Eureka!

I have to finalise the design on this day of all days, fifty years hence from the lunar landing.

I've fought shy of this layout for some time because I could see no easy way of negating the torsion to which it would be prone along the length of those tubes.

Since the outset however (or not long thereafter) it occurred to me that quadcopters could be fixed both top and bottom, not least because the latter provides means of supporting the vehicle at rest.

Experimenting in the lounge today with lengths of dowelling I realise that by using a support around the mid-riff (and I've built many in connection with the 'wearable' drone) the rigidity of the arrangement is improved sufficient for it to be the basis of a prototype.

Let me recapitulate the course of the design effort to date, with the pros and cons:

(a) A form of flying phone-booth ~ too heavy and too complex at this stage.

(b) A hollow drone worn at the mid-riff ~ essentially been done elsewhere.

(c) A ground-level drone to sit or stand on ~ neither new nor original.

At times in the past I dreamt of helicopters with a rotor both below and above the cabin, as it answered two of the challenges associated with conventional rotor-craft viz. retreating blade and a tail-rotor to counteract torque.

At the time the idea was too complex given the state of the art, but with distributed rotor-arrays used by eVTOL technology it is feasible to build an airframe not dissimilar to the one above, which features a set of propellers overhead as well as underfoot.

And I intend to build it.

Next I have to get over to the electrical engineer's farm where ~ beside everything including the kitchen sink ~ there's an ample supply of full-size mannequins.

Shall build the frame around a junior mannequin at the outset, not least because these are the only type with moveable arms that I can fix around a pair of joy-sticks, as if for flight.

Space Frame

Complete the pair of frames to be used at head and foot of a vertical airframe designed to fly a pilot stood upright.

Been fifty years since the launch of Apollo 11 ~ which I recall watching on TV ~ and occurs to me how tasks do well to be split into component parts.

The space-frame installed between drones above and below an operator can similarly be treated as a module able to be built separately.

The quadcopters here have a base just twelve inches square, on cantilevers thirty inches long.

I've stuck with alloy and rivets because if it works on a 747 then it has to work here too.

For the Record

Actually, see no need for suspending the blog during the course of construction because (a) seems churlish and (b) it's my diary and I'll cry if I want too...

In order to squash a 'flying phone-box' into the allowable dimensions ~ complete with quadcopter top and bottom ~ I've to reduce their foot-print to a minimum.

This involves dismantling the previous build and recycling the parts, which initially involves foreshortening the cantilevers that support the motors and propellers.

With nine inches to come off each, my preference over the jig-saw is to take them to a local engineering workshop for a straighter cut... achieved as above with a band-saw instead.

The veteran (who has broken off from the current task to attend) refuses to accept any cash.

I insist on a tenner however, suggesting he use it for lunch?

Says he'll buy a pint on the way home from work.

My kind of engineer.

Under Construction

Been ham-strung from the outset by the outline dimensions required to meet the GoFly challenge, which inadvertently penalises airframes that extend vertically whilst remaining inside the admissible foot-print.

Nonetheless if this concept has any value at all, it lies in the recognition that most people do their commuting (when they're not sat in a traffic-jam) while standing up.

I'm not going to compromise on this despite my myriad attempts at a work-around, but I do envisage a proof-of-concept at full scale that retains a drone at top and bottom whilst still meeting the criterion of being 102 inches from any one point on the vehicle to any other.

Until that prototype is airborne, though, I won't be updating either the web-page or the blog.

For a single flight (as Boeing 707's test-pilot commented) is worth a thousand speculations.

Garage Drone #6

... and finally the two halves are bonded together to produce the octocopter. The parts here are joined with adhesive and will be secured with tie-bolts that pass through both halves.

Garage Drone #5

... before the centre-space of each module is bulked out with PVC or PU foam block...

Garage Drone #4

For each of the modules, a dozen pop-rivets are used to secure...