[TowerTalk] Rotator Choice for Larger Yagi

[jimlux]

On 5/4/16 5:29 PM, Roger (K8RI) on TT wrote:
> My thanks to whoever posted the note on K-Factor from Eham.net!
>
> All you need to know for the rotator is how much torque it will handle,
> Calculate the K factor for the antenna,  The rotator torque needs to be
> greater than the calculated K factor for the antenna(s).
>


Not really


K factor comes out in a force * distance (foot pounds) but it's not a 
torque because acceleration doesn't factor into it.

Inertia would be mass * distance ^2
Acceleration would be a angle/time^2

T = alpha * I = mass * distance^2/time^2

Torque is force * distance = (mass * distance/time^2) * distance

You could assume some nominal acceleration (1/sec^2) I suppose and then 
hope that the scale factors come out right.  Maybe for feet and pounds 
it does?