None of the hardware construction looks all that expensive. (I've watched the video a few times, tried to catch a few details.) They're pretty high-speed motors

None of the hardware construction looks all that expensive. (I've watched the video a few times, tried to catch a few details.) They're pretty high-speed motors, obviously, and otherwise lightweight construction. The real trick is how they're getting them to calculate vectors. They're certainly not just remote controlled -- not unless they had an awful lot of takes of that 3" clearance shot -- so that raises the question, are they precalculating the vectors, or are they using some really advanced method to calculate them on-the-fly (so to speak)? If they're precalculating, then the impressive thing here is the method they've developed to get these things to do tricks with rotors. If they're doing on-the-fly calculation, then I really want to know what kind of sensor they're using. I don't know of anything available on the hobbyist market with that kind of resolution and speed. EDIT: Well, this is embarrassing. It spells out the answers to my questions right in the linked article. :-( Hooray for not paying attention.