[TowerTalk] G-1000DXA failure with lower mast clamp

[Barry N1EU]

Has anybody used Nord-Lock vibration proof lock washers?

http://www.youtube.com/watch?v=mgwmuZuJ02I

Barry N1EU

On Tue, Dec 27, 2011 at 3:50 PM, Barry N1EU <n1eu.barry at gmail.com> wrote:
> Thanks for responding Chuck.  I'm on rented property, so I need to use
> the AB577 and a lower mast adapter type rotor installation.
>
> Isn't there any way to prevent the bolts from working loose like they
> did?  Better type of lock washer or ????
>
> Barry N1EU
>
> On Tue, Dec 27, 2011 at 2:29 PM, Chuck <w5pr at swbell.net> wrote:
>> Hi Barry,
>>
>> Glad you didn't have damage to the beam.  I don't know much about the 3el
>> Steppir, but that seems like a lot of antenna for a mast mounted rotor. The
>> antenna wobbles back and forth, loosening the bolts. A stick of Rohn 25 with
>> a rotor shelf might serve you better.  The weakest point will fail.  If the
>> bolts drop out when the rotor is on a shelf, it just twists.  As for this
>> rotor, I think I would be ok with using it.  Three bolts should hold it and
>> it looks like you could still catch a few threads on the fourth.
>>
>> Good luck,
>>
>> Chuck W5PR
>>
>>
>> ----- Original Message -----
>> From: "Barry N1EU" <n1eu.barry at gmail.com>
>> To: <towertalk at contesting.com>
>> Sent: Tuesday, December 27, 2011 8:16 AM
>> Subject: [TowerTalk] G-1000DXA failure with lower mast clamp
>>
>>
>>> My G-1000DXA rotor came completely unhinged from its GC-038 lower mast
>>> clamp and left my 3-el Steppir and attached rotor dangling from the
>>> attached cables.  It appears that the attachment bolts on the bottom
>>> of the rotor came loose and fell out.  Please see photo at
>>> http://n1eu.com/g1000.jpg
>>>
>>> The cast aluminum fractured at one of the four threaded holes on the
>>> rotor bottom.  At first I thought this might be the cause of failure
>>> but on further thought, I would guess that the other 3 bolts came
>>> loose and fell away and this fourth bolt was the last to stay attached
>>> and this caused the aluminum fracture.  Any comments on whether this
>>> seems correct?
>>>
>>> I'd also appreciate comments on why this happened in the first place
>>> and how to prevent a repeat.  The rotor was assembled to factory
>>> instructions with lock washers.  Instead of using anti-seize on those
>>> four bolts, perhaps what is really needed is loctite?
>>>
>>> Does the motor casing need replacement and if so, is this a fairly
>>> easy job to do myself?  There's still about half the threads on the
>>> one hole that suffered the fracture.
>>>
>>> Thanks & Happy Holidays,
>>> Barry N1EU
>>> _______________________________________________
>>>
>>>
>>>
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