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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