Designing sailboat on a PC

[Tantribe]

Hello,

I started using autoCAD 2008 and i know how to make plans for a house or any other building. Recently i became interested in designing a sailboat but i don`t know where to start?
How do you begine to make plans for this tipe? Some help would be wery useful... Or if someone has allredy made a hull and would lke to share it`s secretst...

Tan

[mgpedersen]

You should find a copy of Freeship, version 2.6 (it's freeware). That will make the hull and hydrostatics much easier than in AUtocad. You can export the lines you create into ACAD and go from there.

[Gilbert]

Freeship is a good place to start. It's fun, too.
If you would tell us a little more about what sort of boat you have in mind you may get more replies.
www.freeship.org

[Tantribe]

Thank you for the advice on freeship.
I want to make a sailbat that is fast. The tipe of a sailboat that is used in racing, if you know what i mean...

[duluthboats]

Maybe this is not said enough, as an amateur who has a lot of respect for professional boat designers and Navel Architects, there is no software that will design a boat it will only document it for you. Study boat design and AutoCad basics. For high performance boats a you will need lot of experience on real boats.
Gary

[masalai]

There is more to designing a fast sailing vessel than being able to use a cad package. Have a go by all means, make an r/c model to test your "new concepts". Go sailing on every type of boat you can find - - OFTEN - and in all weather. Buy a mono dingy (moth or whatever the local club races) and sail competitively to learn the what & how of fast sailing. For fun and thrills also try beach surf sailing on a Hobie cat or similar.

This is not ********, but a reasonable guide to pursuing your goal - You will note there is a lot of "experience" involved, so you get a good feel for the consequences of your actions in a moderately safe environment. The sea and weather is UNFORGIVING of the foolhardy & stupid, but the rewards of meeting the challenges in a seamanship like manner are great and hugely pleasant.

Many other things also need due consideration, as I am sure other designers & competent contributors will add to this thread. Good luck and have fun.

[tom28571]

Gary, Masalai,

Thanks for the reasoned comments. I hate being the curmudgeon of the forum so need some help now and again. There is another thread that just came on of a 22' powerboat "design" that qualifies for this advice also.

I fear that the amateur boat designer is being swamped by the amateur computer boat "designer". When my son was a little tyke, he would draw boats by the dozen. Even drew harbors with slips to keep them in. He was a sailor and a good one even then and his drawings were probably as practical as these.

More to the point, he knew that they were just drawings and not designs. Getting a computer to draw the lines may fool the operator but does not make a drawing a design.

[Gilbert]

We've done this before Tom, and I mean no disrespect, but you seem to think you are the only one in the world that knows the definition of "a design". So why don't you just tell everyone what it is and we can all forget about what Webster and English or any other language says it is? Please do.

[PAR]

Tom is absolutely correct and I feel it's becoming a problem. I know of a few web sites where a geek designer has "designs", none actually built of course and in really small text at the end very bottom of the page, suggests he is really not qualified to design boats or engineer structures and that "you're building at your own risk". This should have been the headline, not buried.

Software like FreeShip doesn't design boats, it just makes pictures, which provide dimensional views, of a boat shaped objects and the simple math associated with their volume.

What it doesn't do is tell you if it's a good shape or a bad one, though some of the resistance prediction (which is pretty Mickey Mouse) may be helpful. It also doesn't tell you where you need bulkheads, how their placement will affect the structure, nor does it suggest a hull shell thickness or any other engineering aspect of the design process.

If you want pretty pictures, to grace the walls of your "home design studio" then FreeShip is fine. If you want to sail boats farther from shore then you can swim back to, then you need to be an engineer with a few different disciplines and a hell of a lot more in software then FreeShip can offer (you get what you pay for).

[tom28571]

Originally Posted by Gilbert

We've done this before Tom, and I mean no disrespect, but you seem to think you are the only one in the world that knows the definition of "a design". So why don't you just tell everyone what it is and we can all forget about what Webster and English or any other language says it is? Please do.

Gilbert,

PAR defined a boat design pretty well. With due respect to both you and Webster, the dictionary has no concept of what a boat design is. I had no intention of offending the potential "designer" but, rather to let them know what a boat design was not. Others had already in previous posts indicated some of the background necessary to form a design worthy of the name.

No one has an innate right not to be offended and can be assured of being offended now and again. For instance, your comments above offended me and totally misinterpreted the intent. If that were to be the usual response, I would quit making any comments.

[eschwarm]

a good program i use is maxsurf, it gives you the semicirclular part of the hull and you can manipulate it into whater shap you so desire. it also outputs the Cp, disp, LCB LCF etc. There is also a program that goes with it from the same developer, that runs a VPP once you input the rig data and other performance based specifications.

it is really easy to use once you go through the tutorials and quick to make a design.

I feel that the designers who know how the programs run, for example where they make errors and estimates, are the ones who will create a successful design.

[masalai]

OK Tantribe, Freeship is now Delftship. Google either and you can download the free version of Delftship. Most amateurs and a few others on boatdesign use these so there is some net support at no cost except the learning curve. If you run linux, it will work under "wine" but not with the KDE gui/environment.

[Gilbert]

PAR and Tom,
I do not see a definition of "design" or "boat design" anywhere on this thread. So if you have one please do enlighten us.
And PAR, I do not need any software at all to design a boat, and I don't think you do either. So why are you telling an amatuer he needs high end software to do so?

[Pericles]

Gilbert,

The free stuff will design pretty skins, but the the underlying structures are not configured or engineered. Your site demonstrates you do have this understanding. That's a beautiful kayak! However, there seem to be evermore hopefuls posting here with their dreams of being designers, but forgetting that software is a tool like a pencil is a tool. PAR is making a point that high end software does make a reasonable attempt to calculate structures. In learning how to use these dedicated naval software packages, the novice will begin to understand what boat design really is.

It's the education, experience, hands on practicality and high intelligence of Morrelli & Melvin, Tony Castro, John Bennett, John Shuttleworth, Ian Farrier etc, to name but a tiny few, which earns our respect. There are dozens more great naval architects who have more ability in their little fingers than I have in my entire body.

Over the last two years at this forum, I have gained a useful insight into boat building, certainly enough to knock up a decent rowing boat of my own design. Trouble is it looked just like other rowing boats.

I more I have learned, the more | realise how little I know. It's better for me to let people suspect I'm a fake, than post and confirm it Oops!

Pericles

[Gilbert]

It is amazing how in the days before computers your pencil would tell you where to put bulkheads and structural elements, etc. Aaaahhh, for the good old days.