How off would the tension be with a +/- 10 degree drop weight arm angle?

Discussion in 'Stringing Techniques / Stringing Machines' started by flargosa, Feb 21, 2013.

  1. flargosa

    flargosa New User

    Joined:
    May 3, 2010
    Messages:
    98
    How much tension variation within +/- 10 degree angle of the drop weight arm? Just wondering, cause I usually string my poly at 52 lbs with a not so horizontal drop weight arm on some pulls. :(
     
    Last edited: Feb 21, 2013
    #1
  2. rich s

    rich s Hall of Fame

    Joined:
    Feb 18, 2004
    Messages:
    2,539
    Location:
    ATL
    the variation would be +/-1.5% of the selected reference tension

    your tension applied would be as low as 51.2# at +/- 10* from horizontal.



    EDIT..... the variation would be +0/-1.5% not +/- 1.5% as the tension cannot be higher than the reference tension.... the tension only goes down as the bar deviates from horizontal.
     
    Last edited: Feb 22, 2013
    #2
  3. darklore009

    darklore009 Professional

    Joined:
    Feb 19, 2012
    Messages:
    1,481
    Location:
    In Your Dreams
    shouldnt worry about it too much. it's off by a small percentage. not a problem at all
     
    #3
  4. flargosa

    flargosa New User

    Joined:
    May 3, 2010
    Messages:
    98
    Ok so +/-1.5% that is about 3% difference between the highest to lowest tension. Seems perfectly acceptable. Thanks.
     
    #4
  5. Clintspin

    Clintspin Semi-Pro

    Joined:
    Jan 29, 2005
    Messages:
    776
    #5
  6. Irvin

    Irvin G.O.A.T.

    Joined:
    Mar 15, 2007
    Messages:
    12,077
    Location:
    Marietta, Ga
    Trig was a long time ago but cosine = adjacent side / Hypotenuse.

    Cosine 10 = 0.839

    Adjacent is the length of weight from pivot

    Hypotenuse is the length it should be for true reading

    Therefore your are about 16% off. Stringing at 52 lbs you would end with (tension = 0.839 x 52) about 44 lbs tension.

    EDIT: You are much better off if you can keep the angle under 5 degrees then there is little error at all.
     
    Last edited: Feb 21, 2013
    #6
  7. rich s

    rich s Hall of Fame

    Joined:
    Feb 18, 2004
    Messages:
    2,539
    Location:
    ATL
    Irvin not sure if you hit the wrong button on your calculator or looked at the wrong column in a trig table but ... cos10 = .9848

    .985*52 = 51.2#

    cos^-1 (.839) is something like 33 degrees....

    unless you looked up the cos of 10 rads as opposed to 10 deg?

    rich
     
    Last edited: Feb 22, 2013
    #7
  8. Irvin

    Irvin G.O.A.T.

    Joined:
    Mar 15, 2007
    Messages:
    12,077
    Location:
    Marietta, Ga
    Oops I didn't use a calculator I used the Internet. I use the cosine 10 when I should have use the cosine 10 degrees. My bad. But still you are much better off keeping the angle under 5*. At 5* (cosine 5 degrees = 0.996) your error is a max of 0.2 lbs where 10* is 0.8 pounds.

    Not sure where this 10 degrees is coming from though. I know the Gamma X2 uses a ratchet with 36 steps I think that give you 10* (360/36.) But if you are let's say -8* below level and you take it up one step you should be around +2* so there should not be a problem getting under 5*. Or am I just wrong again? LOL

    EDIT: BTW thanks for catching me on that Rich
     
    Last edited: Feb 22, 2013
    #8
  9. rich s

    rich s Hall of Fame

    Joined:
    Feb 18, 2004
    Messages:
    2,539
    Location:
    ATL
    No problem Irvin...
     
    #9
  10. flargosa

    flargosa New User

    Joined:
    May 3, 2010
    Messages:
    98
    Thanks really glad to know +/- 10 degrees is still within acceptable range to me. Now I can worry less getting that arm perfectly horizontal knowing the tension variance very little.
     
    #10

Share This Page