[Towertalk] FOK (Rohn Foldover Tower)

[Wendell Wyly W5FL]

I have a Rohn 45 Foldover also and would not be uncomfortable about simply
copying the existing design (if you can get someone to galvanize the
finished pieces properly).  To go to 70 feet with a much larger tower and
load certainly requires a complete mechanical design of an extremely complex
mechanism.  I was very sorry to see that Rohn has discontinued one of the
greatest products available.  The problem with many amateur products, is
that they last a long time and corporations have taken a very short term
profit posture.

Maybe someone will copy the Rohn 45 Foldover design and make it available
for sale.

K5DUT is the only one that I am aware of that used a 70 foot Rohn 55 tower,
set up as self supporting with a Triangular elevator quite similar to the
Hazer with the guys on the Elevator.  It is a sight to behold.  Don is still
active and using this same setup after many problems with crank up monsters.

I don't think you will find anyone that has tried what you have suggested.
The hinge moments are easy to calculate, but are extremely high.  There is a
very good reason why Rohn never went any higher than 66 feet with their
Foldover Tower series.

-----Original Message-----
From: towertalk-admin@contesting.com
[mailto:towertalk-admin@contesting.com]On Behalf Of A9xw@cs.com
Sent: Monday, April 01, 2002 11:03 AM
To: towertalk@contesting.com
Subject: [Towertalk] FOK


Fold over kit is no longer available for Rohn towers. I have been
contimplating making my own. I have a 45G tiltover Rohn FOK, and want to
tilt
over a 70' 55G tower that will hold an IIX 18' mast,  Big Yeasu rotor and
new
(still in the boxes) Mosley 40-10 meter  monster and a 6 element KLM 6 meter
beam.  I bought two section of 25 G thinking to use that as the cantilever
arm since Rohn no longer makes the cantilever kit and no parts are avilable
either.  i would attach the 25 to the 55 using 2" steel C channel and good U
bolts, leg to leg on all three legs at the end, middle and joint area. Then
use more C channel to make the hinges using the bolt holes in the 55 and
maybe add another a few inches lower, and some 1" or so grade 8/9 bolts as
the actual hinges for the mating lower (support) section.  Finally, run some
C channel as splints over the 25g joints so there is additional strength
there.  At the cable end of the 25 g cantilever arm, tie all three legs
together with C channel and use the new cross braces as the attachment point
for the winch.   Anyone else ever try this for a home made tilt over, or
have
a better idea?  no I cannot trash the new 70' 55G and get a heights or other
aluminum tilt over tower for $12 grand.

Henry AA9XW
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