"...It looks like I am going to have to get my head around a CAD program...."

What we need is a CAD program you don't have to get your head around...that is free...

DG, I'll take a picture or two of the Marinecraft models and let you work from there.
I would think a good compromise would be to cover harder balsa with 1/64th" ply or even a cheap veneer. veneer can be had cheaply from ebay. Get steamed (Swiss) Pear and you have scale mahogany. Always sanding seal first , THEN stain the finish, never the wood. That would prevent knock damage and help with massively increased strength and still easy cutting.

Martin
Look out for some pics, when I can reach the Marinecraft!

"I am a great fan of the Eezebilt method and ethos, but I despise balsa wood! ......"

True, for an expert! It has advantages for starters, however. It is easy to cut, easy to glue, and easy to mend and remodel when things go wrong. Which is why these simple boats are done in it.

I'm thinking of skinning this corvette in bass wood when I make it. Another problem with balsa is the difficulty of getting a good paint finish on it, and the tendency to dent if touched...


".... and then I have plans to build a Vulcan ......"

What size? We all hope it will be BIG!!??

"....I do have a couple of Marinecraft models which are very Eezebilt in style. An open and a cruiser style. ...."

For the cruiser, do you have the 'Cormorant' superstructure? If so, can I have a scan or photo of it?

Thank you DG,
Well explained.
It looks like I am going to have to get my head around a CAD program.
I am still looking for a CAD program for a complete dummy.

Martin.

Thank you Martin,
I think I understand that better now.
Measurements taken from known Datum lines/marks.

Martin.

Martin, tables of offsets are rather like a land surveyor writes down. Because a boat is generally a curved shape in every direction (even more so than some aircraft shapes) it is necessary to divide it up into regular sections and then measure those at equally regular spacings from a datum. That way you get a frame shape which is effectively the shape of the boat in cross section at every regular spacing. 1 or 2 feet from the stem head, all the way back. As long as the boat is set up level, you can take measurements from a fixed datum (say the centre line through the length of the boat or a wall that is parallel to the keel) to any major point such as the deck edge and chines. You need a vertical measurement too which would usually be the floor.
Where these measurements cross is where the dot goes. Eventually, for each section, you join the dots, so to speak and you get a shape, per section. On the Thames Slipper launch, Freebody's boatbuilder, who had worked at Andrews (where slippers originated) lent me the original table of offsets, from which I was able to make frames. Despite the svelte look of a slipper they are actually all straight lined sections/frames, except frame 1 because you can't twist the plywood quite that tightly so there has to be a slight curve in that frame. Also frame 2 is 1 1/4" out on the starb'd side! and every boat they build has an extra bit of oak added! As indeed I had to on the model.
When I asked the Freebody kids who now run the firm since kindly peter died if I could borrow them again they abruptly refused, proving the son is so very often not what the father would have hoped.

Martin

Hi Guys,
Please don't get me wrong I am not trying to promote the EeZeBuilt web site, (well maybe just a little) it is just that I like the idea that when I am long gone a future generation of model makers might actually be making something that I designed and this system will make it easier to get in to this hobby.
Also what we design now will be vintage later LOL!

Martin.

Hi Martin Westquay,
As I have only scribbled sketches or should I say ideas and built from that, could you please explain to me and the newer model makers what you mean when you said used "Tables of offsets".

I agree with Red with your skills and knowledge.
And maybe we all can learn new ways and could pass on to the next generation.

I think I will have a go at trying to produce a set of drawings for the EeZeBuilt site.

Martin.

I am a great fan of the Eezebilt method and ethos, but I despise balsa wood! Hence any more aircraft would be in foam with maybe a hard balsa leading and trailing edge if I must. So, any boat stuff would be done for plywood as weight isn't a problem in boats as it can be in aircraft. But developing a plan can be very time consuming and I have more than enough on the go currently. Once the Cub is done, I shall finish my Skystreak and then I have plans to build a Vulcan and a Jet Provost. JP is a free plan in Friday's coming magazine and I have a Vulcan plan from the flying club hut which needs making a bit more realistic.

I do have a couple of Marinecraft models which are very Eezebilt in style. An open and a cruiser style. They have identical hulls and only the top hamper is different, but being that pathetic balsa stuff they break all the time.

Martin

Ah, Westquay - then this will be like teaching a grandmother to suck eggs for you...

Expert scale modellers build precisely to a plan, of course, and often match the original construction! Here I am trying to encourage those of us (myself included!) who are less skilled to put their ideas out for others to try. I have always rather liked the simplicity of the EeZeBilt structure, and enjoy fitting it into hull shapes which were never intended for it. It can be an 'Eezy' introduction to the more sophisticated engineering process of doing proper designs....

We didn't present much for the first 'lesson', so I shall follow it rapidly with another little comment - 'Chine Choices'......

Drawing a side and plan view are the standard ways of presenting a model boat, and we had just drawn a hull outline from rough measurement of the photos we have. I continued that by drawing the superstructure, as you can see in 6 on the paper below. Once we have this picture we can look at it and see if the proportions are right. Flicking between the photo and the drawing, I suspect that the bow looks more 'tilted down', and the stern looks larger on the photo - maybe the deck should be slightly tilted forwards? Anyway, let us get onto the chine.

The side view of the chine is easy - just match it by eye. But it can't be seen in plan view unless you are able to photo a ship from underneath, so we will have to do some estimating. We start with the distance from the bow - you can see that indicated on figure 6. Measure that distance - it's where the chine starts on the centre-line, back from the tip of the bow.

Typically, a chine line is similar to the outside line of the deck, but set further back at the bow, and converging on the deck side as you get amidships. That would give you a hull with an overhanging bow and vertical sides. You can see what I am talking about by examining figure 7. The chine line is shown in red. At the front of this hull the cross section shows an overhanging deck (this is called 'flare')- amidships the chine line and the deck line meet and the sides are vertical - and at the stern the chine line is outside the deck line and there is 'tumblehome' with the sides pointing inwards.

Now let us look at the hull we are drawing. The bow looks fairly conventional - but the stern cross-section (from photo - figure 8) shows us that for anti-radar stealth, we have no vertical, and the sides have this odd cranked cross-section. What does this mean for the chine line?

Well, it means that the chine stays well inside the hull line for the full length of the hull. It looks like it is inboard for about 1/4 or 1/5 of the total width of the hull. And the cranked side? That also comes in about 1/5 of the width... I wonder if we could make the two coincide?

At this point we can draw the chine line as in figure 9. And if we increase the 'cranked section' a bit, we can place the chine and the deck directly above each other. I have drawn that in as well - it is the line going straight from stern to the forward quarter. This could make the internal construction a bit easier - which I will start to cover in my next....

Martin WestQuay , you would be ideally placed to design & build a new EeZeBilt 50+ for the site. Why not give it a go when you have finished the Cub..............
Probably last a lot longer too - gave up model aircraft when momentarily distracted by someone had my latest biplane trying to demolish the only brick wall at the flying club (belonging to the toilet facilities) . Wall seemed OK but my prized AM 25 totally disintegrated.............

I've built models from drawings which needed redrawing as they were so bad. I've also done my own drawings from measurements, used tables of offsets where available and just hacked away at 3mm ply by eye!
But a decent drawing helps. My young sons (as they were at the time) helped me measure the Miss Britain III while it was still at Pitsea. The site manager threw me the keys and told me to get on with it! I was sent works drawings for the Riva Aquarama Special, which I was told were like gold dust. Offsets by Andrews' original boatbuilder gave me the Freebody slipper launch. And a tiny drawing in a 1952 Motor Boat Annual I stole from the Pitsea museum library gave me the details for the Darby One Design. I just enlarged them by drawing, being too tight to pay a print shop, who would never have understood what I wanted anyway.

Martin

Hi DG and fellow modellers,

After having a quick look and chatting to DG.
I must admit I am looking forward to following his log, it is a process that I have never seen before and although I have made quite a few models of my own design in the past it looks like you can make a really good model using a simple system.
It has also given me another direction, as when I feel in one of those lazy mood days I could do a little bit of design work for the EeZeBuilt system.

I would be very interested to know if you guys have designed your own model boats and what system/method you have used, no matter how easy or complicated.
Do you just start with a few photos and scale up and build from scratch?
Or do you scratch build from drawings?
Maybe in the back of your minds you want to make something totally different and unusual or like me something totally wacky.

Martin.

Martin and I have been chatting about Eezebilt boat design on PMs, and it seemed like a good idea to take the conversation more public...

In another thread, Red called for people to have a go at designing these boats, and Martin felt that he might be interested if he had any experience of drawing plans up. I thought this might be a good opportunity to show how simple it can be - or rather, how simply I do it! I'm not claiming that how I do things is the way to follow - I'm rather a slapdash modeller - but it might help to de-mystify the process.

Look on this as a build log - it's just that the output will be a set of plans rather than a boat...

Right - let's start. The refs are to the picture I include...

Martin has put together a rather splendid stealth corvette, for which he has some photos, and I'm going to work off these to produce a simplified EeZeBilt version. He tells me that it was about 24"-28" long, so I decided to go with the larger size, and the first step was to draw a 28" long line - see 1! (don't worry about it being indicated at 21" - I shrunk the image a bit to get it all on a single sheet... 🙈 )

Looking at the photos, I can measure the length and depth of the hull, and a little calculation suggests that if the LOA is 28", the depth ought to be 3.25". So now we have 2.

By eye I can estimate the steep angle of the bow, so I sketch that in, and use the 'spline' feature of a drawing package to join it to the keel, as at 3.

The odd stern is again drawn by eye, and then the chine line is estimated - straight from the stern, starting to curve up at about 2/3 along, and joining the bow near the top. Again, the 'spline' feature makes it look neat. We end up with 4.

Finally, we also want a plan view. Note that here we only need half the image, because the hull is going to be symmetrical, and the easiest way to ensure this is by drawing one half and creating a mirror image - again something a drawing package will easily do. The photo measures at 6" beam, so our half is 3" - 5.

To be continued...

Nice model Martin, (and yes we did see the strategically placed recycling bag!)
John B

Hi Red,
I have had a quick look.
Interesting.
I have other projects to finish but I will give it some thought.

Martin.

Currently building a scale Huntsman & Huntress (not both for myself) - struck me that either would make a great EeZeBilt - Huntress probably easier of the two - hands full as there are other boats also needing completion and repairs - anyone else wanting to give it a go?. Can give a pointer to source of drawings ex early model maker etc.

"....I taped some sheets of paper together..."

Exactly what I was talking about. Technology has reached a position now where you can easily have those drawings reproduced and distributed to anyone else who might like to make the boat you have designed, at no cost, should you wish to.

Red was wondering how many people would like to do this ..

i built this a sea princess 👍😁

Hi Martin - RC or you can build static - have a look at Adamcraft & Old Boats too if you can - very interesting . Search in Google finds them quickly. They both have some good plans Dodgy unearthed - look under Model Products in Old Boats for my contribution of the Rhodesian plans.........

Thanks Red,
I will take a look at it tomorrow hopefully.
Are they for RC or static.

Martin.

Hi Martin - this is the site http://eezebilt.tk
check the 50+ challenge for details

Hi Red,
You will have to point me to the web site so that I can see.

Martin.

Hi Martin , the point is you don't have to draw- make a boat the way you did the other - (have a look at the way the EeZeBilts are made on the site) - draw around the finished parts before you glue - mark them - that's it. Scan drawings - send to me to put together for the site. Should fit on about A3 size (420x397mm). EeZeBilts have no plans - only parts and instructions.

Very nice model by the way . Must have taken you a while.

Sorry DG,
Perhaps I should of worded it a bit differently.
What I should of said is that I had no official drawings/plans.
I taped some sheets of paper together and roughly scribbled out the length and worked out the shape of the keel, then the width of the deck.
Then after a bit of tinkering the bulkheads.

Martin.

"...C01 this was made without any drawings/plans..."

Really? I'm amazed! I would have thought you would have to have sketched out something - if only templates for the bulkheads and keel....?

Hi Red,
Very interesting, you may of seen in my harbour C01 this was made without any drawings/plans.
It's a shame that I can't draw otherwise I would possibly have a go.

Martin.

I have, unsurprisingly, been watching this thread with some interest. And I believe that some information can be gained for it even if there are 'no takers'.

Perhaps we could ask how many people would design their own model boats? I had assumed that this was quite common - but with the advent of ready-to-run models perhaps it is a dying art?

What - No Takers ?????????????