Loading ...
Sorry, an error occurred while loading the content.
 

Sag Angle

Expand Messages
  • Scott Schroeder
    The other day I read Youngbloods excellent article on sag angle here: http://www.hammockcamping.com/Newsletters/2006/Jan2006.htm Yall are going to have to
    Message 1 of 3 , Jun 22, 2007
      The other day I read Youngbloods excellent article on sag angle here:
      http://www.hammockcamping.com/Newsletters/2006/Jan2006.htm

      Yall are going to have to check my math but if I got it right then to
      get the 30deg sag angle, all you need to do is hang the hammock taut
      and then let out another 10-15% rope/webbing to get 30 deg. I suppose
      if you wanted to get real precise you could mark the webbing/rope in a
      manner that would let you guesstimate better. And this is without a
      ridgeline of course.

      Now for the geeky stuff.
      In the paper he had 15 deg and 30 deg. I'll include 0 deg just for reference.
      Cos (0 deg) = 1
      Cos (15 deg) = .965
      Cos (30 deg_ = .866

      To get the length of rop

      Cos (30 deg) = distance from tree (x) / length of rope (y)
      to solve for y = x / 0.866
      or just the inverse of the angle's cosine (when comparing it to the 0
      Deg, nominal value of 1)

      if you take the inverse of those numbers you get
      1/ Cos( 0 deg )= 1
      1/ Cos (15 deg )= 1.036
      1/ Cos (30 deg) = 1.155

      So basically what that means is if the hammock line is perfectly flat
      it will have a nominal value of 1 and at 30 deg it is ~15% longer
      1.155. So if your hammock was lying flat on the ground and the
      distance from the hammock to the tree was 4 ft, then you would need
      4.6ft ( 4 * 1.155) of distance to get 30 deg sag angle. If you have
      it hung taut it probably isn't going to be at 0 deg so let's just use
      15 deg. Then the nominal value is 1.036. To get the needed distance to
      hang at 30 deg it's about ~10% longer than when hung taut.

      So my first question is, does that make sense? :)
      Second question is, am I correct? :))

      Scott
    • Dave Womble
      Scott... it sounds right to me. I think you can get an unloaded hammock hanging pretty close to the horizon if you tie it taut, close enough to not worry
      Message 2 of 3 , Jun 24, 2007
        Scott... it sounds right to me. I think you can get an unloaded
        hammock hanging pretty close to the horizon if you tie it taut, close
        enough to not worry about compensating for it.

        Dave Womble
        aka Youngblood

        --- In hammockcamping@yahoogroups.com, "Scott Schroeder"
        <schrochem@...> wrote:
        >
        > The other day I read Youngbloods excellent article on sag angle here:
        > http://www.hammockcamping.com/Newsletters/2006/Jan2006.htm
        >
        > Yall are going to have to check my math but if I got it right then to
        > get the 30deg sag angle, all you need to do is hang the hammock taut
        > and then let out another 10-15% rope/webbing to get 30 deg. I suppose
        > if you wanted to get real precise you could mark the webbing/rope in a
        > manner that would let you guesstimate better. And this is without a
        > ridgeline of course.
        >
        > Now for the geeky stuff.
        > In the paper he had 15 deg and 30 deg. I'll include 0 deg just for
        reference.
        > Cos (0 deg) = 1
        > Cos (15 deg) = .965
        > Cos (30 deg_ = .866
        >
        > To get the length of rop
        >
        > Cos (30 deg) = distance from tree (x) / length of rope (y)
        > to solve for y = x / 0.866
        > or just the inverse of the angle's cosine (when comparing it to the 0
        > Deg, nominal value of 1)
        >
        > if you take the inverse of those numbers you get
        > 1/ Cos( 0 deg )= 1
        > 1/ Cos (15 deg )= 1.036
        > 1/ Cos (30 deg) = 1.155
        >
        > So basically what that means is if the hammock line is perfectly flat
        > it will have a nominal value of 1 and at 30 deg it is ~15% longer
        > 1.155. So if your hammock was lying flat on the ground and the
        > distance from the hammock to the tree was 4 ft, then you would need
        > 4.6ft ( 4 * 1.155) of distance to get 30 deg sag angle. If you have
        > it hung taut it probably isn't going to be at 0 deg so let's just use
        > 15 deg. Then the nominal value is 1.036. To get the needed distance to
        > hang at 30 deg it's about ~10% longer than when hung taut.
        >
        > So my first question is, does that make sense? :)
        > Second question is, am I correct? :))
        >
        > Scott
        >
      • Dave Womble
        Opps... after I posted that message I thought about the hammock itself. Your method works if the hammock has a structural ridgeline but a hammock with a
        Message 3 of 3 , Jun 24, 2007
          Opps... after I posted that message I thought about the hammock
          itself. Your method works if the hammock has a structural ridgeline
          but a hammock with a non-structural ridgeline would be a problem
          because you would want its length to be increased by the same 1.15
          ratio, wouldn't you?

          Without the structural ridgeline you would have to add another math
          step, where you added half the difference of the length of the 0 sag
          angle hammock and the 30 degree sag angle hammock to each suspension
          line before you multiply the 1.15 ratio to the rope... I think.

          Dave

          --- In hammockcamping@yahoogroups.com, "Dave Womble" <dpwomble@...> wrote:
          >
          > Scott... it sounds right to me. I think you can get an unloaded
          > hammock hanging pretty close to the horizon if you tie it taut, close
          > enough to not worry about compensating for it.
          >
          > Dave Womble
          > aka Youngblood
          >
          > --- In hammockcamping@yahoogroups.com, "Scott Schroeder"
          > <schrochem@> wrote:
          > >
          > > The other day I read Youngbloods excellent article on sag angle here:
          > > http://www.hammockcamping.com/Newsletters/2006/Jan2006.htm
          > >
          > > Yall are going to have to check my math but if I got it right then to
          > > get the 30deg sag angle, all you need to do is hang the hammock taut
          > > and then let out another 10-15% rope/webbing to get 30 deg. I suppose
          > > if you wanted to get real precise you could mark the webbing/rope in a
          > > manner that would let you guesstimate better. And this is without a
          > > ridgeline of course.
          > >
          > > Now for the geeky stuff.
          > > In the paper he had 15 deg and 30 deg. I'll include 0 deg just for
          > reference.
          > > Cos (0 deg) = 1
          > > Cos (15 deg) = .965
          > > Cos (30 deg_ = .866
          > >
          > > To get the length of rop
          > >
          > > Cos (30 deg) = distance from tree (x) / length of rope (y)
          > > to solve for y = x / 0.866
          > > or just the inverse of the angle's cosine (when comparing it to the 0
          > > Deg, nominal value of 1)
          > >
          > > if you take the inverse of those numbers you get
          > > 1/ Cos( 0 deg )= 1
          > > 1/ Cos (15 deg )= 1.036
          > > 1/ Cos (30 deg) = 1.155
          > >
          > > So basically what that means is if the hammock line is perfectly flat
          > > it will have a nominal value of 1 and at 30 deg it is ~15% longer
          > > 1.155. So if your hammock was lying flat on the ground and the
          > > distance from the hammock to the tree was 4 ft, then you would need
          > > 4.6ft ( 4 * 1.155) of distance to get 30 deg sag angle. If you have
          > > it hung taut it probably isn't going to be at 0 deg so let's just use
          > > 15 deg. Then the nominal value is 1.036. To get the needed distance to
          > > hang at 30 deg it's about ~10% longer than when hung taut.
          > >
          > > So my first question is, does that make sense? :)
          > > Second question is, am I correct? :))
          > >
          > > Scott
          > >
          >
        Your message has been successfully submitted and would be delivered to recipients shortly.