Re: Charge

I've plucked a couple of battery-packs from the conservatory (where if they catch fire they shouldn't take the house with them) and here is one of them on charge. Realise I'm teaching granny to suck LiPos here, but attach the cable to the charger first and reverse the sequence on the way out. Note the charger has recognised that it's a LiPo battery with six (3.7V) cells that amount to 22.2V, so we're cooking on gas. Or electric.

Why do they describe a 2.9 amp/hour battery as 2900mAh? It's really only to separate the geeks from normal people, and to make us buy calculators with bigger displays. But Google says a safe charging rate for a LiPo battery-pack is that same rating, meaning it should take an hour to charge at 2.9 amps. I've gone for 2.0 amps here as you can see.

BALANCE means each of the six cells is being charged in parallel, though it does bear a passing resemblance to my savings account.

Linkin' Park

First step here is to connect the battery-pack, which should produce a red light. You don't want one of these if you're flying airliners, but here they mean that you have at least fitted the connector the right way round. Then simply refer to p.41 of the manual and don't bother me.

This RX has happily been linked before in order to fly one of my super-scale drones. It was done elsewhere, but I know it's good to go because that red light turns green if I turn on the TX and turns red again when it's powered down. Houston, we are looking good...

Are You Receiving Me?

So the second of the recent problems in wiring one or other of the prototype builds was ~ the first being how to upgrade the transmitter's firmware ~ how to charge the batteries for the receiver. Turns out that I should have got a 7.2v six-cell NiMH pack, but this five-cell 6.0v pack will have to do. The charger also delivers seven times the permitted amperage and makes for a charging cycle so rapid that you don't want to go anywhere whilst it's happening.

I also found why originally it did not appear to work as advertised, having attached the connectors the wrong way round (but not letting them know that).

The thing looking like the top-end of a cockroach is a micro-receiver I returned with from the GoFly competition in California at the start of 2020. It took a little searching to find exactly what type, not least because the QR code was defunct, though it should do for the second prototype.

Happy days so long as you discount the prospect of nuclear annihilation.

Herman Hesse wrote during WW2 how artists continued to create much how flowers continued to bloom. I now think this is bollocks, and that crawling underneath a stone is a better response.

Futaban Futility

Developing prototypes, the devil is invariably in the detail. As the RC transmitter has been out of use a while, I figured the firmware ought to be updated. That's done with the SD card, which in turn required an adaptor for an Apple Mac beside a card of only 16Gb capacity... which itself is a rarity nowadays.

None of this worked when it came to the download, and subsequently I borrowed a Windows laptop that did. For whatever reason the Apple appears to unzip the file in process and in doing so, does it incorrectly by skipping the folder that represents the outermost shell.

For all those out there looking to download Futaba updates on a Mac ~ I know there are three of us ~ dropping the UPDATE folder appearing after the download into one called FUTABA should fix the problem.

Frosty the Droneman

With temperatures hovering around zero in the garage, it's no country for old men but nonetheless I remodel the 8' cat to exclude the side-panels to see if that makes much of a difference. Actually it doesn't, so long as two corners of each of picture-frame are braced with steel plates. These sub for tube-connectors that'll be used when I switch to tubular plastic or carbon-fibre sections.

There's a proverb to the effect that fools return to their folly, as a dog returns to its vomit. As if to prove its wisdom I've inset a photo of something I made in a hotel in Helsinki eight years ago while I still flew airliners. Laugh as you may ~ I am hysterically ~ you can see that the same DNA spreads across much of my work. Much like vomit.

Nonetheless eight years ago there was nowhere near the range of electrical equipment that there is nowadays, and drones were toys rather than a better way to do a variety of things... not least eliminating armoured vehicles. 

In time, even dog-sick looks palatable.

Watchkeeper WK450 Mk (and thankfully only) 1:

The Labour government has (along with various other items of the defence inventory) finally abandoned this flying turd. Designed primarily to line the pockets of the military industrial complex in the UK and Israel, its operational use has cost taxpayers not much less than a half-million pounds per flying hour, beside being the best part of a decade late prior to doing nothing much.

Steve Webb Models

Only spoke to these guys week before last and now they've gone... and I once worked with an Emirates 777 captain from Oz who seriously considered renting in Frodsham in order to be nearest the store. Steve however is ill and we wish him a speedy recovery if indeed the condition is recoverable, and thank him for years of dedicated service.

Shopping has, by and large, moved online and what that means in real terms is that the variety of shops that littered for instance a Dickensian high street is gone for good, to be replaced by fulfilment centres that beside being off the human scale are butt-ugly inside and out.

Instead I've had to turn to Overlander, my supplier of choice, to supply a NiMH battery to power the RC receiver, along with a charger and cable to suit.

RC

Nothing associated with projects is ever straightforward, but then neither's life.

We'll use Futaba's 16SZ transmitter to control the flat-cat, as we've done for the half-dozen large-scale drones we've flown prior.

The journey of a thousand miles however begins online, as from the get-go we need to update the firmware on the transmitter.

Futaba recommend a 16GB SD carat I order along with a USB adapter to connect it to the laptop for the download and transfer.

We'll only use the side-stick on the left to control the cat, tho' with 7000 hours flying the Airbus from the left seat, I'll be used to that.

BS

That's a clip from the UK government regards the National Crime Agency's latest push toward... Border Security investment as outlined by the Prime Minister yesterday.

What we're developing is eyes to go to sea. In fact many eyes at sea: a technical hydra.

And in an effort to present as balanced a picture as possible, an extract from Russia's news agency describing further UK government funding for maritime surveillance in the Black Sea.

(It doesn't all have to go to BAE Systems, but the sun doesn't have to come up either):

It's On Tape

A not inconsiderable advantage of using air propellers instead of water is that the cat can be run along the ground for launch, or over sandbanks in operation. To facilitate I recommend a strip of adhesive steel tape be applied to the underside of the skis. They ship in 5m lengths, matching that of the skirting we've used for those skis.

When I worked in airliner simulators it was all about using 'commercial off the shelf' solutions (COTS) for building such devices, for if you didn't then you'd be leapfrogged by people like Loft Dynamics... who claim to cut the cost of training by ten or twenty:

https://www.loftdynamics.com/

Much as I love them, incidentally, by from the original suppliers to avoid B & Q's 25%.

LoL

Final round of the League of Legends world championship taking place in London, and a sponsor is Mercedes. Change creeps upon us all unnoticed, but two takeaways from this post:

(1)    Computer gaming is the world's most lucrative form of entertainment bar none.

(2)    The internal combustion engine is on it's way out.

The latter is a source of regret, and for my son vehicles with such engines are like how steam-powered traction engines were to me.

Ironic though that while auto-manufacturers are having to down-size drastically in the land of their birth, the very first in the shape of Mercedes ends up providing altogether different forms of driving seat.

Mounting Stress

In the event fitting the motors proves to be less hassle than fitting the tins, and here's the proof. I'll suspend the motors so that the props are largely protected from damage and the four of them will be pitched about the C of G, allowing the boat to be flown in free air as a quadcopter but also in ground-effect like a hovercraft. In this last case propulsion may be provided by the cruise-motors at the rear, using less energy in view of the fact that the lift-motors then need make fewer adjustments to RPM.

Am off now for a well-deserved tuna sandwich...

Motor Tuning

For our 'flying boat' mock-up, as in the past I simulate the power-units too, invariably with tins of tuna which match the look-and-feel of U7 motors.

This has two advantages in that it avoids damage to the originals, plus you can make a sandwich with them after the shoot.

N.B. If you are mocking up your own build, note that tuna comes in spring-water, brine or oil and that any of these variations will address our needs here.

Hexcel... lent

My travels take me to Hexcel's manufacturing plant near Cambridge, and my attention is caught by a poster opposite the caff. The reason I'm interested is that laminate honeycomb panels make for the ideal material for the deck and sides of the flat-cat.

The UK side stems from the efforts of a Dr Bruyne in pioneering glues for aviation in the 1930s, so that for instance De Havilland would laminate plywood and balsa core for the Mosquito. His company would be taken over by CIBA, the Swiss firm into glue, and together they would be acquired by Hexcel in California.

Two things of note here, in that Hexcel not only provided the material for the feet of the first craft to land on the moon, and also in so far as their first product was to be incorporated in snow-skis. Besides this, the 747 was the first to feature honeycomb in its cabin floor, whilst the round-the-world Voyager designed by Burt Rutan used such material extensively for its stiffness and levity.

Such things are all around us ~ and underneath us when we travel by air ~ and I am sure that there is a home for them in the flat-cat. You saw how we laminated core foam for domestic use with a hardwood ply from a company in the UK Lake District, and honeycomb might mean that sooner rather than later we may not need to.