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@gmail.com>
To: <towertalk@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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