[TowerTalk] Rotor load bearing weight

[Patrick Greenlee]

I think it is the universal answer, "It depends."  In the case of a Kurt 
Andress converted prop pitch motor (a small one) he told me to let all 
the weight (over 250 lbs) rest on the rotor/rotator before tightening 
the clamping bolts/set screws on the thrust bearing(s.) I can see how a 
marginal unit might turn a heavier antenna and mast than it could safely 
support without accelerated wear or catastrophic failure. Surely the 
manufacturer must offer max load capacity ratings. I would not advise 
getting close to any published specs for fear of shortening the life of 
the equipment.

If you choose to let the rotor/rotator carry the load then perhaps you 
would consider mounting the unit above nuts on vertical bolts so that in 
normal use the weight is carried by the rotor/rotator which is supported 
by the nuts on the vertical mounting bolts.  With a little clearance 
below the nuts you could lower the nuts which would transfer the load to 
the bearing and remove the load from the rotor/rotator.  This would free 
the rotor/rotator to be removed and leave the antenna(s) and mast in a 
safely supported manner.  You would want to secure the bolts to handle 
torque or otherwise they might flex sufficiently to cause a failure.  
This is not so complicated to do as it is for me to describe in text. 
While the rotor/rotator is removed you should secure the mast from 
rotating or it might destroy the coax loop that lets the mast and 
antenna(s) rotate.

Caveats:

1. I am not a degreed mechanical engineer.
2. My meds might not be properly titered.
3. The second paragraph above is my conjecture, unsupported by 
experience and previously unreviewed by competent authority.
4. Fitness for any specific use is purely coincidental.
5. Use of anything in the commentary above is solely at the risk of the 
user as it is submitted for its entertainment value, if any and no other 
use is recommended, authorized, or intended.

Patrick        NJ5G


On 4/24/2016 11:30 PM, Chuck Gooden wrote:
>
>
> Should the rotor in a tower, bear the weight of the antennas and 
> mast?   Or should the weight be on a bearing plate, and allow the 
> rotor to be easily removed?
> What are the pros and cons of either approach?
>
> Chuck Gooden N9QBT
>
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