How to calculate the required torque for an azimuth/elevation antenna rotator?

Question

I want to build an antenna rotator for a 1M dish. How do I calculate the required torque for the motor of the elevation axis?

Here's a sketch of the problem:

If the "bottom" of the dish is the pivot point, what would be the required torque to rotate the dish around this pivot point? Obviously the motor will have a series of reductions to reach the required torque and speed. The last stage a worm gear with a turn ratio enough to prevent rotation from the antenna weight when no power is being applied.

kamran · Answer

we just do it for gravity and assume 90% efficiency for the gear, or if they have a datasheet look that up.

Regardless of the dish being perforated in certain angles it could act as a wing and create flutter, lift,  destructive vibration. So we need to use a light truss to stiffen the dish.

Let's call the dish mass m and its depth H, and assume by just eyeballing the parabola's CG axis is at H*0.45. and say we want the torque $  tau  $ to deflect the dish from horizontal to 90 degrees up vertical.

$  tau_{max }= m *0.45H/9*(1/0.9)=0.055mH$

How to calculate the required torque for an azimuth/elevation antenna rotator?

One Answer

Add your own answers!

Ask a Question