N.B. THE FOUR ARMS SHOULD HAVE BEEN 37.125" INSTEAD OF 38.125", SHIT HAPPENS.
Well with that out of the way, let's move on to construction of the 'drone itself and we start by taking those arms and applying a squeeze of silicone around the inside edges of all eight ends before tapping in the threaded M6 inserts... from which I have to say the average fabricator will draw a practically sexual satisfaction (or at least until those rivets are driven home).
I've opted for 4 x 12mm pop-rivets as a good all-rounder, and a 3.9mm drill-bit offers the tightest fit, although I've gone for a 4mm bit as it is available on any desert island. Apply those rivets to opposite sides as a belt-and-braces fix, and we'll see later that these opposing pairs need to be oriented methodically during assembly.
Airworthiness inspectors might question whether this meets required tensional specs and should this be a sticking point. Offer to hang them from the rafters with the same method and if the joints prove to be up to scratch, then you're clearly the winner...
