POC #11

The keel in place, filet each side with silicone or adhesive and leave to cure.

POC #10

Stick the foam panels beside the outline of the keel... and I've used leftovers here.

POC #9

Cut foam panels of this approximate size.

POC #8

Using the longer length of the deck, cut a pair of 24" (610mm) cross-bars and mark the position of them along with the keel.

POC #7

Pop a 'blow-hole' in the keel to evacuate the air from the back end.

POC #7

 Flip it over and fix the other side of the keel (front end seen here toward left side).

POC #6

Flip the keel over and affix the other side... screws for timber or pop-rivets for tubing.

POC #5

Here's the 1" (25mm) insulation foam sheet cut to suit and glued in place.

POC #4

This is how it will be fixed. If you fill the entire keel-space the craft will not sit level at rest, though with buoyancy allocated in this way it should sit nose-up for launch.

POC #3

Trace an inch (25mm) along the top to as a guide for the foam buoyancy template.

POC #2

Based upon one of the smaller panels, cut two inch-square (25 x 25mm) keel-posts of the same depth and trace their position on the back-board.

POC #1

Here's a guide to building a stock outline of the boat using standard materials off the shelf. It uses universal 24" by 48" sheet of any type (610 x 1220mm) or at a larger scale the equivalent 48" by 96" (1220 x 2440mm): divide into proportions 26/11/11 lengthwise.

Malloy there, me hearties!

What links one of the UK's multi-billion aircraft carriers with a man on a flying motor-cycle? Well back in 2006 Chris Malloy built the 'world's first flying motorcycle', though Evel Knievel might have made the same claim since trying to span the Grand Canyon on a motorcycle back in the day.

Based in the UK, Malloy turned to heavy-lift drones instead with assistance and funds from a US university, and drones such as these are what are embarked on the multi-nation flotilla ostensibly aimed at persuading China not to invade Taiwan (as only the British are allowed to do that sort of thing).

The takeaway from this ~ and something I myself learned at cost ~ is that you can't beat selling something altogether less glamorous to the military because as Jessie J might say, in that event you can forget about the price-tag because we're paying for it.

Accordingly you'll never see rack-rates on websites devoted to building for the military for fear of embarrassment. Suffice it to say that the modestly sized fixed-wing drones the Royal Navy is also taking with them (AeroVironment's Puma) are thought to cost a quarter of a million apiece.

Nice work if you can get it, Rodney.

The pic is of plumber Colin Furze flying his own creation, but see one and you've seen them all...

No Flotation Nation

Static Flotation Test 04-20-25 and (inset) Declaration of War

The locals have reacted to the most recent tests by fencing the facility off and posting warnings around the perimeter, no doubt having emailed the council to say 'There is someone out here not sitting on the sofa all day watching foreigners perform on Britain's Got Talent like the rest of us.'

Fresh from videos of robots in China running a marathon, who'd launch anything here anyway? The PM does his best, but frankly he's putting lipstick on a pig when it comes to enterprise in the UK.

The greatest danger anyway is not so much the three-foot depth of water as that the local slobs throw terrapins in there instead of down the toilet, and they've grown to the point they'd take on anything Florida can offer.

But like Shane my work was done anyway and with the motor forward and battery aft:

(a)    At 11" behind the motor-mount the C of G is aerodynamically reasonable.

(b)    The motor itself is broadly clear of the waterline at rest.

The latter is not that much of an issue anyhow, as you can drop electrical motors into a bucket of water and it seems not to put them off their stride. What is most pressing now is to fit the prop, wire the motor for sound and see if if the thing will rise above the waterline from the get-go.

If that pisses off the locals and council even more, then that can only be a bonus.

Rolling On the Deep

And no Adele, tears are not going to fall so long as we mount our battery-packs as the master teaches us!

Many people have contacted me (Ed. in his dreams) to ask where to mount the battery packs, and they are right to be losing sleep over the issue.

A reason tho' the I abandoned eVTOL aircraft for uncrewed surface vessels is that they are the gift that keeps on giving, whereas the former were more of a gift you'd want to return soonest: for example the aircraft required a minimum of at least six and ideally eight motors to guarantee its safety in the event of one failing, which after dismantling left me with the means to build eight boats in place of one aircraft... and you can't argue with that.

Multicopters also draw huge amounts of energy, requiring LiPo batteries with a high discharge rate whilst the boat can use lithium-ion cells that are used where sustained endurance is required, as in cars and aeroplanes.

Making do with our LiPo leftovers, two questions arise as to where to put them:

(a)    Master, do we submerge them?

(b)    Master, should we fix them to the keel?

Asking the assembled crowd whether they would ever learn, he went from that place and wept (Ed. the guys in white coats are on their way).

We've seen in the past how our 22,000mAh packs should give us a twenty minute run time whilst the 2,900 mAh will provide altogether less... but the former weigh 2600g and the latter just 350g so again for test purposes using the lighter is a no-brainer.

Measuring the larger pack as you do on a Saturday afternoon, it appears to displace a litre of water and the answer to question (a) is that given we'll reduce the apparent weight of the pack by 40% by submerging it, why wouldn't you want to? So shouldn't we fix it to the keel where the greatest mass is normally best located?

Well this is amongst the challenges we must address in designing craft that are half aircraft and half watercraft, for on balance the mass of the batteries is best applied to the centre-line.

For one of the joys of developing the monoski instead of the catamaran is that it is able to bank into turns like a motorcycle... or else an aircraft. Another joy is that the rudder surface acts in conformity with the turn, unlike on aircraft where it applies roll in the opposite direction. (It doesn't in practice because it accelerates the wing on the outside of the turn, but note all surfaces are NOT singing from the same hymn-sheet).

Looking at the diagram above, finally, you can see that fixing the mass of the batteries on or around the axis of the craft allows the rudder to both induce yaw and roll in the required direction. Should we fix it nearer the keel, whilst it still yaws the craft in the way we'd want, it applies roll in the opposite direction (and unlike aircraft there is no wing to compensate for its adverse effect).

R = right rudder application in the diagram

Easter Rising

There's no arguing with the stats, and if there is at all a reason to persist with this experiment then the reaction to the reappearance of the monoski is probably it... a picture that seems to have been worth a thousand views.

Time will tell however if it will get me from sofa to garage.

(Ed. he wore his finger-tips away clicking that touch-pad.)

Sinking Feeling

Wondering what to do this Easter break? Why not throw the kids in the car along with a picnic and head out to the local pond for a static flotation test? Whilst you're there with your waders on, they're having fun in the sun by complaining and playing Roblox!

Here though the replacement of wooden stern-posts (bad) with alloy sections (good, albeit in the ballast department). Note the holes for ingress of water and for its egress once on the plane in order to lighten the mood.

If you like you can fit these with electrical valves, and flood them at will dressed as a U-boat oberleutnant.

Notice they are fitted with 6mm threaded tube-inserts using an Allen key from IKEA. These can be had for free and if you go there, simply ask reception for 'one of those tools for fitting ballast-tanks to a semi-submersible'.

Mention my name though to be sure that they charge you.

Is it a Boat? Is it a Plane?

I've set aside the catamaran in favour of developing the monoski, if only because I've no great wish to steer revenue toward motor manufacturers: not least because (without mentioning T-motor's name) their ease of use is missing in action.

I also consider it has more raw potential, for the outline above could be dropped from the air to glide to a location from where it may operate as a fast patrol boat; which is awesome coming at a time when I see no reasons for getting out of bed.

It is time though to turn to tubes, because these do in fact offer the flexibility of use that timber might not.

For instance most timber is lighter than water (as indeed is the uPVC ski seen here), which is not what you want beneath the waterline: constantly trying to roll the craft upon its side at rest, much like me in the morning. Tubes though can be flooded, so you've the option to use them as either ballast or buoyancy.

It therefore provides an opportunity to flood them whilst shouting commands in the style of Kurt Jurgens at the sight of a Fairey Swordfish overhead:

"Schnell, schnell! Füllen Sie die Röhrchen! Tauchen, Tauchen!!!".

As a child I installed a fish-pond and used it to sink an Airfix model of the battleship Scharnhorst with a Webley air-pistol instead of a six-inch gun (Ed. actually last week).

p.s. Inquiring 'how to order a submarine to dive in...' Google suggested 'Wigan' instead of 'German'.

The Rijks Stuff

I asked my media people (Ed. yeah, right) to look at what we can do merch-wise with the recent image and our AI 'bot feels that it's more Van Gogh than Monet.

Accordingly the above ~ entitled If this doesn't work I'm cutting my ear off ~ has now dropped as a non-fungible token for just £10,000.

As the curator of the royal collection has suggested, 'Beats the Banksy bollocks.'

Dogger Bank

Too nice again not to try out the new waders, and see if they float my boat. The keel has always been troublesome and when unladen the craft wants to settle on its side like a dying whale.

Needless to say I forgot to bring the weights and thus the smaller stone at 300g suits the motor, whilst the larger at 1635g falls between the heavier battery-packs available to me and the much lighter. Suffice it to say that weightier ballast would have to be shifted to the rear to sustain this trim, which is not what we want aerodynamically.

Nonetheless perfection being the enemy of the good, there's always a workaround of some sort or another. Bear in mind everything here is lighter than water, including the superstructure of the keel and the ski, so it's an achievement getting it to settle at all.

The picture's good enough for my online merch (Ed. he hasn't got any), and looks like something Monet would paint prior the tea and cake that I'm about to have myself.

It's called, "Drone at Giverny... and where the fuck are my lilies?".

Profile Pic

Here is how it looks from its best side. A block at the stern is reserved for the rudder, which if retained inboard allows for the boat to be stood upright for storage.

Aside from this displacement has been adjusted by use of a diagonal sheet of foam, which should pitch the motor clear of the waterline at rest.

The keel could in theory be sandwiched by rectangular sheaths of plastic sheet; whilst this would look rather better it would complicate the aerodynamics.

The reason a cat is a simpler build is the total absence of asymmetric effects deriving  from a single propeller. This produces a swirl in the direction of turn that impinges on the tailplane (or hear the keel), rotating the craft around its axis unless compensated.

Conventionally this compensation has taken the form on single-engine aircraft thus:

    (a)    offsetting the engine mount

    (b)    offsetting the tailplane

    (c)    rigging the wings at different angles of incidence

Tricky eh? The only means of compensation available to this bad boy will be input via the rudder.

Whether this will require the speed of a flight-control computer remains to be seen.

Circular Logic

Pursuing what my uni mate used to call 'the path of least resistance', I wonder if the boat could be tested under power but without a rudder.

In doing so I come across a pastime dating back practically a century... now pursued solely by old men in waders.

As I'm signed up to the fraternity on both counts, I look a little closer and it involves running hydroplanes ~ some powered by airscrews ~ around a pole on a tether at up to 100 m.p.h.

On the same day whilst doing what I like to call 'research' on YouTube I discover that the Russians have switched to communicating with drones along lengths of what is effectively fishing twine, in order to avoid jamming... and who knew they had reggae parties anyway?

The above video was taken at Verulam lake in St Albans, a place I knew well when I had money. Needless to say it's been banned there since, as it is a trifle noisy (while middle-class dog-shit isn't).

Accordingly it is now pursued only in Essex or at a lake in the East Midlands. I make a note of the dates and contact details, if only to find out how to fix a pole in the water.

I take my son to things like dog-racing and demolition derbies, simply because going forward the earnest desire of our nation is to be left at peace to watch TV. One of the few pastimes that has yet to be banned, it is also in tune with Labour's ongoing effort to pay people to do nothing.

Eureka!

I visit the static flotation lab ~ which some people insist on calling the bathroom ~ to see how my technicians (Ed. he hasn't got any) are progressing with tests designed to raise the motor clear of the waterline at rest.

Key findings include:

    (a)    We need a new plug because the water-level has dropped overnight

    

    (b)    We need a deeper bath because the rig is occasionally grounding out

    (c)    It appears the strategic distribution of foam does meet requirements

Altogether that's what I wanted to hear from the team, and like Elon Musk I fist-bump them all before departing the lab.

My only concern is that this rig is ballasted by a drill-bit along the bottom edge that you can see in the picture, whilst dead weight is something I want to avoid entirely in the proof-of-concept.

The what-goes-where of foam, ballast and payload however awaits testing of the boat itself and to this end I've bought a new set of waders from Decathlon.

Whether testing takes place under the watchful eyes of doggers and fishermen on the local pond remains to be seen... there are locals who hire their indoor pool for kids' parties and I'm wondering whether that's the better option?

All in all a good end to the week, so I skip the yoga class and eat a doughnut instead.

Re: Boot

If you're German, you'd get that (Ed. 'boot' is German for 'boat').

Did though mock up something like this but stabilised by outriggers, but it was to use a technical term: shite. I thus figured it was not necessary and that the mono could be adapted to suit.

And what appeals about it over the cat is the fact it needs only one motor and given my experience with T-motor's great-kit-no-backup business model, anything that reduces my reliance on electronic speed controllers is good in my book.

(It will though need a rudder, but servos are old hat and I've used them in the past.)

The previous mono having been broken up for parts, this I knocked up in a half-day using leftovers from around the workshop. It's six feet long, two wide and one deep.

As it's half boat and half plane, however, I'm having to design for both contingencies and as you will know, most aircraft have motors (and the C of G) pitched forward for stability. Thus the motor will appear as previously advertised: out front of the deck.

As it stands, the C of G sits around a foot to the rear of the centre-post, where you can see I've balanced the craft on a length of dowel. After fitment of the motor that is likely to be around six inches aft of that leading edge, which is ideal for those times when it breaches the surface like a wooden whale.

We have seen from previous flotation tests that these things sit nose heavy at rest in the water, though I think I've a solution for that which we shall investigate sooner in place of later ~ in fact I've not let the water out of the bath so as to test the notion.

The battery meanwhile represents useable ballast that can be located to adjust the C of G to best suit operation at rest and on the plane, with the benefit that unlike fuel tanks their weight and centre of mass do not alter as energy is expended.

As seen here it weighs 2.90 kilos or 6.40 pounds... one pound for each foot of length, which is not bad comparing to other monohull watercraft.