Prototype build of ELLIE

[Bob Abell 2Participant @bobabell2]

Right chaps, we've had an early morning Board meeting and we've decided on some Open Nose surgery, where we make a Silk Purse out of a Sow's ear!

Nothing to worry about, it's all part of the so called fun!

Bob….in the rummage and finish dept

[Bob Abell 2Participant @bobabell2]

Sorry chaps…..It`s not a pretty sight under that sheet!

We don`t want our readers fainting all over the place!

Had to saw, hack and slash and stitch to save the situation!…….The patient is making good progress and should be back on her feet this afternoon.

The design team has gone for a lie down now, having worked all through the night……..The silly beggar!……and I`m not joking!………Such is the importance of our project!

Dr Bob

[John ShireParticipant @johnshire55937]

Hello Bob

The picture is a little dramatic for what must an necessary part be part of the design process its a little like watching a episode of casualty.

A bit like an author you are building the tension to keep the readers hooked and I am certainly looking forward to the next instalment. Was it the lead pipe in the kitchen or the candle stick in the library and who did the deed was is Professor Paul or Colonel Bob

John

[Bob Abell 2Participant @bobabell2]

Hello John

I`m so pleased you like my crazy sense of humour!

As a matter of fact, I`ve still got the little icon for Miss Scarlet….It must be 63 years old now!

I am enjoying the build very much and will be sorry on completion

Thanks for your encouraging post!

Bob

[John ShireParticipant @johnshire55937]

Hello Bob

Apart from being informative your commentary is certainly entertaining and I am learning a little bit more about the design and construction of model boats. Whilst I can follow and understand the building I still don't know how Paul even starts the design process never mind produce such amazingly detailed drawings. Its all black magic to me.

John

[Bob Abell 2Participant @bobabell2]

Hello John

CAD is easy enough, but hull design CAD is a special type of CAD and is beyond me!

Why don`t you try your hand at our described model?………It would be quite an achievment!

I`m sure Paul will send you a keel set for starters?

Bob

[John ShireParticipant @johnshire55937]

Hello Bob

As far as I know Paul uses a standard cad setup and not one of these special ship types but I am sure he can enlighten us.

John

[Bob Abell 2Participant @bobabell2]

Hello John

So that`s why he`s got the nose wrong?……….lol

Bob

[Dave MilbournParticipant @davemilbourn48782]

Working with a standard CAD package is not a problem when it comes to hull design and drawing. It's really just a clever substitute for a pencil and drawing board. The main problem is getting used to the fact that shapes have a thickness. For example, bulkhead #1 isn't just a 2-D shape. It is chamfered along its edges to fit the skins and therefore is a different shape on one side to the other. When you have such a bulkhead meeting a breasthook and a keel/prow – both of which are also chamfered – then you have to cross-reference every section to obtain the correct dimension. CAD makes this much more accurate than drawing it BUT errors are still errors! Cutting out these parts means using the maximum dimensions (plus, of course, Dr T's magic tolerance for cutting and building errors………) and then chamfering back where necessary.
Incidentally Paul uses TurboCAD while I use AutoCAD. There's no "best" program – it's just a question of what you're used to using.

Dave M

[Paul TParticipant @pault84577]

Dear All

After a night of chasing this error all around the design I have pinned it down to Frame 1 being incorrectly positioned on the drawing

As Dave rightly says you have to think in three dimensional terms when designing and it really doesn't matter wether you use paper & pencil or CAD the three dimensional aspect still remains.

In this case Frame 1 ended up being set off the centre line position by 3mm, (or half the width of the frame) under normal scratch building conditions the builder would simply 'fettle' the work to fit but in this case the design has to be fool proof and straight forward.

I am going to ask Bob to 'fettle' this prototype and make it work, firstly because I don't want to scrap what he has done and secondly it will make a superb master class in how to get out of a problem.

Meanwhile I will make some subtle changes that wont change the overall shape but will design out this problem.

Paul

[Bob Abell 2Participant @bobabell2]

Mod to bows…..

Paul

Send me a picture of the correct Former 1 and I`ll try and make mine the same?

Are the two edges of F1 to be in line….concave….or convex?

Bob

Edited By Bob Abell on 14/08/2013 17:12:14

[Paul TParticipant @pault84577]

Bob

Could you take a photo of the bow construction from the front, i.e. from dead ahead looking astern. And could you expand upon the convex / concave request as I am unclear.

Paul

[Bob Abell 2Participant @bobabell2]

Picture one

The front view…….Obviously!

As requested……..

Picture two

The former edges are……..convex

On the original former, these edges were concave

Bob

[Paul TParticipant @pault84577]

Hi Bob

I think that keeping them straight is the best option.

Paul

[Dave MilbournParticipant @davemilbourn48782]

Bob
In order to facilitate fitting the skins, the edges of the former should be dead straight i.e. one line from gunwale to chine line and another from chine line to keel centre line. If they are not then you are asking the skins to go round a compound curve. This is not possible with sheet plywood under normal modelling conditions.
On a different tack, can you please send me a reply to confirm what we were discussing by E-Mail?
Cheers, m'duck!
Dave M

[Paul TParticipant @pault84577]

Dear All

As you can see from the previous posts every new design has a difficult birth and usually goes through a number of different stages before seeing the light of day, the difference with Ellie is that this usually private process is being done in public……and not just the general public but a load of experienced model boat builders.

Although it might seem that I must be a glutton for public humiliation and that Bob is facing an uphill battle with a fast changing design in actual fact I wanted the members of the forum to be part of the process so that they can see exactly what is involved.

I welcome comments from anyone and everyone.

Paul

[Andy CParticipant @andyc56856]

Hi Paul

Why are you sheeting Ellie. Can you not have used planking like other models use?

Just musing.

Andy

Edited By Wraith Leader on 14/08/2013 22:30:30

[Peter FitnessParticipant @peterfitness34857]

I rather like the curved shape to the bow former, but I am assuming you want it straight so as to use sheeting rather than planking, for reasons of simplicity?

Peter.

[IAN_IParticipant @ian_i]

Hi Bob and Paul…..

Great work and very interesting to me seeing all the design problems and the way you are solving them.

One small question if you can spare the time…..?

What is the thickness of the keel ply wood and are the formers the same thickness ?

Will you also be supplying a log of wood / motors/shaft/battery and components, used in build design ?

A great scratch build diary.

Best regards,

Ian

[Bob Abell 2Participant @bobabell2]

Andy

Most Newbies would run a mile, hearing the words………Plank on frame!

Bob the Plank

Edited By Bob Abell on 15/08/2013 10:27:07

[Bob Abell 2Participant @bobabell2]

Hello Ian

The keel and formers are cut from 6mm light ply……Genuine light ply is quite expensive, if you can find it, and Birch ply is very nice but expensive, heavy and tough to sand

I use a local supplier that sells all sorts of stuff , kitchen doors and off cuts etc and very cheap ply

I think Paul will be leaving the choice of motor and control gear to the builder, but you can always copy what I eventually decide on?

It`s the Haydock Show this weekend and will be ideal for stocking up

Bob

[Dave MilbournParticipant @davemilbourn48782]

Bob
Don't go to Haydock THIS weekend………………'cos the model boat show is the weekend after that!
Dave M

[Bob Abell 2Participant @bobabell2]

Wow!…Flippin'eck!….Blimey!

Thanks Dave……You've saved me a pile of aggro, there!

Will get the ply locally now….Can't wait two weeks!

Bob

[Paul TParticipant @pault84577]

Bob has answered most of the questions so all that I can say is that the final set of drawings and instructions will contain a comprehensive list of materials & equipment including alternatives.

Paul

Just back from my favourite timber supplier with a pile of ply offcuts

[Bob Abell 2Participant @bobabell2]

Hi Chaps

Thanks to the timely advice from Dave, regarding the Haydock show not being on this weekend, we dashed off to Frodsham and bought two sheets of 1.5mm ply…..12" x 48" @ £9.00 per sheet

Now for some progress!

Bob

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