Motor + Gearbox: Because of budget considerations, we wanted a cost-effective motor setup that provided enough holding torque (including a FoS margin) for the system. The top structure was our main concern, as without a counterweight, the max torque is quite high when all the antennas are pointed at the horizon. (This meant that the holding torque was the greatest at this location). We settled on a motor connected to a 50:1 gearbox. For the future, make sure that the motor can go directly into the gearbox, as this would eliminate another failure node and provide easier assembling. The motor selection must be approved by the Avionics team (they will have criteria and limitations based on allowed voltage/amp). For the bottom structure, a smaller motor + gearbox worked quite well.
Turntable: Allows for 360 degree rotation quite easily. We used two different turntables, and found that the connection point between the motor to the turntable proved to be difficult to assemble precisely.
Elevation Rod: A long rod allows us to put the antennas in line with each other while also maintaining antenna distancing rules set. The antennas are attached to the rod via u-bolts or other clamping devices that came with the components. The rod itself was epoxied to a metal piece which is connected to the elevation motor, allowing for up and down movement.
Slanted Wooden Legs: We took inspiration from tripods and tables and used four slanted wooden legs to stabilize the structure. we added adjustable table legs at the bottom of each leg, but they didn't come into use much (during the actual test launch the ground was also muddy). The choice to use wood came from budget considerations.