Hi all,
Here is the contraption i have got a steel shop to fab.
http://picasaweb.google.com/wlanddx/TreeMountFixture?feat=directlink
Question:
In one of the photos, i have marked cutting points in red color. Should i
cut or not?
The objective is to reduce weight. Cutting the gussets will reduce the
weight by at least
14lbs. Don't know about the gain in weight by cutting a section of the
round tube for the swing gate.
I plan to mount a TA-33 or A3S.
I am getting ready to galvanize this contraption and will need to make a
decision (cut or no cut?) in
the next few days.
Here are the details.
1. Swing arm - 1/8" thick steel and weighs about 22 lbs.
2. The rotor/bearing mount - 3/8" thick steel and weights about 84 lbs.
3. In addition, gotta add the weight of the rotor (say 20lbs ??) + HF yagi
(30lbs max)
Since this will be up on a tree and will be secured using
a) Multiple lag bolts (2 to 6 perhaps).
b) There are 2 nuts welded at the top and bottom of the fixture. An EHS
steel cable
that is used to guy towers will be run around through a couple of 2x4
piece of wood
with holes drilled in it for use as spacers. Then a turnbuckle will be
used to tighten it.
The turnbuckle will be adjusted yearly to let the tree grow around.
c) In addition, 2 eye bolts will be installed, one above the fixture on the
opposite side of the
bracket, a few feet above and below it. A safety steel cable will be
strung through the eye bolts. This will
act as backup in case the tree breaks off at the top or the primary cables
gives away.
At any rate, i don't want this to come down. If it were to, its gotta come
down when the tree
comes down. In all, there will be 4 cables around the tree to secure it.
d) Annual inspection by a tree climber.
e) This goes in between the branches of a tall pine at the 50ft level. At
the
mount point, the trunk is about 1.5 to 2 ft wide. This is a type of
pine tree that cannot be topped.
All painted with camo paint to blend in.
Any comments? suggestions?
73s
<name/callsign withheld to avoid detection by neighborhood busybody
googlers>
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