[TowerTalk] Analysis of mast slippage in rotor

[Roger (K8RI) on TT]

On 10/6/2013 1:14 PM, John Becker wrote:
> Thanks to all who responded on this issue.
>
> It appears that there is no perfect solution. The weak link for the 
> HAM-III and related rotors is the limited strength of a 1/4-20 U-bolt.
>

As a thought; How about drilling a matching indentation into the mast?It 
wouldn't have to be deep, just enough for the end of the bolt fit and 
just snug, not tight enough to counteract the designed function of the 
plate.  IOW, It'd give a good, non slip connection, of course it'd have 
to be in the right location and if the antenna ever slipped on the mast 
you'd probably have to make the correction there instead of at the 
rotator.  It's much like pinning the mast but not quite as drastic and 
has most of the same drawbacks. The indentation would only be deep 
enough to reach the diameter of the bit which should be the sane 
diameter as the bolt.  This would give a conical depression to fit the 
end of the bolt and no deeper.  It still should be quite effective even 
if it were shallower.


73

Roger (K8RI)


>
>
> One other thought comes to mind. The original design includes a bolt 
> threaded through the center of the backing plate which is intended to 
> be screwed down against the mast. I'm thinking that this actually may 
> be counterproductive, because any force applied at this point would 
> reduce the pressure between the mast and backing plate along the two 
> 4.5" lines where they are in contact. Therefore, I'm considering the 
> removal of this bolt. Your thoughts?
>
> 73,
>
> John, K9MM
>
>
>
>
>
>
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