[TowerTalk] PST61 Rotor Reliability?

[David Gilbert]

Thanks for the reply, Steve, but I'm sorry ... that doesn't make sense.  
Torque is torque, and it's in the same direction no matter which side of 
the mast is applying the torque.

Picture this ... I have a turnstile on the ground with one long pole 
clamped to it.  I get Person A to push one end of the pole clockwise 
(when viewed from above) and Person B to push clockwise on the other end 
of the pole.   Now I add a second pole to the turnstile, but I clamp it 
to the turnstile on the opposite side of the turnstile from the first 
pole.  I add Person C and Person D to push the second pole ... also in a 
clockwise direction.  All four people are pushing clockwise and their 
torque vectors add.

Again, it is important to understand that I get strong SWIRLING wind 
gusts ... literally mini-tornadoes.  If one of them (I'm going to assume 
it is swirling counterclockwise when viewed from above) hits my tower 
head on from the south, and my boom happens to be oriented east-west, 
half of the swirling wind tries to push the eastern half of the boom 
north while the other half of the swirling wind is trying to push the 
western end of the boom south.  Those are additive torques no matter 
which side of the mast the boom is attached to.  And if you think about 
it, the same problem exists no matter which direction I have the 
antennas pointed.

73,
Dave   AB7E



On 12/10/2017 11:36 AM, k7lxc at aol.com wrote:
>
>     >  The problem is that in the springtime when it gets really windy here,
>     the high ridge line to the west and south of me blocks those
>     prevailing
>     winds and turns them into swirling wind gusts that AVERAGE
>     anywhere from
>     50 mph to 80 mph about every three to five minutes ... with peaks
>     sometimes reaching 90 mph on a bad day. When those swirlers hit the
>     tower head on, the forces on each end of the boom don't balance
>     ... they
>     add. The resultant torque on the mast must be tremendous, and in any
>     case it eventually managed to strip the gears in the NE position.
>
>         If the antennas are mounted on the same side of the mast -
>     yes, the additive torque is significant. My advice is to mount the
>     antennas on opposite sides of the mast. That way, much of the
>     torque is cancelled out. Dick Weber pointed this out in a QEX
>     article years ago. That should have positive effects on your
>     rotator as well.
>
>     Cheers,
>
>     Steve    K7LXC
>
>     TOWER TECH
>