Super cavitating very high speed stealth surface vessel

[Bob Abell 2Participant @bobabell2]

As Colin mentioned earlier……..A model behaves differently than the full size craft in the water

Have you taken this on board, to make life easy for us?

I would have thought the Sponsons may need more floatation?………Those 850`s are quite heavy

Are we still having contra rotation?

Don`t think we can have rudders after all, since the legs move through 45 degrees

Just passing

Bob

[Paul TParticipant @pault84577]

As Colin mentioned earlier……..A model behaves differently than the full size craft in the water

Have you taken this on board, to make life easy for us?

Do you know Bob it hadn't occurred to me at all

I would have thought the Sponsons may need more floatation?………Those 850`s are quite heavy

850s?… I thought that you wanted forward running brushless motors

Are we still having contra rotation?

Is this something to do with roundabouts like that one on the A1 at Stevenage.

Don`t think we can have rudders after all, since the legs move through 45 degrees.

Do you know Bob the lack of rudders hadn't occurred to me either, now I haven't got a clue how to steer the thing.

Just passing

Bye Bye Bob

 

Dear Kevin

I must apologise as am fully aware that this represents the lowest form of wit

 

 

Edited By Paul T on 07/01/2015 18:57:14

[Paul TParticipant @pault84577]

Bob

This is the tidied up front elevation

Colin is right about it being very war of the worlds.

And I am sorry for being sarcastic

Yes I have considered the water density, temperature and salinity in my calculations in fact they have been based upon Etherow Lake in June.

At the moment the sponsons are more than capable of providing sufficient buoyancy for 850s and batteries.

There were never going to be rudders as I had envisaged using a tank steering system but at the moment, on paper, the tank steer isn't providing sufficient manoeuvrability so I am thinking about it.  

Paul

Edited By Paul T on 07/01/2015 19:54:05

[Bob Abell 2Participant @bobabell2]

Looks very exciting, Paul

How much gear is inside the sponsons?

Bob

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[ashley needhamParticipant @ashleyneedham69188]

I am missing the bit that explains about the ACTUAL propulsioin arrangement. Does it say somewhere there are contra rotating props?? presumably at the rear.I may have missed this and if so are they in a tunnel or wot.

There are some little "computer controlled fins" at the front of the sponsons to assist steering (initial cutaway drawing) presumably outside the cavitation bubble, could use something similar to effect steering?. Utube video has various test bodies running at 30mph before supercavitation starts. Quite fast….

Ashley

[Bob Abell 2Participant @bobabell2]

Ashley…..All will be revealed in due course

The Maestro is playing his cards, close to his chest, at the moment and will only makes a press release, when he feels happy

In the meantime, I'm beginning to get an interesting germ of an idea, modifying, Brutus and adding some freelance stuff in a similar vein…..But don't let Paul find out!

I hope we do have contra rotating props, they would look awesome!

Over to you, Mr Starter

Bob

[Bob Abell 2Participant @bobabell2]

Paul………Technical observation…..

Why are the legs so long?

We`ve only got to clear the water surface…..Plus a few waves?

Bob

[Paul TParticipant @pault84577]

Bob

The length of the legs are part of the original design and I think that it has something to do with ground effect, in basic terms as the legs close together they set the cabin at the optimum height for ground effect to work. (see Ashleys ekranoplan)

I still have a lot of research work to do in ascertaining exactly how these legs actually work but I will let you know when I have completed my work.

Paul

[Paul TParticipant @pault84577]

Getting back to the design work.

Now that we have clean side and front elevation images to work with.

We can now proceed to work out what the top and rear elevations look like by doing a little basic drawing work in third angle projection.

Its not as difficult as it sounds.

You start with a simple drawing page.

And add the images into the drawing area.

Paul

Edited By Paul T on 08/01/2015 16:26:31

[Andy CParticipant @andyc56856]

I seem to remember us having this conversation before. Still trying. Will go read the Gup B thread again.

Andy

[Paul TParticipant @pault84577]

Hi Andy

Yes it is a bit like deja vu.

3rd angle utilises 45deg lines to transfer points from one image to the one that we are creating.

Paul

[mike farrellParticipant @mikefarrell21522]

Hi Paul ,Please do not say it is not difficult . What you are doing is quiet complicated and requires a high degree of expertise.

As you are aware I am embarking on a course of using TurboCad and a month later could not do what you do with consumate ease

Thor taught me one thing .Let design engineers do the design and follow their expertise with careful cutting and feel satisfied in what I have achieved .

For what its worth I will persevere but will take a lot longer to produce the high standard now being expected and produced on the forum

Keep your standards up and challenging convention Michael

[Paul TParticipant @pault84577]

Hi Mike

Thank you for your comments.

I should make it clear that the example shown above and all other design information that I am referring to can be created quite easily on a sheet of paper using only a ruler, pencil and set squares.

Yes my example has been drawn on CAD but that's only because I find it quicker and easier to use a mouse rather than a pencil.

Many readers (of a certain age) will recognise the drawing style as a corruption of a system that used to be taught at schools during Technical Drawing Classes, although the clever ones amongst you will have also noticed that my 3rd angle style is different to what they remember.

The 3rd angle that I use is actually my own simplified construct based upon both 1st and 3rd angle which makes it easier for none technical people to follow.

I should apologise to the pure engineers like Bob who will find my simple method a little like reading crayon but I am sure they will understand.

Meanwhile may I wish you good luck with your TurboCAD course and if I can help in any way please just ask.

Paul

[ashley needhamParticipant @ashleyneedham69188]

Worm / screw drive to raise/lower sponsons?

I think the legs raise and lower to vary the ride height depending on the wave heights. Obviously the craft needs to be as low as poss for stealth, but the body needs to be kept clear of the water surface.

I would imagine there would be some ground effect lift for the body but the leg thing is purely for the waves otherwise it would be severely limited by weather conditions.

Ashley

[Paul TParticipant @pault84577]

Hi Ashley

Thank you for your suggestion but I am sure that Kevin would like to know how your worm drive actually works without building a huge extension on the top of the machine.

Yes the solution is obvious…………but only the those who have come across a similar problem before.

The calculations do show a significant gain in lift from ground effect but just like the Caspian sea monster it will require constant adjustment to the trim to prevent disaster. I am looking at the gyro systems used in RC Helicopters and Quadcopters as a possible solution to the trim problem.

All ideas and suggestions gratefully received.

Paul

[Bob Abell 2Participant @bobabell2]

Anything to show us yet, Paul?

What motors and prop size are you proposing?

If your model is 44" long, that would make it 4" shorter than Brutus……Just to put things in perspective

If the Brutus Jack mech works ok, we could use the same stuff in Ghost and save a few sovs

Bob

[Paul TParticipant @pault84577]

Bob

The design work continues.

I am still working from the original order that specified 850s, not got to the props yet.

A vertical 'jack' system wont work in Ghost because there isn't sufficient height in the cabin to accommodate the equipment and a centralised vertical mass would create an unstable high centre of gravity. However it should be possible to mount the 'jack' horizontally.

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

Looking very nice and awesome and has got the approval of Brother Geoff too

Will you remove the projection lines………They are spoiling the effect

If you move the plan view to above the top view, the projection would be true 1st Angle and would please the engineers amongst us!

Will you add the main dimensions please……..Length and sponson span etc

Can`t see how a horizontal jack would work?

How did the full size ones work?

Bob

[Paul TParticipant @pault84577]

Just for you Bob I have removed the construction lines.

But as the purpose of this drawing style is to show Kevin that he doesn't have to follow conventional practice I don't want to change the views.

I'm not adding any dimensions yet as this set of drawings are for a small scale prototype version.

Horizontal 'jack' would work in the same way as the vertical except on a different plane.

I presume that the full size boat utilised hydraulics to move the wings.

Paul

[Bob Abell 2Participant @bobabell2]

Will you add a view with the wings in the parked position, please?

Looking difficult compared to the Brutus mod

Bob

[Paul TParticipant @pault84577]

Bob

Ghost at rest.

Remember this is just a first draft of the drawings and I wont be able to give informed information on specific dimensions or details for a long time yet.

Paul

[Bob Abell 2Participant @bobabell2]

Paul

I was just about to put pen to paper, predicting doom and gloom for the Wing elevation problem, when an idea emerged out of nowhere!

Never!…….Yep!…..Sure did!

Imagine the wings with internal arms as the Brutus idea……..On the end of the internal arms…..Simply fix a piece of gear quadrant……With a geared motor driving a small pinion!…..And Bob's yer Uncle!

Have we cracked it?

I think we have?……….Post me a full size drawing of the super structure and I'll do a drawing

A genuine Eureka Moment!

We still have serious problems elsewhere though

Bob

[Paul TParticipant @pault84577]

Design Office to Workshop

Another Q & A memo replies as follows:

was just about to put pen to paper, predicting doom and gloom for the Wing elevation problem, when an idea emerged out of nowhere!

Never!…….Yep!…..Sure did!

Imagine the wings with internal arms as the Brutus idea……..On the end of the internal arms…..Simply fix a piece of gear quadrant……With a geared motor driving a small pinion!…..And Bob's yer Uncle!

Have we cracked it?

 

Do you remember this drawing Bob? It shows the design solution for operating the wings.

I think we have?……….Post me a full size drawing of the super structure and I'll do a drawing

Sorry Bob but as stated in the last posting I cant provide detailed information until I have completed the small prototype stage, this includes full size section drawings because, as yet, I cant predict what the final full size will actually be.

I would remind the enthusiastic workshop of the popular saying about putting a cart before the horse.

A genuine Eureka Moment!

It might be a genuine Eureka moment but only time will tell.

We still have serious problems elsewhere though

The design office can't foresee any serious problems and would like to know which areas are concerning the workshop especially as working drawings haven't been issued yet.

Paul

Memo Ends

Edited By Paul T on 13/01/2015 13:12:37

[Bob Abell 2Participant @bobabell2]

So you don't like the gear segment and pinion idea?

I think you need a drawing!

Your scissor idea is a good mech, but where would it act on the wings?

The serious problems all centre round the sponson drive, motor access and battery access

Bob in the workshop, pulling his hair out…..What bit he's got left!

[Paul TParticipant @pault84577]

Design Office to over eager Engineer

There is no need to pull your hair out… just let the designer carry on with the design and we can discuss problems when they actually arise, as yet I haven't got any worries about designing workable solutions to the items that you are perceiving as serious problems.

I would remind the enthusiastic workshop of another popular saying regarding horses for courses.

Paul

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