Steve,
Your problem is not a Cushcraft problem! It is an everyday hardware
application problem.
Whenever, we connect two pieces of material together, we need to put " some
kinda goo" into the connection.
This is the subject of previous posts on this reflector. Please have a look
at the reflector archives.
There are two types of connection and two types of "Goo"!
The first type is the electrical connection, the second type is the
mechanical one.
Each type has similar physical composition requirements to suit the
connection, but different material requirements to make the connection
reliable.
I would guess that your initial installation did not apply any anti-seize
compound to the threads of the u-bolt/nut interface. When you initially
tightened them, you probably heard squeaking noises as the threads gaulled
and locked up. You figured that they were tight enough and quit. When you
recently tried to loosen them, the gaulled materials simply twisted the
u-bolt shafts off. This is not hard to do with 1/4" Dia. fasteners and
commomly available hand tools.
Don't blame your antenna manufacturer, because none of them tell us how to
prevent this. Because, Ham's are predisposed to thinking only in the
electrical realm, they freely sell antennas with the electrical "Goo" to
make good electrical connections, but seldom address the mechanical
problems, because we are predisposed to ignore them! I.E. You could have
purchased another antenna from a different manufacturer and had the same
problem.
To alleviate your frustration about this issue, get new u-bolts from the
antenna manufacturer, go to your local hardware store and buy Nylock nuts.
Go to the local automotive store and get some Permatex(Tm) anti-seize
compound and apply it to the threads of your u-bolt.
Tighten the nuts appropriately, without the dreaded squeaking noises. Then
sleep well, because you know you will be able to get it apart without
drama, and drop a line to your antenna manufacturer about how pissed off
you are that they didn't tell you about the potential problem.
Many years later, when we are trying to educate our grandchildren about the
nuances of antenna assembly, the manufacturers will have addressed this
issue, and provided the necessary "mechanical goo" and manual instructions
to allow us to watch the grandchildren struggle with the "which piece goes
where" problem, and have piece of mind, knowing that we can get off of the
lawn chair and undo their mistakes, without missing a single instant replay
on the game of the week!
73, Kurt
YagiStress - The Ultimate Mechanical Design Software for Yagi's
Visit - http://freeyellow.com/members3/yagistress
----------
> From: W9SN <nw9g@netusa1.net>
> To: towertalk@contesting.com
> Subject: [TowerTalk] Cushcraft U-bolts
To: <towertalk@contesting.com>
> Date: Wednesday, July 01, 1998 9:23 PM
>
>
> Just came down from removing my 2 meter 10 element cushcraft yagi.
> The U-bolts broke backing off the nuts. It sure made life at 100
> ft alot tougher than expected. This yagi was bought new less than
> a year ago. The bolts still looks brand new except for being broken.
> Anyone know why this happened so quickly? Bad materials,
> Operator error? Just don't want this to happen to me again on a
> much bigger antenna next time.
> --
>
>
> ------------------------------------------
> Steve Narducci
> Amateur Radio Station - W9SN
> All Ten Tec Equiptment
> Toys for "Real" CW Men
> ------------------------------------------
>
> --
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