If I ever get to the point where I can make a couple of types of items I believe I can create a vacuum ball drone that will have enough lift to weight ratio to be effective.
One cubic meter of air weighs ~1.2kg = 2.6 pounds. If I can make a 1-meter diameter vacuum ball that weighs less than 0.6 pounds, it would have a lift of 2 pounds.
I believe that by using mylar and a support structure of a icosikaitetragon (24-gon) or 24 sided polygon, using ultra lightweight Bosch Captive Columns, I can achieve this. I just need the means to work on it.
Those that have read Mission To Sector ZZ-1219 may recognize the reference to the Bosch Captive Columns.
The icosikaitetragon would be a structure of three axis beams, the outer points connected to form an octagon of 8 triangles. An axis beam from the center junction of the first three beams would go to the center of each of the 8 triangles, with beams connecting them, forming three triangles each, for a total of 24 sides.
The mylar would then be attached, with a fitting at one point with a valve. A vacuum pump would be attached and the ball evacuated of air. If I use the right materials, in the right way, and the vacuum ball weighs ~0.6 pounds, the ball should lift up to two pounds of payload.
Just my opinion.