Is this scale good enough for calibration?

Discussion in 'Badminton Stringing Techniques & Tools' started by aril79, Sep 11, 2014.

  1. aril79

    aril79 Regular Member

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    scale.jpg

    hi BCers,
    i bought this scale to weight my luggage and since i already have it, i take the opportunity to check the tension of my klipper. to my surprise, i found that there are significant differences. 28lbs only read 26.5lbs and 32lbs only read 29lbs.
    being not satisfied with that i go through the manual and realize that there is a mention about the scale has to be used in vertical position.
    so now i'm released but still a bit confused. iirc, i have seen a number of pics/videos people using this scale to calibrate/measure their string tension (and that of course require the scale to be in horizontal position) and it apparently seems to be working fine for them.

    so the question, is the scale is really not suitable for calibration, OR my klipper is way off all this while?
     
  2. alex292

    alex292 Regular Member

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    I'm using the same scale and it gives pretty much the same results as the built in scale of my stringing machine (+/- 1lb max).
    The vertical position is due to gravity only working downwards and to measure the weight of something that is pulled down by gravity you obviously have to hold the scale vertical. The people writing the manual probably didn't expect someone using it for badminton stringing. As long as the scale is aligned with the force pulling on it, it should give you good results.
     
  3. Mark A

    Mark A Regular Member

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    These are perfectly good - they resolve better than a human can while playing with the racket:).
     
  4. Dekkert

    Dekkert Regular Member

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    I have the same scale and now I am wondering if the type of string has any influence on the reading.
    I bought it a year ago and tested my dropweight machine (Pro's Pro Pioneer) with a piece of BG65 string. When I put the weight on 10 kg (22 lbs), the scale measured slightly lower, around 9,7 kg. It did the same on 13 kg. So I thought the scale on my dropweight was quite good.
    2 weeks ago I tested it again and now it reads more than 11 kg when putting it on 10 kg. Reading over 15 kg when putting it on 14 kg. How would this be possible? I assume the setting of my machine doesn't change as is the scale of it. Could it be that the string used to testing it is important? Should I not be using a stretchy string but for example use a piece of rope instead for a more accurate reading?

    Someone who has an explanation?
     
  5. aril79

    aril79 Regular Member

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    i found it quite consistent, as i have measured it using several type of strings (leftover) in various tensions. in my case the problem is with the klipper itself. i found that only 24lbs is correctly calibrated. anything below that will be over-tensioned and everything above that will be under-tensioned
     
  6. Mark A

    Mark A Regular Member

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    The best possible string for testing tension is a scrap of Kevlar - it does not stretch. Ever:).

    Failing that, a scrap that's been pulled dozens and dozens of times is pretty good - all the stretch will have gone out of it.
     
  7. aiexrlder

    aiexrlder Regular Member

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    can anyone post a picture of how they set up the callibration? just want to check i'm doing it right
     
  8. DarthHowie

    DarthHowie Regular Member

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    I believe [MENTION=1]kwun[/MENTION] put up a video a while back on his badmintoncentral youtube channel. I may be able to put up a video this weekend of how i set mine up.
     

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