Matt T Powell wrote:
> Hi,
> Has anyone experienced rotator / plate mounting bolts loosening up,
> to the point of falling out ? I have had 2 cases of this happening,
> which were discovered this weekend.
>
> Both rotators were T2X's. One turns a 2 element 40 meter yagi and
> the other turns a stack of monobanders on 10-15-20 meters. Each rotator
> was installed this spring. All mounting bolts had 1 flat and 1 "split "
> lock washer on them. All were installed with a small amount of grease on
> the threads.
>
> Maybe a "star" washer would correct the problem ? Thoughts or
> comments.
>
> 73 Thanks Matt W3UUM
>
Hi Matt,
All hardware in an antenna system is subject to loosening due to
vibration caused by the wind.
Get rid of the split and star washers and use a thread locking compound
like Loctite.
For stainless bolts in a cast aluminum rotor case use Loctite 242, blue
compound. It will lock the fastener, and come apart without damaging the
weaker cast aluminum threads.
You need to completely clean the mating threads to get rid of the grease
first. Lacquer thinner works well for this. Then make sure the solvent
has completely evaporated before assembling with the Loctite.
73, Kurt
--
YagiStress - The Ultimate Software for Yagi Mechanical Design
Visit http://www.freeyellow.com/members3/yagistress
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|