[TowerTalk] Keeping antennas straight

[Jim Lux]

On 4/19/14, 1:29 PM, Richard (Rick) Karlquist wrote:

>
> This class of problem involves many uncontrolled variables
> such as friction, and how closely a clamp such
> as a Slip Knott fits the mast, how much the mast deforms
>

> know what slipped.  Also, be careful what you wish for.
> If you have no slip as a mechanical safety valve, your rotator
> may break.
>

In the long run, something like a camera pointed up at the antenna and 
some software to recognize the instantaneous position of the antenna 
which then controls the rotator might be the way to go.  Then you don't 
care if it slips,and in fact, you can put what is effectively a slip 
clutch on it to limit the torque.

This is what they do with some motorized gates: the drive from motor to 
gate is through a sort of band clamp arrangement. If something jams the 
gate, or a car pushes through, the clamp just slips.  The feedback to 
the motor controller is driven off the actual gate position, not the 
actuator.