Re: Solution

Yesterday I couldn't get out of bed, and resolve never to design or patent anything ever again but rather to draw on the inventory of a lifetime with whatever time remains.

From hereon it has to be about getting out and having fun with what we've got, so I impose a design freeze after satisfying myself that this is something anyone can make.

I'm under no illusions that what while individuals can set balls rolling, nothing can be achieved at scale without teams ~ the best comprising strangers you've never met but who volunteer without needing to be volunteered.

Accordingly the outline above is as simple as it gets, and can be constructed with off-the-shelf material from DIY stores or else with carbon-fibre tubes and sheet joined with stock connectors.

The prototype here is foreshortened to 6' for indoors, but otherwise is based on 2' x 4' ply sheet and timber spars of regular dimensions.

A prosperous New Year to all of my readers, although I loathe forcible revelry myself.

Lose the Boat

As if to demonstrate that cats need be no wider than monos excepting the arc of each propeller, I replaced the original centre-section of one of the two test-types with that used previously in the mono... rigging the propellers to check clearance still obtains.

I figured the craft would look too narrow, although it actually does not. It's three times as long as it is wide, and whenever I have produced models in the past they appeared to look okay so long as that ratio was anywhere between two and a half and three to one.

Humans have long preferred some proportions over others: the ancient Greeks are the first to have described the 'Golden Ratio' and have used it ever since for sandwiches.

What we're trying to do here though is to produce a watercraft the equal of any other in respect of speed, endurance, range and sea-keeping ability while removing as much of the material involved as possible: still speeding on water, but without the boat.

Strip Search

Steel strip is useful for toughening runners against abrasion from transitional surfaces like decking, grass or even concrete.

There's a wide range of adhesive steel tapes available from the likes of 3M, tho' here I've secured either end with a rivet.

Though previously I used a washer for reinforcement, I found today that the uPVC will support a 4 x 10mm pop-rivet without it pulling through.

Learning by building!

Strike One

Appearances tho' can be deceptive, and the advantage of building mock-ups and wheeling them out for photographs in the northwest of England is that it's often wet or windy, and usually both.

And this is where it literally falls down, and when its windmilling propeller strikes the ground. Still wanting it centre-stage I call my old friend Pythagoras, who tells me that broadly speaking 22" props need a 30" beam to launch from the jetty... which remains on the to-do list.

Whereas the catamaran, besides its many other practicalities, need only be around 24" wide given a little clearance between the two propellers at the rear.

Much then as we appreciate it as a download, we'll set our shoulders to the propeller disk in '25 and resume work on the cat.

Colin will tho' be autographing quality prints at Coniston on New Years Day.*

* He's lying.

One Day...

... my boat will come in.

Off Piste

The author of the phenomenally successful 'Life, the Universe and Everything' was, said his agent, decidedly incapable of capitalising on the success without being goaded and forever in search of 'displacement activities' in an effort to avoid writing... or in my case wiring.

Accordingly I try out much the same framework in support of a mono ski instead of a catamaran. The two-metre chassis weighs 6.50 pounds, or around half, whilst suited to a single motor so long as a rudder is added to compensate for the torque effect. I could of course add a contra-rotating propeller, but that is altogether the heavier and more expensive of the alternatives.

Interestingly the outline dates back to a patent I originally filed back in 2011, and goes to show how technology often catches up with ideas. Thus as the internal combustion engine caught up with our ongoing efforts to fly, the electrification of transport opens up opportunities that at one time looked rather less practical.

All things come to he who waits... though that's true of death too.

Buddy Board

In all fairness to our friends at Lancs Powerboat Racing Club, they were concerned as to how the prototype might be controlled during speed week at Coniston. Especially as with the course a mile long, it'd be out of sight (if not range) as it crossed the line. To my mind this could only add to its entertainment value, though suitably chastened here's my solution for safely testing the wiring whilst ideally wearing a hi-vis tabbard.

I've called it a 'buddy board' and although this is a name I just made up, we shall run with it. In fact made with care it could prove to be a friend for life, with the advantage it won't turn up on your doorstep or need giving a passing thought to.

Representing the flat-cat power-train from left to right are therefore (a) 22v battery-pack (b) speed controller (c) electric motor, whilst centrally located are (d) 6v power supply for (e) RC receiver.

It'll be rigged for differential thrust so that no rudders are required, with the pusher propellers running anti-clockwise and clockwise as viewed from the rear.

The timber was free from the yard around the corner, which wholly suits our budget.