For this project I started with a micro RC car that had lost its tires and become unusable as a car, but the motors and RC circuit still functioned. The first step was to extract the electronics from the chasis. Some pieces were glued in place so care was taken to keep the tiny components intact. Once free from the chassis it was necessary to change the motor leads solder connections to the board, in order to get the motors to work together forward and reverse and opposite each other to turn left & right. The balloon was an impulse buy at the supermarket. I had learned from a previous attempt that the balloon needs to be at least 36" diameter. It doesn't help that I'm at altitude.
The propellers were stolen from my sons batmobile toy and hot glued to the gear on the motors. The motors were placed as far apart from each other as I could, using the original wires, and glued to a wooden skewer. Finally the skewer was taped to the bottom of the balloon with the propellers pointed slightly down, to provide some control of lift. After dialling in the required ballast, a spring clip and a couple pennies, it was ready for the maiden flight.
As a midnight maker I am inspired by the open source community to contribute and share some of the projects I have attempted.