[TowerTalk] Recommendation for mast on bottom mount rotator

[K8RI on TowerTalk]

>
>>
>> <snip>
>> >K8RI made a good point.. I assumed that you'd have another thrust
>> >bearing at the bottom to hold the weight of the torque tube. If not,
>> >then the entire weight of the tube will also be on your top
>> thrust bearing.
>>
>
> I thought the purpose of a thrust bearing was to stabilize the mast
> horizontally and not to take the weight of the mast/antenna array off the
> rotator.  The set screws are adjusted to remove 'wobble' or mast slop and
> not to take on the mast/array weight.

Many commercial bearings just don't work that way. The ROHN TB-3 and 4 as 
well as the Yaesu would be difficult to install in the normal manner without 
them supporting weight. Both have an upper and lower race for the bearings 
although they do well for side loads.  However if the centeringbolts are 
locked while they are just touching the mast, but not applying pressure they 
should pretty much provide only centering.   The Yaesu bearings I've looked 
at appeard to be much lighter duty than the TB 3 & 4, but they sure had a 
much nicer finish and much smoother feel.

Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com (Use return address from home page)

>
> Or is that completely wrong?
>
> 73
> Dale, kg5u
>
>
>
>
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