Okay so far as it goes but as ever am not entirely satisfied and figure it can be made more practical again... kind of feeling our way in the dark here. "How goes it?" types of review like this at each stage of the game are invaluable when it comes to the lessons to be learned. The study of static and dynamic loads is essential, it having accounted for the loss of a Space Shuttle, for instance, and what I don't like here is the load the lower drone is subject to by the weight of all that above.
You can see it in the flexing of those perimeter spars, albeit constructed in plastic as they are. This temporarily depressed me, and especially so after a week's work on the project, but as ever there will be a workaround. Taking comfort from the positives is essential in prototyping, and we can list these as being (a) it goes together quickly and easily (b) a pair of quads separated vertically appears to be credible and (c) I like the 'flight-deck' a lot.
The latter splits fore-and-aft to form a natural back-rest and safety-restraint, as well as a flight-control console. The foremost half is slid into position using U-section rails and locking-pins, whereupon it acts as a brace that reinforces the 'transporter' tower. The tower itself is self-contained, and therefore able to be detached from each drone. As yet these modules are loosely stacked, though aligned in place by use of four nubs on the surface of each drone which engage with holes in the floor and the roof of the tower itself.