After trying the cheap plastic unit, I decided to build a more sturdy pan-tilt mount for my receiving loop antenna.
There were three problems with using the cheap Chinese pan-tilt structure. First, it was designed to hold a really small FPV camera, not an antenna. Second, it put all of the weight on a tiny servo motor output spline and shaft used for rotation. Third, it wobbled.
My home-made sturdy pan-tilt structure addresses these problems. The biggest improvement is a plastic bearing to distribute the weight over a much larger area. This is shown at the bottom of the right-hand picture above. The inner part of the bearing friction-fits into the PVC pipe used as a base, and also holds the servo horn. The middle section holds the motor and has a ring that fits over and around the base.
3D Printing the sturdy pan-tilt mount
Designing this in CAD required careful work, mostly because of the fine dimensions and measurements needed. We are talking tenths of millimeters to get the servo motors nicely fitting in the right places. As for the overall design, I was able to find a similar effort on Thingiverse which I used as a reference. I was also very useful to have a good data sheet for the servo motors, which provided detailed dimensions.
Five 3D printed plastic pieces were required – base, middle, two sides and top. They were printed with PETG using 20% infill.
As for hardware, I am getting a lot of use from a box of M2, 12 millimeter long screws. These are used with captive nuts to hold the sides onto the middle piece. They are also used to mount the servo motors, and will also be applied to attach the antenna frame to the top piece.
Once again, having a 3D printer enables construction of custom parts easily, quickly and cheaply.