Banshee is a super light and screamingly fast hydrofoil catamaran.

The project came into being during a discussion at Bobs big Haydock event where the concept of a high speed catamaran with tilting hulls was first envisaged.

The thoughts have been rumbling around in my head ever since and so I have decided to put the ideas onto paper.

At the moment the prototype is just over 750mm long, the hulls are variants of the Brutus design (take Brutus and split it into 2) connected to the fuselage body by aircraft type lifting wings.

Motive power will be brushless and hopefully some home engineered water jets.

More to follow as the design progresses.

Paul

Thanks Dave

Its a good site and the kit is cheap enough to play with.

I'll get my platinum card out

Paul

Colin

Modelling Hooligan….Perhaps but it adds some excitement to the lake side in a form that cant be banned by the elf & safety people

Bob

What makes Thunderbird 10 go any faster than a plank with the same motive power?

The same reason that any boat goes faster than a plank with the same motive power…a decently designed hull, the question should be 'what makes Thunderbird 10 better than any existing high speed boat'

Why water jet?

Water jets are supposedly faster than prop driven craft and they operate on the surface…..besides which I still fancy home engineering my own version.

Why the wobbly rock n roll action?

The tilting hulls will enable the boat to 'dig in' to the corners as the boat turns. Think how skiers takes curves as they travel across the snow…..its similar to how a motorbike banks as it makes high speed turns. The science is all about centripetal force and inertia.

Can we use the existing brushless motors with the prop inside a Venturi?

A Venturi is possibly the wrong description but a 'prop' inside a tube is basically the same principal as a water jet

Can't see any motors on your layout

That's because I haven't developed the drawings that far.

Is this the result of your new medication?

Possibly but didn't some of the greatest inventions of the last century come about as a result of 'medication'

Diede

Black and chrome…….nice idea…..a bit like a 1950s motorbike

Paul

Edited By Paul T on 03/12/2014 15:51:07

Bob

Using the ski edge sounds intriguing but I'm not quite sure what you mean so, and only if you have the time, could you explain your thoughts and include a sketch or two.

Ashley

The reaction time of the tilting mechanism will need to be fast and also very strong as it will have a lot of different forces acting on it.

At the moment I am thinking of using a heavy duty servo in each sponson to manage the tilting equipment, I am hoping that these servos will be fast enough to work in tandem with the steering servos and be strong enough to resist some of the lateral forces…although it has to be said that I don't expect the heavy duty servos to do all of the work and there will be some basic mechanical fixings between the two hulls simply to prevent them from 'doing the splits'

You are probably right about water piercing props being a better option that water jets, I intend to make the fulcrum point of each sponson coincide with the C/L of the motor/shaft arrangement.

This means that the motive power is always in full contact with the water and will work very well with a surface piercing system but a jet drive does present extra problems in needing a scoop arrangement to ensure water is always available for the pumps.

The centre of gravity (or gravities) is more of a problem and apart from keeping it as low as possible I still have to work out all of the different permutations.

Kevin

Sorry about the techno mumbo jumbo and I will try to make things easier to understand as I produce the designs.

There is no such things as silly questions or daft ideas and I welcome any and all comments so please feel free to 'pitch in'

Paul

Hi Ashley

The self levelling devices should work quickly enough………I don't think the reaction speed will be the issue as the major problem will be getting the hulls to work in unison.

After playing around with the design of the centre hull it appears, at the moment, that it is in the best position to work with the lifting wing but this could all change as the design develops.

The design of the sponsons has been through various incarnations to reach their current shape. A surfboard profile proved to be to thin and had the tendency to flip the boat when turning into a wave.

Putting the drive into the central fuselage isn't really an option as it would reduce the motors from two to one and, quite unexpectedly, put the mass of motor/battery in the wrong position. I think that it is more likely that the central fuselage and wing will be glassed over foam rather than the sponsons.

Paul

This is a view showing the aerodynamic lifting areas of the project (sponsons removed for clarity)

The thinking behind using an aerofoil is to provide extra lift and stability at high speed, the aerodynamic shape of the central fuselage also helps provide lift.

When moving at speed the combined lift provided by the wing and hydrofoil should raise most of the boat out of the water leaving only the hydrofoil and bottom edge of the transom in the water.

The hydrofoil is formed as a curve between the sponsons and is very slender so I am thinking of using a laminated carbon fibre to construct the foil.

Paul

Doubting Bob

The sponsons aren't supposed to 'wobble' about.

I intended the drawings to show the problems that could arise if the sponsons are not properly restrained and to demonstrate the forces that would be acting on the hulls.

Paul

Hello Bob

Sorry that is clear as mud…………I'm not very good at explaining things so I must try harder.

Your proposal of a sleek hull with outriders and animated driver is a non starter as your hull configuration would create a trimaran and completely change the basis of the experiment.

Paul