to make something float

outside needs to be a light airy ball, inside is a straightly spinning motor inside the ball almost elastic, the force of the motor ( That NEEDS to be light almost like a rc car) will bring the ball up, if only there was a way to bring the downward speed of the “rc car” so it could float. Making it lighter would not help because then it wouldn’t bring it up. Smaller would increase the density, and larger wouldnt give it enough space to turn. all we need is a way to suppress it the downword turn and we could make it float