Satellite Tracking Head Unit

This is the fun part for the mechanically inclined and a no-brainer for the rest of us...!

Just in case you haven't already figured out, the AZ/EL head unit consists of an Azimuth Rotator and a Elevation Rotator. The Azimuth Rotator is capable of rotating anything mounted on it from 0 to 360 degrees in the horizontal (Azimuth) plane. The Elevation Rotator is capable of rotating anything mounted on it, from 0 to 180 degrees in the vertical (Elevation) plane. Now, mounting the Elevation Rotator on top of the Azimuth Rotator gives us the ability to point anything mounted on top of this assembly to any point in the sky from horizon to horizon. See the following concept diagram for illustration.

Now, lets look at constructing a Azimuth Rotator. The Azimuth Rotator consists of an rigid plastic frame like an open box with holes for mounting to a fixed support like a sturdy mast or a sturdy camera tripod. An RC Servo Motor is mounted inside this open frame, as shown in the following illustration.

It is important to note the vertical zero moment axis, because anything mounted symmetrically along this axis will present zero sideways stress on the RC motor and enable smooth rotation along this axis.

Notice how the servo motor are attached to each housing with minimal mounting parts.

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While using normal RC servos, I found a 3inch x 3inch x 3 inch cube shape to be adequate for the lower Azimuth rotator (the black box in the picture). However I needed a longer 6 inch piece for the Elevation rotator, the white u-shaped plastic in the picture.

The reason for the longer piece is evident when you see that I had to use pipe sections to gain sufficient rigidity with the antennas attached. Feel free to suggest alternate ways of achieving the same results.

Questions?

I have not provided extensive step-by-step instructions or dimensions to duplicate the project, because I hope that you can figure out the details specific to your decisions within your project. However if you do have any questions about the items on this page, I try my best to answer them by adding more content on this page. I can be reached at k6vug@sbcglobal.net