Friday, October 23, 2020

Don't Bend and Break?


Probably not many people out there trying to design a helicopter that'll fit through double doors, but that's the benefit of operational experience... you learn what works in practise beside theory.

I adjust the lateral stabilisers to slide through the skids, so that they remain removable but are now centred directly on the propeller axes.

Trial and error is expensive however, in terms of both time and money.

These are eight millimetre carbon-fibre tubes, but they don't quite cut the mustard even though I've inserted threaded steel rods inside of each.

I shall likely revert to the tied-and trusted half-inch glass-fibre tubes of the sort accompanying us to California back in February.

As checked-in luggage these survived flight connections at Dublin and New York, and continued their travels around the domestic US network (having been missed in the dark) before appearing as lost baggage at NASA Ames some days later... and wholly unmarked.

Lesson learned ~ stick with what you know.

Wednesday, October 21, 2020

Rotor Talk


As things stand, aside from Joby (six) the best-funded eVTOL projects err on the side of extra when it comes to rotors, with eHang, Volocopter and Lilium sporting sixteen, eighteen and as many as thirty-two.

And you can probably get away with as few as six for human carriage if you are only dependent on these for vertical manoeuvre either side of extended flights as fixed-wing aircraft, as Joby and Lilium's prototypes are ~ the bulk of the world's fixed-wing aircraft having just two engines.

When it comes to pure multi-copters however it would appear that more is better, though I think personally that if eight is enough, then a dozen (as seen here) would be more than enough.

The above would be configured as an independent quadcopter surmounted by an independent octocopter, with the former tasked purely with lift whilst all is well but with the capability to steer the aircraft should this prove beyond that of the octocopter for any reason.

It therefore offers comprehensive redundancy beside modularity, in that each of the drones is interchangeable along with the size and scope of the payload compartment.

(It is also a significant variation in view of the fact that EASA in their ~ lack of ~ wisdom dictate that even in the event of a forced landing, eVTOLs should retain directional capability: I say that is fine so long as they insist that airliners with a double engine failure and similar rate of descent should be able to maintain a forward speed of zero in much the same way.)

I register the idea in patent and design form if only by way of technical disclosure, because once the octo is flying regularly someone sooner or later is going to suggest twelve propellers instead.

It was Edison who said that you could guarantee that having developed any particular product that there would be any number of people emerging from out of the woodwork to say they had thought of it first.

My thanks to cousin Mat for this marvellous render in SketchUp... turns out that architectural training was not entirely wasted.

Tuesday, October 20, 2020

Rings a Bell?


Very satisfied to see that the outline of this vehicle is not unlike that of my own, especially after the transition to forward flight. In fact I had given some thought to rendering the side-panniers in the shape of aerofoils, but assigned it to the back-burner as a mod too far at this earliest of stages.

Good news too that it has only four (instead of our eight) propellers, which reinforces the public perception already established by the likes of DJI that to all intents and purposes these things tend to fail systemically if at all, and not as a result of individual power-plants.

Nonetheless knowing how often electronic speed-controllers fail given the power driven through them, I won't be getting in that box any time soon lest I end up in a brass-handled version.

Monday, October 19, 2020

Sturm Und Drone


The situation vis-a-vis regulation of large drones ~ those large enough to carry people ~ within the UK is confused, and confusing. Traditionally the ranks of the CAA were drawn from among the RAF, who taught me the rudiments of flying (G2626048, Sir!). Training in the RAF is so structured that those with the highest marks are streamed onto fast jets, whilst the remainder are guided toward transports (best for joining airlines) else helicopters (best for avoiding a desk).

With the RAF having altogether less interest in helicopters than the British Army or Royal Navy, they've long formed more of a side-show than the main event. As a consequence, the CAA were never overly interested in rotary-winged craft or indeed hovercraft (for which a pilot-license was nonetheless a requirement).

"Drones" in the traditional sense of the word ~ if the CAA had heard of them at all ~ were jets with the cockpits cut-out which were flown by radio-control and shot at by naval aircraft.

As a consequence, when what the public know as as "drones" came along, the CAA would remain all at sea, staffed as they were by ex-airline captains and/or fighter-jet pilots. And in the way the lunatics might take over the asylum, we had suddenly a situation were the average teenage nerd knew more about the subject matter than those supposedly tasked with regulation.

And don't get me wrong, because Arduino is as foreign a language to me as Swahili.

What we need therefore in the UK, with the advent of eVTOLs in particular and people like me showing other people how they can be put together in your garage and flown without the CAA either knowing or wanting to know, is to start a conversation... and so here we go.

I don't anticipate an answer to the question I put to them regarding operations within ground-effect, because the answer would most easily be answered in the courts, given that law in this country is a question of precedent over statute. Nonetheless one of the easiest ways of kick-starting experimental aircraft like my own is to limit experimentation to below ten feet, in a way they eschewed operations of either ground-effect types or hovercraft.

For the time being however (and we really do need a nice flow diagram) it does appear that I can conduct radio-controlled tests with the benefit of a waiver from the normal requirements of the Air Navigation Order, by doing so through the Large Model Association.

This itself came about because radio-control servos got bigger along with IC engines and micro-turbines, whilst the transmitters got altogether more sophisticated too, and all of a sudden you could build a scale version of a fighter-jet that to all intents and purposes might be more manoeuvrable than the real thing.

We long since ceded development of larger fixed-wing drones to the Americans (whose products the RAF use) and smaller multi-copters to the Chinese (whose video platforms everyone uses), and yet we still have the makings of a niche when it comes to kit-built multi-copters able to ferry an individual around the sky at no great cost.

It is this tricky path that I have now to navigate, and having steered many a Boeing or Airbus through many a thunderstorm, it's something I feel I'm up to ~ a Pathfinder Squadron leader, if you will?

Accordingly I await news of my application to operate a 49 kilo radio-controlled model with the blessing of the LMA. And whilst we wait, here's a photo of a magnificent 29 kilo Blohm and Voss BV-141 to relish!

Meanwhile the debate over regulation itself drones on, as you can see here:


Don't be in a rush to condemn the CAA however. As the UK slides toward its bright new future of Third World membership, bear in mind that all quasi-governmental bodies are desperately short of... well, bodies.

Sunday, October 18, 2020

Highs and Lows


Hard to see how this is going to be pursued in the UK, where no avenue really exists for the sale of electrical multi-copters capable of lifting individuals, unlike in the US.

Nor is there an avenue for government-funding for garage-based developments, as once existed in the form of the (long-since privatised) BTG, or British Technology Group as was.

If though you can afford a staff dedicated to pursuit of the 'pork-barrel' however, you're quids in.

Thus Vertical Aerospace (whose owner is down to his last two-thirds of a billion) has just been granted a further £2.3 million by the taxpayer, whilst further funding has flown in Wingcopter's direction from the UK Space Agency.

Why would a UK space agency disburse revenue in this way? Apparently because the drone uses the US-developed GPS system... on which basis the guy delivering my pizzas qualifies for a grant. 

And don't be fooled by the Union Jack on the tail... it's about as British as Volkswagen.

Meanwhile regulation of the largest drones in the UK is suspended after a visit from Australia of Airspeeder's 'flying racing-car' which crashed during practise for ~ and again at ~ a public event.

This resulted in some 230 kilos falling from the sky, as any quadcopter would following a single failure of any of countless components.

Fact is, when Elon Musk said the US was the only place in the world where the future is realised, he wasn't far wrong. Nonetheless we have to work with what we've got, and as of tomorrow I'll make this venture fly by hook or by crook.

Meanwhile to cheer myself up I watch a Scandinavian noir-movie about an entrepreneur who's about to make it in Copenhagen, when he's dragged down by bureaucrats, estranged from his rich fiancĂ©, fails at bringing up a family in Jutland and then dies of cancer.

Felt much better afterwards.

Thursday, October 15, 2020

Who's the Dummy?


Spent more time and money clothes-shopping for this guy than I have for myself this year...

Tuesday, October 13, 2020

Lockdown


A day of mixed emotions, yesterday.

Between the three of us we fitted the propellers and got the telemetry configured, whilst that one of us who owned the barn insisted on a strap-down test prior to letting 'loose this dog of war'.

In this following scene, given a degree of freedom the vehicle strained like Frankenstein at the straps and lifted ninety pounds of timber like it wasn't there.

Given the constraints of the surrounds we were unable to go much beyond a temporary hover, which means that a test-flight in the open air awaits another day.

At around 50kg in weight, however, it has to be classed as an experimental aircraft in both the UK and US.

Ironically in the latter, were we to climb aboard with the transmitter in hand, we'd be good to go.

Saturday, October 10, 2020

Bring Him Home


Dodging the showers I collect the prototype, whose avionics occupy the centre-section, power supply the lowermost drone and both GPS and compass feeds the upper.

Eventually I would like the drones working independently and yet in concert, a little like a duet. At present, wired (albeit beautifully) as they are, they are more like Siamese twins.

It would mean a hierarchical system of flight-control with separate processors top and bottom.

I'd a notion that the octopus has two brains (in fact it has nine) and wholly overlooked the fact that the average human has effectively two brains, albeit linked.

It's not a bad corollary for the logic of systemic redundancy however, as human beings thriving after the loss of one hemisphere of the brain are not unknown.

There's even a term for the deliberate removal of one half... hemispherectomy.

Thursday, October 8, 2020

EHangups


I ask my eight year-old son whether he prefers EHang's drone to Daddy's and he laughs out loud. "What, yours instead of the one with Lamborghini seats?"

Kids can be so cruel at times...

Monday, October 5, 2020

Any Which Way


I file this gorgeous render by Richard Bache (https://carimet.com) as a registered design, which I do from time to time if only as the basis for the inevitable TED talks once I'm lauded to the tree-tops by the world of rotor-craft.

For a long time ~ principally before I realised my cousin was a dab-hand at SketchUp ~ the way we did this, and the way it's done it here is that a photo of a scale wooden model is photographed and used as a basis for drafting.

This has had the very obvious benefit of me having to produce the scale model, which is wholly instructive in itself by providing a 'look-and-feel' before scaling up to full size.

What this one tells us however is that these 'flying wheelie-bins' that I am currently in process of prototyping in flying form don't much care in which direction they're headed.

This will be of more consequence when it comes to extended boxes that you can sit in, but for now and for a variety of reasons the way it is oriented here...


... will do just nicely.