Velodrone

The Airbus A320 this last week became the best-selling jet-airliner ever, though it nearly didn't happen at all. Though the first jet airliner was developed in the UK in the 1950s, manufacturers in the USA dominated the market in the 1960s by taking advantage of the fragmentation of the market in Europe. Only when the British, French, Germans, Dutch and Spanish combined their efforts in the A300 (the first wide-body twin) did it literally take off.

From the outset then, the Airbus story has been one of moving parts around to tally with the expertise located elsewhere. In a very modest way we've replicated that today: the top-end of the flying phone-box being transported on the roof-rack of a Suzuki Jimny 200 miles south to one of the team-members south of Bristol. Here ~ all being well ~ the avionics controlling the motors are to be wired up so that they can be bench-tested with the propellers in place.

We're also offered the expertise of drone-builders Vulcan (http://vulcanuav.com) for fine-tuning the rig for the purposes of control and stability.

So things are finally looking up... literally.

Octobus

Proud of this as it encapsulates the best of my thinking over recent months. It's ready to be transferred to another team-member who will attempt to get it flying independently with a smaller of batteries.

Whilst that's happening I shall continue construction of a 'phone-booth' of 50cm square and 150 tall, large enough to include a seated passenger whose lower legs will nonetheless dangle outside.

Beneath the seat a larger set of batteries will transfer the current up the four columns to the motors that you see above, via an avionics bay contained within a 'dome' that surmounts the centre-section.

The net result will look much like the classic K8 telephone-kiosk (as seen at http://www.the-telephone-box.co.uk/kiosks/k8/) but equipped with eight propellers and able to 'teleport' people who might otherwise have telephoned instead.

Space-Frame

Phone-booth's taking shape at last. I have ordered too few connectors for each of the corners but can crack on with fitting the base meantimes.

The airframe is constructed from a pair of five-metre lengths of inch-by-inch-by-sixteenth alloy divided into four 1375mm stanchions, eight 450mm cross-bars and two 450mm seat-supports that serve at the same time to brace the sides.

I recycle old alloy plate for the base because (a) I don't like waste and (b) it saves me a trip to the stockholder.

Prototypes are meant to be rough and ready in my book. Just seen the Ford v. Ferrari movie for inspiration, with Carroll Shelby given just ninety days to put the GT40 together.

The '40' referred to the maximum height allowable in inches, which is unusual with France having long organised European motor-racing and them normally working in metric.

There has always been a form of tug-of-war between France and Great Britain when it comes to laying down the regulations for these things, however.

Vital Parts

They used to say in the USA, and perhaps they still do, that an idea's worth a dollar, a product's worth ten and a factory's worth a hundred.

One reason for this is that prototype construction proceeds in fits and starts, not least due the availability or otherwise of its 'nuts and bolts'.

I want to strap the two drones that together form the 'motor-head' of the prototype as non-invasively as possible. Every hole in an airframe ~ and not least the portholes, as proved by the De Havilland Comet ~ is a potential focus for failure.

Accordingly I consider those rubber bonnet-straps you see on rally-cars, but settle instead for sprung fasteners of the sort you see above (which is stressed to 90 kilos, incidentally).

Britain's richest native industrialist, James Dyson, has lamented the dearth of factories left in the UK producing these sort of nuts and bolts. Basically they've all gone west, and when in Shanghai I used to buy them by the sackful, they being 'cheap as chips'.

Good to see therefore that these are marked up 'Redditch UK' and therefore sourced from the Midlands, that great heartland of manufacture in this country.

It's not just me, either. Production of the Boeing Dreamliner has been held up at times due to a shortage of rivets...

Motorhead

What I should have done yesterday, I suppose, I've done today. Often however unintended breaks prove beneficial, providing space for new ideas to surface unawares and it is during one such that I finalise my 'best shot' as regards what should be fixed to the top of the flying phone-booth.

And this is it, pitched on the floor in order to check the clearance between motors, propellers and wiring. This stands at an inch and a quarter between opposing blades, which is more than sufficient by my reckoning.

I once shared an airfield with the UK agent for Enstrom helicopters, whose heart-stopping aerobatics in same I also witnessed. He said that to see how far they could ~ literally ~ push the main-rotor in flight without it striking the tail-rotor, they would strap a balsa strip to the tail to see how much it would chop off... it being altogether less critical to flight performance.

Question now is do we try to get this motor-head flying independently before such time as fitting it with the passenger compartment and full-size battery-packs? At least one of the GoFly 'webinistas' advised against flight-testing modules independently, if only to avoid the potential waste of time.

Jymn-astics

Said it before but a great deal of the time and effort involved in pursuing projects is the sheer legwork involved.

We're on the final build of the prototype octocopter, which restores the notion of a flying phone-booth (albeit on a smaller scale to support a seated rather than a standing passenger) and to that end there are two more quadcopter frames to build beside the chassis.

For any number of reasons to I've reverted to a 50-cm square footprint, and am out of foam for the core for each of the drones, so that a trip to the DIY store for a sheet of insulation is required.

I've recently found that altogether preferable to straps is using tape to affix various loads to the roof-rack of the Jimny, although it does require limiting the speed to below 30 m.p.h. on the motorway.

This being the North of England I am treated with indulgence by my fellow motorists, whereas I'd probably have been lynched on the London orbital.

Together in Electric Dreams

Much development hinges on driving around either purchasing parts or moving them from A to B.

Going forward I've decided to split the prototype development into three in a form of work-share in which Phil will configure the lower quadcopter, Martin the upper whilst I build the intervening chassis.

This entailed a 400-mile round-trip to Somerset yesterday to drop off one of said quads...