I've seen some. Different variations. I probably should not have used the word drone... as that word seems to have been associated with multicopters. I just mea

I've seen some. Different variations. I probably should not have used the word drone... as that word seems to have been associated with multicopters. I just mean an autonomous vehicle. I think one of the best designs are those gliders that use the sliding weight to propel themselves by gravity/lift. Best in terms of energy efficiency. Cool video on that too how it works https://youtu.be/WVg47-5Skjs?t=76 https://youtu.be/WVg47-5Skjs?t=76