It's not just the SpaceX launch that is delayed, though we're still set for final assembly and flight-testing during the closing week of this month. After discussions with Angus, who'll be doing the tuning and flying, we opt to revert to alloy for the upper drone that will be doing the steering ~ so as to improve stiffness at the cost of additional weight.
Meanwhile the lower drone remains almost wholly plastic, as its motors will merely be supplying the heavy lifting at this stage of the game. I sub the feet for skids, a feature of this drone being the fact that it can be used either way up (skids here uppermost). In fact there is an argument for flying it this way up, which we'll do for the test-flights, as it reduces the vertical extent of the vehicle and reduces the static loading of this structure whilst it is at rest on the ground.
Seen as here it has merely to hoist the payload into the air, with motors mounted on those stubs. Otherwise it (and the undercarriage) would need to support the entire weight of the payload and upper drone, whereas otherwise that function is fulfilled by the ground itself.
I've always been interested in the structural aspects beside the aesthetic and will ever err on the practical side. Buckminster Fuller was expelled from Harvard for not towing the party line, and became an alcoholic in his early thirties ~ whereupon he resolved to design innovative structures for the benefit of humanity.
If I've any advice at all for my son, it is not to fear dropping out ~ for we live in a world fashioned by freaks and failures.
