[Elecraft] DIY Hard-drawn copper wire

[Rick WA6NHC]

Even the smallest trees have substantial strength, species dependent of 
course (some have no tap root and only surface structure).  Bind LOW on 
the tree to make the pull closest to the anchor of the tree (the roots).

Vehicle frames are much stronger than a piece of typical (for antennas) 
copper wire, no worries.  Even the smallest car can handle the strain of 
a SMALL trailer (or passengers of large girth), BUT one should move 
slowly to not shock load the wire or vehicle AND (in addition to the 
excellent advice given) the safe zone is any place further away than the 
total length of the wire plus at least 20% (factor in stretching) since 
it may whip upon snapping.  While it's slightly possible that it could 
snap in multiple places and become airborne, distance is your friend.  
When in doubt, use another tree as a shield PLUS distance and safety 
equipment (hard hat, goggles etc.).

Rick nhc

On 2/11/2016 12:13 PM, Bill Frantz wrote:
> Trees are quite strong. When we do demonstrations by breaking 
> equipment during cave rescue classes, we use trees as anchors and a 
> truck with an electric winch attached to one tree. Some of these 
> things break at several thousand pounds force. (We measure the force 
> with a load cell.)
>
> The basics for tree anchors:
>
> (1) Make sure the tree is alive and healthy.
> (2) Wrap the tree with a tarp or heavy cloth to protect its bark from 
> damage.
> (3) Then wrap it with 2" nylon webbing at least 3 times. Use a water 
> knot to join the webbing. Leave the knot facing the load and pull the 
> rest of the loops out to a carabiner or quick link rated for the 
> expected load. This arrangement gives you a chance of being able to 
> untie the know when you are finished. (2" tubular webbing is rated at 
> 4000#. If you pull two loops, that is 4 strands and 16000#. Derate by 
> 50% for knots, bends around carabiners etc and get 8000#.)
> (4) If you are breaking things, such as #8 copper wire, cover them 
> with blankets to minimize the danger of having them snap through the air.
> (5) Keep everyone far enough away so flying wire won't hit them, or 
> keep them in a closed vehicle.
>
> 73 Bill AE6JV
>
> On 2/11/16 at 6:34 AM, edauer at law.du.edu (Dauer, Edward) wrote:
>
>> I wondered what 700 or 800 pounds of shear force would do to an 
>> automobile frame, assuming attachment to a suitable bolt somewhere.  
>> Or would the tree fall over first?
> -----------------------------------------------------------------------
> Bill Frantz        | Security is like Government  | Periwinkle
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