Wednesday, July 28, 2021

Backed Fly

I've dropped in at the museum in Oshkosh many years ago, and enjoyed a gala evening at the Hiller Museum as recently as last. What do they both have in common? Each now include among their inventory prototypes of Opener's Blackfly, whose proof of concept is seen first flying (at left) in October of 2011, though inventor Marcus Leng dates the idea to 2009.

Marcus originates from Canada but has moved since to California, in the footsteps of the other great VTOL pioneer, Paul Moller. Both have been engaged over many years in the application of vertical flight to fixed wing types. If only to highlight how far ahead of the game the Blackfly is, the models at centre and right above were constructed in May and June of the following year... I dicking around as ever with balsa and foam at the same time as Marcus was elevating his backside above the lawn.

I only ever envisaged using the configuration in ground-effect (or surface-effect as I'd intended it for water and got as far as launching a half-scale prototype on the Leeds to Liverpool canal). Never in my wildest dreams did I imagine it operating in free flight, and in fact a key element of that is computerised control of the thrust at each point.

For the record, like most foam models this one was decidedly unstable from the get-go and pitched into a somersault given a headwind and uniform thrust applied across all four motors. This in no small part would explain why a dozen years on and with the benefit of Larry Page's input, the fabulous Blackfly is only now slated for sales.

Most inventions are happenstance, and it was Edison who said that no sooner had he introduced another than any number of people emerged from the woodwork to claim they'd had the same idea. Ideas are two a penny, however, whilst the execution is all.

For myself, like most pilots I was never able ever to really choose between air and sea. Looking at these models nearly ten years on, I may re-visit the one on the right as a means of flying over water now things have moved on electrically.

The benefit of the Blackfly's aerofoils are that ~ being blown ~ they tolerate a wider range of pitch angles without separation and stall. Ground-effect's advantages are similar, by its suppression of wingtip vortex, and like vertical flight I fear its siren call as much as ever.

Sunday, July 25, 2021

CGI Fridays

Appears I'm not the only one to have considered the benefits of propellers pitched vertically above and below accommodation, a proposition I've long supported and for which I've produced any number of iterations. I've also been told that I need to up the quality of the renders and feature them in operational visualisations like the one on the left above, so I figured I'd take a closer look at the NeXtuas 'iFly'.

The relevant patent filed back in 2017 does indeed relate to the configuration, though whether it was envisaged back then as a means of transporting people I could not be sure. It may appear in the text but is omitted from the abstract and diagrams, where it would be were it considered the 'killer app'... no pun intended.

The video evidence of it ever having flown as intended is scant, the screen-capture showing it flying with the original skids, which I'd guess you'd have to retain. So many of these eVTOL projects exist only in pixellate form that it's worth the due diligence as investment is generally being sought, but this one does at least have a basis in fact.

As someone who's been there ~ and is still there ~ I would suggest that more tangible evidence is required before either VCs or SPACs are petitioned.

But that didn't ever do the likes of Vertical Aerospace any harm, did it? What they had instead however were financial friends in London, a billionaire owner and a matching investment from the UK government which rarely places it beyond a safe bet ~ and via Rolls Royce if required, which it bailed in '71 and looks set to do again.

Tuesday, July 20, 2021

Karman Ghia

Chance upon the TV news at around the time Jeff Bezos is being launched into space from Texas, and although they cover the launch they don't stick around for a moment more of the albeit short-lived flight in what looks unnervingly like a super-sized dildo. Which would suit a strap-line which reads, "We fucked planet Earth, where's yours?"

In fact Will Lighthorn (sic) who heads up the UK's space endeavour ~ a vanity project if ever there was one ~ says the billionaires are doing us a favour by dumping whatever needs to be dumped in space now that Earth is, like Will himself, full of shit.

This is madness, and something you'd hesitate to call civilisation: the remedy for shit on our door-step being to look for another planet to leave more on... or leave morons?

But the difference between the numbers interested in such ventures now, as against in 1969 when kids stayed up all night, is telling. Literally blink, and you've missed it... which is consolation if nothing else for anyone working in a warehouse instead.

(The views expressed here are not those of the author, but of the author after a glass of Pinot Grigio. He admires every billionaire's efforts to launch humanity into space, or indeed to offer the author a job in his warehouse if things get desperate.)

Monday, July 19, 2021

Epic Fail

I scale up to the 32" cubed that would be required to accommodate the propellers of the same length (real, Jim, and not as we know fascia-board) and can see straightway that the requisite stiffness is going to be more bother than it's worth. Fortunately this exercise has only cost me a couple of quid for pop-rivets, and as Edison said, I didn't fail a thousand times, but discovered a thousand ways it wouldn't work. Answers deliberations of recent days, to the extent underslung propellers remain the way to go.

Sunday, July 18, 2021

Cogito Ergonomics

Looking at the common airframe used in both the underfoot quad posted July 9th of this year and the overhead quad posted two days ago on July 16th, the reason that the latter has the more compact footprint is clear from the diagram above. It includes 32" propellers and a 12" centre-section, just large enough to fit the mannekin's seat.

There's not much space there for dangling your feet, unless you want them sliced like salami. Put the quadcopter overhead and the problem is solved, however. Remarkably the weight of each airframe (the single-decker and the cubic or double-decker) turns out to be the same at 8.40 kilos, but then the former has a 42" square footprint and the latter only 25".

Nonetheless I still figure that upping the footprint of the cubic 'copter to 34" square and using the preferred 1/16th gauge alloy section that I can still bring the airframe in at around 15 kilos, which allows for two battery packs and the motors and ESCs and is still under the regulation 25kg for a regular drone... but without the seat and dummy.

There would though be an argument for getting it flying sans payload, and afterward registering to as a large remote-control model (of which some in the UK exceed 100 kilos under the same scheme). The great benefit of the design however is modularity, in that the drone used in the single-decker version is the self-same that can be fitted up top.

In practical terms this means that the quadcopter can be flight-tested independently and afterward supplemented by either the seat and dummy (albeit with the restricted leg-room), or else raised into the overhead within the outline of the double-decker. At the end of the day therefore it would be for prospective operators to decide whether those propellers are preferred overhead at the cost of the extra weight.

Certainly from the point of view of safety that is the better place for them to be, while at the same time providing for a more compact footprint altogether. What is intriguing about the outline pictured here though is that it would still accommodate a passenger stood within a booth instead of seated, which again is a matter of personal preference. (It also begs the question as to where to fit avionics, though apparently flight-control computers can be operated inverted, so that they might be fixed beneath the base).

It's a dilemma with designing electrical air vehicles though: with helicopters there was certainty from the outset, with their main-rotors above and tail-rotors at the rear.

Now though we are cast into confusion, and Mourning Becomes Electra. 

Saturday, July 17, 2021

Carbon Fever

Carbon-fibre tubing has its advantages in constructing drones. It certainly goes some way to explain the price-rise once you shift from the injection-moulded plastics used in domestic quadcopters toward commercial types dedicated to surveys or to filming for the likes of the BBC.

When it comes to using it ~ as I clearly could ~ for personal air vehicles however, it is much like the choice between buying a Maclaren instead of a Mustang (or in my case a seventeen year old Suzuki Jimny).

For your benefit, here's a rough formula I use to remind myself of its properties:

3 : 7 : 21

This is because compared to (non-aviation) aluminium tubing it is three times lighter, seven times stronger, but twenty-one times more expensive... even given the recent hike in global non-ferrous metal prices.

You could argue that because of that superior strength I could reduce the dimensions of the various struts involved (and therefore the cost) but to some extent that process is self-defeating. For as Brunel discovered whilst building London railway bridges using timber, doubling the depth of material involved alone quadrupled its strength.

In fact it was while I was flying for an airline in Germany, with leisure time invariably spent designing and building, that I was first introduced to a length of carbon-fibre tubing at a light-industrial concern of the kind that the country has in abundance.

I was astonished... light as a feather and unbendable despite being only wafer-thin. It is though useless for the rapid-prototyping on which until now I have been engaged, in which I've used and re-used the same sections of sheet and tubular alloy constantly.

It will happen at some stage, however, if only because carbon-fibre and my airframes were meant for each other:

                                            All I want is a room somewhere

                                            Far away from the cold night air

                                            With one enormous chair

                                            In a carbon-fibre airframe

                                            Oh, wouldn’t it be loverly?

Friday, July 16, 2021

Cubic Copter

With the few props left from the presentation I make a mock-up for my own benefit and it's a testament to the methodology that it's so simple. Specially pleased with the blades, cut from fascia-board that would otherwise be wasted on a conservatory. As helicopters go it looks a lot of fun (of the kind which seems to have got lost along the way). If the weight is kept in check it's a safer place for the propellers, and may yet be the one I choose to prototype at full-size.


With a hundred people viewing the online sales pitch it turned out I was joint fifth on the day, having secured the votes of 6.30 of them. That's statistics for you, but as was pointed out by the organisers ( though many applicants are called few are chosen. Was also a good practise for whenever it might have to be done again, which thankfully might be in person, which is altogether easier and more entertaining. 

Tuesday, July 13, 2021

Let Me Entertain You

'I can't believe we're doing this' says Monty, 'You frekin' owe me one, I tell you.'

We're stopped in the pouring rain for a cup of tea and a Cornish pasty, enroute to the studio where we're all set to do our online presentation.

'Best foot forward!' I tell him.

'Yeah, from the guy who's got legs that move.' he replies.

You can see the PowerPoint presentation here:

And watch the event live here:

The TELEDRONE presentation is set to be streamed toward the end of a half-dozen sales pitches, commencing at 16:00 hours BST.

Monty and I will be available for children's parties should nothing come of it...

Monday, July 12, 2021

Go, Colin!

Altogether more significant viewing yesterday than either the tennis or soccer finals in London was the livestream from New Mexico, from whence Richard Branson and three company employees were lofted into space... as a result of which I shall never now be the first Colin in space.

Coming to my aid Jeff Bezos claims they never got there because despite making what Karman himself and the FAA view as space, it wasn't the internationally-recognised 100 kilometres. Though the metric system itself was the first not to relate to anything practical at all beside what was going on in Napoleon's head, so that it's really just people feeling more comfortable with round numbers that meant the bar would be raised to 100 kilometres at all.

Meanwhile Jeff Bezos could better employ his time in the run-up soiling his pants, as anyone else would contemplating seeing Earth from inside a can. And whichever way you look at it, Branson is a pioneer across countless endeavours and can do no wrong in my book seeing as I sent him one of mine and got a nice letter back.

Plus living on Necker Island and flitting between there and Mosquito Island next door, he is the ideal candidate for the type of air vehicle that I'll be proposing tomorrow. He has spent seventeen years and a billion dollars ~ much of it his own ~ getting into space. The message being, don't give up on what you set out to do even when wishing you'd never started.

And why this picture captured from the TV screen in place of any other? As a pilot, I like the fact that this one has brought the spacecraft to a halt with its nose-skid on the centreline and barely an inch off cue. Or should that be 2.54 centimetres?

Sunday, July 11, 2021


Nomadland, and those the Badlands.

I'd just seen Ken Burns' magisterial five-part series on Ernest Hemingway and felt sure I had flown at some point into Rapid City, where the author late in life apparently tried to walk into a live propeller in an effort to do what he managed a little later anyway.

Seems, without checking the logbook, that I had. Checked into a motel where prior to turning in I took a walk around town in the dark and passed a used parking lot where there was a DeLorean the other side of the fence, which at the time was likely worth a lot less than they are now. The motel was near the railroad and I recall those poignant wailing horns and clanking crossings you get in the movies.

But prior to checking in I'd taken a flight, in a trusty Tomahawk, over those badlands at dusk. I suspected then what I got to see Friday evening... that an engine-failure was death or certain injury. The colours though were spectacular, the air so silky smooth that for the only time I can remember in an aeroplane I could trim it for an approach and it flew itself onward wholly undisturbed.

Which could not be said of the radar controller, checking on me from time to time like a mother its ducklings. I wish now I'd thanked him for doing so, as I do on those two occasions when the chances were, two others had saved my life.

Then why do it, fly a Russian roulette over a decidedly bad landscape, albeit with very long odds? For the same reason I guess that people die on motorcycles and fast cars, or in wingsuits or on skis. Because a life in which every minute is predicated on the need to stay alive is really no life at all.

As they say in the film, "You don't want to die with your sailboat still on the driveway."

Nor your giant-sized drone, come to think of it.

Saturday, July 10, 2021

Fine Pitch?

Condensed version of presentation to be pitched online July 13 at 

Friday, July 9, 2021

Personal (Air) Space?

[This and previous four posts feature a slide-show for delivery at a forthcoming event]

Two-wheel types (Honda Super Cub) outsell four- (Corolla) by 100 million v. 37 million.

Global number of bicycles 2/3rds that of cars (1.0 to 1.5 billion).

25 years into car manufacture, horse-drawn buggies still outnumbered cars.

In the same year (1910) there was one horse for every four people in the USA.

Single occupancy of cars & vans exceeds 60%, moreso on the commute.

For an eighth year running, ATVs hit record sales of 700,000 plus in 2020.

Jet-skis form 25% of all sales of powerboats.

US aviation fleet in 2020: for-hire 6k, airliner 7.5k and GA 205k.

What most effects economies… public transport or private vehicles?

What might most effect 3-D travel… airliner, air-taxi, or personal air vehicle?

Why do institutions, governments, airlines and corporations invest in air taxis...

… that are costly to certify, and in many cases appear only on-screen?

'King’s New Clothes' effect, or the fear of getting it wrong.

(Photo from the Depression, when cars were literally reverted to horse-power).

Capital flows to capitalists like water runs to the sea, and the four latest SPACs for Joby, Lilium, Archer and Vertical are ways of making small fortunes in aviation by starting with a large. The reason few investors are drawn to personal air vehicles is historic, with the Jetsons never taking off and the fact a donkey derby is harder to rate than the Kentucky. Nobody was sacked for buying IBM, while in the UK you're least likely to lose on a venture backed by government, billionaires or Rolls Royce, regardless of credibility. But given the history, could you really bet against a market for air-vehicles with sole occupants?

Bold or Old?

Flown a variety of types during course of 15,000 hours, much of it in training roles.

Operated US, European, African and Far Eastern… from whence TELEDRONE (!)

Have seen and doubtless been near death in aircraft… (ref Airbus conference).

Airline cadet fatality rate of ‘60s revisited due expansion of aviation in China.

Number of deaths alone due to aviation since 1970 alone exceeds 84,000.

What of the ’Iceberg Effect’ or ratio of incidents to actual accidents?

Or the ratio of unreported incidents to the reported: ref Wizz, BMI, UFOs (!)

Social media is not real life, nor is what you see on YouTube real aviation, for…

“Below the sea of clouds lies eternity.” Saint Exupery.

What defined aviation in the twentieth century was operational experience, whereas what defines its migration toward electrical flight is theory, speculation and experiment. A fear of missing out means airlines and governments need to be seen engaging in technology with uncertain outcome and thus the prospect of significant losses, notwithstanding the effects of externalities like climate-change or pandemics. As Richard Branson has said, space was not something he’d have got into had he known the costs of doing so prior.

Early Bath?

Design of helicopters, although fixed, is irreplaceable in many niches.

Helicopters have resisted the addition of wings, without which they can still GLIDE.

As can airplanes, to extent engine-failure is more survivable in singles than in twins…

… except in commercial ops, which are dominated by engine-failure training.

Substitution of multiple motors for a large single rotor is thus seductive…

… but specious, as loss of power is less the issue than controlling what remains.

Nascent eVTOL solution has therefore been to add more motors: 16, 18, 32…

… or else wings to restore gliding ability, assuming no glitches in the hover.

Yet 99% of the world’s drones are quads, yet they’re not falling from the sky.

So is it safer to feel vulnerable with fewer motors, or invulnerable with more?

Are so many PAVs vaporware because motors provide only an illusion of safety?

Will that be addressed by automation and AI?

Did PCs ever crash?

For a while it appeared the main rotor, fruit of decades of evolution and operation, could be readily displaced by a motors, batteries and circuitry as costs fell. Rotorcraft and fixed-wing types have always been able to recover from engine failures, given the capacity to glide. Absent that capacity and fail-safe redundancy becomes an issue of adding so many power-plants that the capital-cost savings are obviated, or relying on automation to replace pilots... so what looks easy at the outset turns out not to be.


Wacky Racers

The TELEDRONE team is lean and low-profile, like the machine:

Colin: is an ex-airline captain who designs and builds.

Pete: is an entrepreneur who ventures within aviation.

Alex: is a manufacturer.

Tom: is a patent attorney.

Phil:         is an electrical engineer.

Mat:         is an airline captain and computer-modeller.

Alan: is a video technician and licensed drone-pilot.

GoFly LLC: is a shareholder.

Low Rider

Only UK entrant in the Boeing-sponsored GoFly Challenge at NASA Ames.

Envisioned as a ‘teleportation’ booth inspired by Star Trek and Dr Who.

Originally framed as a flight compartment fixed between drones above and below.

Since developed as an entry-level surface-skimming type for general use.

Flat-pack methodology, fabrication, distribution and assembly.

Lowest feasible part-count, COTS and DIY build philosophy.

IKEA-style assembly for home-storage and recreation.

Combines conventional open propellers with proximity-shutdown safety system.

“A design achieves perfection… when there’s nothing left to take away.” Saint Exupery.

The first mass-produced motor-car in the United States was Olds’ Mobile, lightest and smallest of the eleven prototypes he had developed. Will eVTOL remain the preserve of the well-off, as were motor-cars and airplanes in their infancy, or can we do what Olds did and develop a car that flies, and which can be developed to fly higher and further? Will post-pandemic mobility be dominated ~ in unit sales at least ~ by electrical airliners, air taxis, airborne elevators or personal air vehicles? As the helicopter was a machine in search of an application, is it reasonable to assume that the ‘flying automobile’ is too?

Tuesday, July 6, 2021

Above Us Only Sky

With yesterday's road-trial under our belt, we're off to the studio in Liverpool for the promo shot of the vehicle that I intend to pitch to investors in the UK and US.

I've gone for an IKEA build to suit recreational flight in the US, where regulations are more relaxed and the prospects for personal air mobility better. Nobody will be taking this up to any height, but it'll be a doozy for flying along the seaside above the waves.

It'll be something you can order online for flat-pack delivery and how-to assembly guide, with your choice as to whether you want to pimp your ride with electricals or have us supply.

It's on par with personal-computing, when the likes of Jobs and Wozniak were putting hardware and software together in Californian garages in a pick-and-mix that would eventually coalesce into global manufacture... not so much a PC on every desk as a PAV in every back yard.

The figures are in though, and good news is the airframe is thirty pounds, (13.4kg) the battery-packs twenty-two (10.2 kg) and seat and mannekin a further fourteen (6.4kg).

It means this 2/3rd scale prototype is clear for flights without the payload as a regular drone in the UK and the US (where we've a pre-existing registration). And with Monty and his seat on board, we're still good to go as a large RC model.

Beside all of this there exists a market for GEVs ~ or hovercraft to you and me ~ for which these make the ideal substitute, given they can leap over fences or pop up for a quick gander.

(Note to self to contact the RNLI on this basis, as anyone watching Saving Lives at Sea will notice that boats are great for getting there, but not so good for spotting heads in the water.)

But that's all ahead of us, and first we'll get it flying on display circuits here and there.


Monday, July 5, 2021

Monty's On Manoeuvres

Loving the smell of unleaded in the morning I wheel the 'drone from the hangar for a road-test on the trailer.

We hear later that the Soviets had a lock on us as we stop for a sausage roll.

Like his cappuccino, Monty is shaken but not stirred.


The publication of Leslie Kean's book 'UFOs' in the UK coincided broadly with the US military's long-awaited release last week of the report into most recent 'unidentified aerial phenomena' as they are now called, and for the first time stated that all but one of the one hundred and forty-four sightings could not be explained.

This is belated progress, because from the 'foo fighters' of WW2 onward, UFOs have been dismissed in official corridors ~ publicly at least ~ as weather phenomenon or weather balloons or anything else that came to mind over a coffee.

Leslie Kean is the author behind 'Surviving Death', which most of you will know from the extraordinary Netflix series of the same name. Which is no coincidence, for whereas governments in the West in particular lean toward the scientific method in so far as nothing is to believed until proven, the majority of people don't.

Most people believe in taboos, primitive wisdom, sixth sense, hauntings, good and evil, the likelihood of surviving death and... UFOs. And for good reason, the way you meet few atheists in either a lifeboat or an airliner in a deathly dive. And so It has long been a case of what Margaret Thatcher would have called, 'Nanny knows best.'

The book invites the participation of people who most of us would regard as credible witnesses, including commercial and military pilots. And here again, the fact has long been that such sightings among this community are commonplace, backed as often as not by radar returns. From my own experience in airlines a great number of pilots had either seen, or else knew of someone who had seen, unexplained flying objects. I myself have, but just the once.

And far from being other worldly, it was altogether mundane. So waiting for a train on a platform at Clapham Junction circa 1980 on an afternoon with a perfect blue sky, up there was simply a flashing light source, which flashed for prolonged periods from the one spot and then reappeared in another far removed, but in an instant.

I had already learned to fly by that stage, and knew how conventional flying machines looked and moved, and this was not one of them. It was however an age without even video cameras, but above all no means of collating such reports or doing anything of use with them afterward. I mean, what is a policeman in Clapham supposed to do with an unworldly light-source and a pocket-notebook anyway?

This will undoubtably be why most pilots have not routinely reported such sightings anyway. The author says this is for fear of ridicule, whereas I know that it's more often a case of wanting to go home after a night's flying without filling out yet more forms.

Here's another from a colleague once flying the mail in a turbo-prop the length of the UK at night in the eastern airspace managed by military controllers. He (or rather he and his co-pilot) see a light appear in their twelve o'clock and steady, at a time when landing lights were confined to landing. He queries the controller, who says he has an unidentified target in their twelve o'clock at ten miles.

The light disappears, and Richard (as it was) asks what happened to it? The controller replies to say that it just popped up again, but around ten miles behind their aircraft. And what is interesting about the bulk of the reports in the book is that whenever the UFOs have been engaged as either a visual or real (!) target at close range, they've had the ability either to disengage very rapidly, or else close down weapons systems.

It's hard not to believe that there are superior life forms out there whenever you turn on the TV and listen to a politician, but like the weather it is by and large wallpaper that we can't do much to alter anyway. And in fact the inhabitants of UFOs appear more benign than natural phenomena, not pulling our legs off for instance as we do with spiders.

Taken in the 1970s above Costa Rica, the photo above which also appears in the book is one of my favourites, as it's an early example of photo-bombing. It's from an aerial reconnaissance mission, and got in the way.

As it's developer doubtless said at the time, 'Fuck, we'll have to do that one again...'.

Sunday, July 4, 2021

Breathe... and Centre

Am often asked why not replace the spiral square centre-stage with an arrangement with parallel prongs like an 'H' and truth is, you could; though there are any number of reasons for being happy with your lot.

First and foremost, with its arms spiralling away like a galaxy, this baby looks like it belongs to the heavens.

Secondly it means all the components to which it attaches and of which it comprises are identical, reducing both part-count and ease of assembly.

Thirdly it spreads the load-paths more evenly, to the extent I can stand on this and it barely flexes whereas I am sure that with any other geometry it would inevitably sag.

Fourthly and as pictured here, it more nearly centres the centre-of-gravity.

The latter reduces the 'polar moments of inertia' that incline road and air vehicles to spin... class-action against Porsche anyone? What it does however for multicopters with their four axes of lift is to spread payloads more evenly, which in turn means that all propellers rotate at the same RPM given all else being equal.

There is though a feature here that represents the way personal air vehicles depart from conventional drones, in that battery-packs often address ESCs and their motors individually (as seen prominently at From our point of view it dispenses with power distribution and the messy soldering that goes with it, and reduces both power losses and the chances of short-circuits at the same time.

It does mean ancillaries like the RC receiver or FCC need a separate power supply, but that's something I'll not be losing sleep over. Ideally I would like the assembly at each corner ~ ESC, motor and prop ~ to be swapped out as easily as a racing wheel-change.

(There are several outfits round the world arranging for 'Wacky Races' for these things, and we shall be throwing the TELEDRONE hat into the ring, incidentally.)

Note too that the avionics are pitched beneath the pilot seat, as in airliners. Maybe all those hours I spent there were not wasted after all?

Saturday, July 3, 2021


This is the second fitment of the battery-packs I tried yesterday but at five I decided it looked like a dog's dinner and watched the Euro 2020 soccer tournament instead.

And on top of all of this ~ quite literally ~ Monty's seat still has to go.

I'd reclaimed the avionics suite that we used on a previous eight-motored prototype and parked it at the front, more or less as was. It was a revelation to me that the FCC or flight control computer need not be dead centre, though any place else is of course likely to be sub-optimal. This hurts, as I regard my prototype as about as optimal as people-carrying quadcopters get.

Behind that board are two 22.2v packs that will have to be bussed together in series to double the voltage, prior to connection to the power distribution board (PDB) at the back, where it looks much like a dead jellyfish.

It's what in the airline industry we would have called the Battery Bus, and ideally I had wanted it fixed centrally ~ underneath if necessary ~ so that the run to each motor was around the same length, and therefore voltage.

(Lost to us from school physics is the fact voltage drops over quite short distances, which means our electric hedge-trimmers die at the far end of the garden. This is bad enough, but for Edison it meant that Tesla would build the modern world instead.)

It's a 'back to the drawing board' moment... or in my case, to the back of the envelope.

Friday, July 2, 2021

Narrow ESCape

Took the opportunity now that I've upped the airframe to one metre square to re-rig the electronic speed controllers (ESCs) and in an upright position to facilitate both connecting and cooling. These babies handle substantial currents beside substantial variations in current, and are more likely to fail than the motors.

But having glued them in place, some reached the motor and some didn't.

Where'd I go wrong?

Turns out I didn't, and somewhere along the way I've accrued four with a longer set of leads and four with a shorter.

Whether they emerged from manufacture like this I couldn't say, but you take the rough with the smooth at this end of the scale.

Thursday, July 1, 2021

Welcome to the Megadrone

This has to be the deal clincher ~ at least in so far as building the simplest possible quadcopter goes ~ when it comes to whether we mount the prototype's propellers at the mid-points or the corners of its perimeter frame.

And this is why when it comes to flying machines, operational experience trumps the theoretical. In the debate as to whether eVTOLs are best designed by practitioners of the art or those new to aviation, there's an argument either way: knowledge hinders imagination, but inexperience can let you down with a bump.

As Confucius said, 'Study without thought is useless, although thought without study is dangerous! And can somebody get me a green tea?'

Furthermore if you've been close to kilowatts driving propellers at several thousand RPM, you realise there has to be secure passage between you and working parts. In previous prototypes that I've tested this clearance was nearly absent, and connecting the batteries was much like feeding sharks from outside a cage instead of inside.

And in this case as it'll be my cock on the block, I tell Monty that we'll stick with the outline that we've already got.

A 50/50 Chance...

... of us surviving the next fifty years? Although you could have said that about the previous fifty, or the one before that.

The difference with climate change as against nuclear annihilation is that you see it coming, it's not an all-or-nothing crisis like 9/11 or Pearl Harbour or Hiroshima. It's just that for a while from time to time, places at latitudes of 50 degrees... hit 50 degrees.

(Latitude is not always a reliable indicator and London ~ like Harbin in China ~ should hit minus 40 in winter were it not for the ocean nearby. What is worrying about the weather around Oregon is that it is adjacent to a cold ocean current).

But it all started here in a side-street of London. Trevithick was a mining engineer, and steam-engines were developed to drain Cornish tin-mines of water. This was a circular logic, because it assisted the extraction of hydrocarbons like coal that in turn powered the high-pressure steam-engines fitted to carriages and (more practically) to trains. It also ushered in manufacture, which was previously confined to the water-wheels of Lancashire and Derbyshire.

Around a hundred years later, Benz repeated Trevithick's experiment of a horseless carriage, but used a petrol-engine instead. His wife took it for a spin and introduced a second hydrocarbon economy about the time the Wright Brothers took flight. Again, what made the extraction of oil economical was the fact engines now ran on oil.

Fast forward a further hundred years and you finally get practical embodiments of electrical power for transport, effectively enabled by computer. And again, computers running on precisely the form of energy whose widespread use they in turn promote.

And these things happen in a lifetime. Could I have known when I started working as a young man in London that half a lifetime hence, most of its inhabitants would be walking its streets like zombies transfixed by a screen in their hands and too purblind to notice Trevithick?

And thus the 1800s were powered by coal, the 1900s powered by oil, and the 2000s by electricity whose origin we get to choose.

Or not, as the ancient Greeks and Shakespeare himself suggested here on the stage. We strut our stuff and imagine we are masters of the universe, whereas the universe masters us by sprinkling coal here and oil there which we lap up like kittens.

So what the fuck am I doing here, developing a practical means of electrical carriage?