A 3D printed balloon mold (left), showing air intake holes on the top and bottom, and thrust output holes on all four sides. The mould would be dissolved once multiple layers of latex and coagulant had been applied and dried. The print took upwards of 10 hour, and so wire cut styrofoam spheres were tried instead, but these had too many sharp edges. The resulting balloon (right) was filled with helium from a pressure tank. This hole turned out to be a point of failure for many prototypes. An impeller fan would move the drone laterally, and a string with a spool would keep the drone from flying away, while allowing for a reasonably large operating range.

3D printed balloon mold

Latex balloon prototype filled with helium