john@kk9a.com wrote:
> This seems like a lot of trouble just to remove a rotator and it still
> doesn't stop the mast from spinning.
Drill and tap the sleeve for 3 3/8" or 1/2" set screws. Remove burrs
from set screws so they don't dig into the mast. If necessary weld a
nut over each hole and then thread the mast through the nuts to give the
threads more purchase. You can put matching flats on the mast at that
point so it doesn't take a lot of pressure to hold it.
You can get really fancy by using/modifying the collar that goes above
the sleeve so it can drop down onto the sleeve and lock in place. That
can be done by using a few inches of pipe/mast/DOM that fits over the
collar and sleeve. Put put flats on the outside of the sleeve at the top
and the bottom of the collar. Again use large set screws to hold the new
piece to the collar and sleeve. There are many variations of using the
collar and sleeve locking. to prevent rotation. They sound complicated,
but are quite easy to do.
> How often are we changing rotators?
>
>
Depends on how often it needs it. Reasons such as seal failures, motor
failure, gear failure, direction indicator and whether it's large enough
for the job will most likely determine the maintenance schedule.
Normally every 10 years or so, unless experimenting or the rotator is
under size. Then it could be quite often.
Actually when using thrust bearings that support the weight by clamping
to the mast I like a spline attachment into the rotator, much like the
spline on a drive shaft that allows a bit of vertical movement. I don't
use one, but think it'd be a good idea. You just don't want any play in
it.
73,
Roger (K8RI)
>
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