Much of what we see here has been influenced by my carting sub-scale personal air vehicles the length and breadth of the country, and what that means for practicality.
Among my first concerns was the exposure of the propeller blades, not so much as regards the limbs they might separate as to how they might be damaged or blood-stained.
Bear in mind that aircraft ~ and increasingly personal air vehicles ~ make no effort whatsoever to shield bystanders in this regard, which is why any number of people have died walking into propeller and rotor blades.
I think we can improve on that in the fulness of time, and principally I feel by using an array of sensors (as cars are festooned with nowadays) to shut motors down when anything with a pulse appears within the circle of operation.
Failing that, or as well as, it is about perspicuity and propellers once spinning have never been awfully good at this. Accordingly I shall set the power-units on a bar in order to 'outboard' them, viz. make them removable on demand in just a moment.
This has any number of benefits, not least the fact that the extent of the assembly (which I shall call the 'sound bar' or 'power bank' as it's my party) is obvious to a bystander. Besides that (a) it allows for rapid replacement or practical repairs in the field (b) it allows for removal for transport and storage and (c) it allows the craft to be stood on end for maintenance or storage without damaging its 'Achilles heels'.
It hurts that the axes of the motors are not aligned with the booms, but does mean the rig can be dropped into place on half-cent brackets. These being pusher-props too, under power the motors are trying to stay fixed rather than tear themselves from their mounts as would tractors.
Accordingly, as was the case of any number of the scale personal air vehicles which we flew, the motors will be mounted on the spar by just two bolts instead of four.
N.B. Blades swing outboard and downwards, CCW and CW viewed from rear. Power to the left motor applies differential thrust for a turn to the right, and shifts weight onto the right ski by torque reaction to supplement the effect.
