24.1, to become 23.7 when mains are pulled, and finally become 23.9 with crosses pulled. I would appreciate feedback, on is it what normally happen and you observe on your machine. I think that 0 movement is only achievable on something with ring support, like merco b-200.
     
  3. SnowWhite

    SnowWhite Regular Member

    Joined:
    Oct 13, 2018
    Messages:
    113
    Likes Received:
    121
    Location:
    London
    I don't think anyone who has viewed your post really has a solution to your problem. If the supports deform when under tension, that's a problem with the machine. It shouldn't happen, and no stringing technique is going to fix the machine. So your options are to make do by, as you say, adjusting the supports to account for the change, or to get better supports or a better machine. I don't have a great machine, but it does the job and doesn't deform under load.

    See if you can't find a user manual for your specific machine online to see if there is anything you can do. If it's loose in the joints then you can probably tighten it, maybe get new bolts and nuts, or threadlocker in some strategic places (I don't really know how your machine is put together). If all the joints are tight and it really is the baseplate that's deforming, I don't think there is much you can do.
     
    michael5098 and s_mair like this.
  4. kwun

    kwun Administrator

    Joined:
    Apr 24, 2002
    Messages:
    40,328
    Likes Received:
    1,363
    Occupation:
    BC Janitor
    Location:
    Santa Clara, CA, USA
    it is not really something that can be solved easily. say if you are stringing 25lbs tension, there are 22 mains strings, that's 550lbs of force pulling on that one support column. it will take a very well built, and thus very heavy and expensive machine to not even deform at all. but as you mentioned, when cross strings are tensioned, it will even out the force and elongate the racket back to "normal".
     
  5. fanfaron

    fanfaron Regular Member

    Joined:
    Jan 14, 2015
    Messages:
    234
    Likes Received:
    36
    Location:
    montreal
    My machine when pulling the mains the racket deforms, after the cross are pulled it evens out. It's weird that yours doesn't do that. But we all have to work with shortcoming of our machine. It's rare to have a perfect machine. As far you can fixe the problem I think it's good. My machine is two points machine, I too elongate a little bit the racket. I have the old Prince 3000. I remember something worse happen to me on some racket. On some weird brand racket, it kinda twisted when removed from the machine. I don't know if it's the racket is not strong enough for the tension... Happen me twice on the brand Sotx...
     
    #5 fanfaron, Jan 18, 2021
    Last edited: Jan 18, 2021
  6. konstancij

    konstancij Regular Member

    Joined:
    Mar 23, 2017
    Messages:
    82
    Likes Received:
    34
    Location:
    Riga
    Hmm if Prince 3000 by toyo-zuki deforms too, then perfect machine hardly exists. however, I have several ideas for future tuning.
     
  7. fanfaron

    fanfaron Regular Member

    Joined:
    Jan 14, 2015
    Messages:
    234
    Likes Received:
    36
    Location:
    montreal
    It does... but 99% of the job the racket comes back the same shape. So I stop worry about it. In the beginning I was very obsessed. But Now I concentrate to the flow. Like I make sure When I weave I go under first. that way I never missweave. You know little stuff like that. Always trying to go little bit faster.
     
  8. kwun

    kwun Administrator

    Joined:
    Apr 24, 2002
    Messages:
    40,328
    Likes Received:
    1,363
    Occupation:
    BC Janitor
    Location:
    Santa Clara, CA, USA
  9. konstancij

    konstancij Regular Member

    Joined:
    Mar 23, 2017
    Messages:
    82
    Likes Received:
    34
    Location:
    Riga
    Yes, exactly this design, i find tempting to try. Unfortunately, I do not see possibility to order the ring without entire machine. Alibaba seller of alpha machines is willing to sell complete machine only.
    Also there is something to consider. Almost 100% of pro machines are of U design. This mean, that it is considered optimal and may be slight deformation is necessary to spread the load over all 6 points of support system. In absolutety rigid system, main supports will bear almost all load and that may increase risk for racket breakage.
     
  10. kwun

    kwun Administrator

    Joined:
    Apr 24, 2002
    Messages:
    40,328
    Likes Received:
    1,363
    Occupation:
    BC Janitor
    Location:
    Santa Clara, CA, USA
    stringing machine design isn't exactly a highly innovative design area. a lot of these design have a lot of legacy elements to it.

    side support in itself, is not optimal in any shape or form due to what you said. it is prevent a secondary effect which is for the racket to deform first before it has any effect.

    having 100% pro machine using that design don't necessarily mean it is optimal. it just mean ppl are used to it, and perhaps the ring shape design has other issues that the pros won't like. I can think of a few off the top of my head. firstly, it is harder to adjust, and then there are extra stuff to get in the way when the first priority for pros is speed, and then to use such a machine pro might have to change the tensioning pattern that they have been doing for decades, probably won't go down so well either.
     
  11. konstancij

    konstancij Regular Member

    Joined:
    Mar 23, 2017
    Messages:
    82
    Likes Received:
    34
    Location:
    Riga
    well, I continue my quest for zero deforming machine. I just tried very simple and cheap tool, you can see the idea from the picture. This introduced some additional difficulties for stringing, but nothing serious and i think I will enchance it. But, the result is completely what I wanted: I mounted the racket with almost 0 presure from supports, only deforming it by 0.5 mm, and in the end the racket dimentions are perfect. Just as unstrung. load 11.5/11.75 kg, also very moderate addition to the crosses.
     

    Attached Files:

    Super85, s_mair and kwun like this.
  12. kwun

    kwun Administrator

    Joined:
    Apr 24, 2002
    Messages:
    40,328
    Likes Received:
    1,363
    Occupation:
    BC Janitor
    Location:
    Santa Clara, CA, USA
    very nice. aside from the slot, did you put in other measures to prevent the rod from slipping?

    How are you adjusting the length? I see some hex shape on the other side. some sort of threaded tube or nut?
     
    konstancij likes this.
  13. kwun

    kwun Administrator

    Joined:
    Apr 24, 2002
    Messages:
    40,328
    Likes Received:
    1,363
    Occupation:
    BC Janitor
    Location:
    Santa Clara, CA, USA
    A design is just a combination of compromises.

    Your design is perfect in terms of eliminating compression between 12/6 o'clock position. You got 0.5mm but if the machining is more precise it can be 0mm. Afterall, no mortal strength should be able to compress a steel rod in that configuration. However, it doesn't solve all problem and also create a few. It helps but doesn't solve problem with movement of the other supports (2/4/8/10 o'clock). That will depend on the rigidity of the swing arms. Also, this blocks the free moment of the hands around the center mains and it blocks hands from threading cross strings.

    If we limit ourselves to badminton only, the Alpha solution has a better set of compromises. It doesn't restrict hand movements, it is very rigid for all supports (but probably not as good as a direct rod). It is configured with the traditional 6pt support, but I don't see why it cannot be extended to even more complete set of supports.
     
  14. konstancij

    konstancij Regular Member

    Joined:
    Mar 23, 2017
    Messages:
    82
    Likes Received:
    34
    Location:
    Riga
    no, it does not slip. I first mount the rod to fit slightly tight. and then the pressure from mains holds it very well. In the end, the rod again can be removed just by fingers.

    there is a long nut for adjusting, another rod, very short, with similar slot.
     
  15. Mark A

    Mark A Regular Member

    Joined:
    Sep 2, 2005
    Messages:
    7,032
    Likes Received:
    569
    Location:
    St Helens, UK
    Try this: don't stretch the racket, and after you've pulled the first two (central) mains, tighten the 6 o'clock support - it might move. Then pull the second main on each side and try tightening the 12 o'clock support - that might also move, a bit less. Check the 6 o'clock again after the third mains, but that should be it.

    There is often some play in the 12/6 supports until the racket experiences some compression, and load spreaders introduce even more play as they deform.
     
    speCulatius and s_mair like this.
  16. konstancij

    konstancij Regular Member

    Joined:
    Mar 23, 2017
    Messages:
    82
    Likes Received:
    34
    Location:
    Riga
    I think have not observed any freeplay between main supports (6 and 12) and mounted racket in my setup, have to check. ..
    but what is reasoning behing this technique? If a racket head has lenght, say 23.8mm and we mount it without any free play, then the distance between supports will be also 23.8. Then later, when we tightening main supports, we only increasing distance inbetween to, for instance, 24.0. This is the same as deformation while mounting, is't it?
     
  17. s_mair

    s_mair Regular Member

    Joined:
    Oct 10, 2013
    Messages:
    4,388
    Likes Received:
    2,727
    Location:
    Germany
    Two effects:
    1) with the first two mains tensioned, the racket gets pulled deeper into the load spreader at the top
    2) it will compensate some of the deformation that might be happening in the main supports under load

    Give it a try, I'm sure you will notice some play once the first 2 mains are pulled. I've implemented that step a while ago after Mark mentioned that and I never had any issues with the head shape ever since - even with a square tension ratio. I have never checked the top support after the first 4 mains though.
     
  18. Mark A

    Mark A Regular Member

    Joined:
    Sep 2, 2005
    Messages:
    7,032
    Likes Received:
    569
    Location:
    St Helens, UK
    It's something I used to do when I had loadspreaders at both ends. Less of an issue if you go bareback at the 6 o'clock.
     
    s_mair likes this.
  19. Mark A

    Mark A Regular Member

    Joined:
    Sep 2, 2005
    Messages:
    7,032
    Likes Received:
    569
    Location:
    St Helens, UK
    The supports themselves may be moving, or the loadspreaders may be compressing.
    Or both.
     
  20. Mark A

    Mark A Regular Member

    Joined:
    Sep 2, 2005
    Messages:
    7,032
    Likes Received:
    569
    Location:
    St Helens, UK
    The Koreans asked for stretched rackets the last time Victor sent a team to the All England... they must be used to bad machines and/or inattentive mounting...
     
    s_mair likes this.

Share This Page