Soliciting your thoughts on C.A.D. for amateur builder

Discussion in 'Boat Design' started by Jay and Ebben, Feb 20, 2011.

  1. Jay and Ebben
    Joined: Jan 2011
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    Jay and Ebben BilgeRat

    I have seen some CAD programs available for boat design and am wondering how user friendly they are and to what extent they can be used. I have manually lofted 4 boats over 30' and enjoy the process but obviously I am somewhat of a neophyte. Is it irrational to think I can take the best of different designs I see and blend them together on CAD, then post them on this site (somehow) and get feedback? I understand the necessity of N.A.'s but I imagine I would incur a HUGE bill if I started out a design process with one and with every question came an invoice. Do any of the programs stand out above others? Are there any duds to steer clear of?

    Some of the programs look to only draw a hull shape. I would like to draw interiors, mechanics, rigging etc. for a 43 foot sailboat. I have no CAD experience at this time.


  2. Squidly-Diddly
    Joined: Sep 2007
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    Squidly-Diddly Senior Member

    I dabble in Solidworks, which is a mechanical design CAD

    It is considered easier to use than Pro-E.

    "Inventor" is the easiest to get started, and would probably be the best for things like boat interiors.

    Their are two distinct things both called "CAD".

    Computer Aided Design and Computer Aided DRAFTING. AutoCAD is DRAFTING.

    I think you want the "Design", which is better for moving parts and doing stress, flow, thermal, etc simulations. You can easily create a metal bracket, and subject it to stress and watch in flex and deform under stresses, which is pretty amazing tech. Same with 'thermal' and heat flow and lost and gain.

    One of the big problems doing designs is combining designs as you mentioned.

    I think Soldworks now has a Photo-Import feature but don't quote me.

    Last seminar I attended some professional Solidworks users said the old 'tape the paper print out to the screen and trace' was in common use.

    You can exchange mechanical designs between the "big 3" of Pro-E, Solidworks and Inventor, but I don't know about things like Freeship.

    You can get a Student Lic# for any of the Big Three CADesign programs if you are a registered student at any Jr College or other college. Yes, that includes taking just one gym class or something. I just got another one year lic of SW for $99.

    These programs have a pretty steep initial learning curve.

    The biggest problem is understanding "where you are" in the program in the various modes....sketch/drawing; extrude/feature; etc.

    Click my handle for some Solidworks boat designs. I didn't use any 'organic' curves except for the outline of the deck. Everything else is "loft, bevel, chamfer"
  3. yipster
    Joined: Oct 2002
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    yipster designer

    why dont you start with a pencil? cad, whatever cad, takes you weeks to learn at best
    if you still want to do it yourself and save cost you may try freeship for a start
    look at the website and check the many boots drawn and ready to download
    and dont forget to read the manual a few times before asking funny questions

    maybe more important: read this forum, designing a boat is more than drawings

    but good luck to you, yeppin and drawing boats is what most of us do here
  4. DCockey
    Joined: Oct 2009
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    DCockey Senior Member

    Squidly-Diddly makes a good point about the difference between "drafting" and "design". Also, there are many different approaches to hull design using design software. Lack of previous CAD "drafting" experience may be good when learning CAD "designing" because some of the fundamental ways to approach design are fundamentally different.

    I've been using Rhino for hull shape explorations. It's also quite popular for interior and exterior design, and I don't know of any reason it couldn't be used for rigging. Rhino appears to be widely used for boat design. I can have an initial hull shape in 15 minutes to a couple of hours or so. Recently I've been comparing a number of different Maine peapod designs starting with published offsets. It now takes me less than an hour to imput the offsets and obtain an initial set of 3D lines. Another half hour or less for an initial surface if the lines are close to being in agreement and reasonably fair.

    The Rhino folks provide several excellent, free tutorials on the basics of Rhino and using it for general design which I strongly recommend. It is very helpful to understand the fundamentals before trying to do serious work. Learning to use software such as Rhino can be deceptive. Within several hours you may be able to create a shape which looks like a boat. Considerably more time is needed before you can reliably create a variety of shapes and have them comeout close to what you intended. And even more time is needed before you will be efficient and able to deal with more complex situations.
  5. Eric Sponberg
    Joined: Dec 2001
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    Eric Sponberg Senior Member

    In a word, yes, it is irrational and a big mistake. Whatever you piece together from parts, you will still end up with having to go through the shaping, engineering studies, and naval architecture calculations to see how the boat will float and perform. Just because you are piecing parts together does not mean that you are piecing construction details and performance bits together. You still have to meld them all together to get a workable whole, and that takes naval architecture and engineering. You are better off starting from scratch, being "inspired" by the other boats, adopting the likeable features, and wrapping them up in design and engineering that works. If you rely only on "comments" from the forum, you will find that you get too much conflicting advice that does not advance the design at all, and does not do any of the critical calculations. You get what you pay for.

    The software is just a tool--it does not do the designing for you--you still have to do that part, to manipulate the programs in order to get them to do what you want. If you don't want or don't have time to learn how to use programs--and they do take lots of time to gain proficiency--then Yipster's advice is best. Go with what you know with pencil and paper, there is nothing wrong with that. If you need help with the calculations, then you really should hire a naval architect.

    Many naval architects (myself included) will quote a fixed price for a boat design for boats less than 60-80' (18-25 meters), hopefully a price that fits your budget, and then the questions and answers are unlimited. I don't charge for separate questions on a major design project. If the client has questions, I answer them, they are all covered under the fee.

    The vast majority of people who under-rate or under-estimate the value of a good naval architect almost always end up building ugly boats that don't work well at all, and they will spend more money to boot for their mistakes.

    OK, I'll get off my soapbox now. I am just injecting a reality check here.

    And I hope that helps.

  6. Jay and Ebben
    Joined: Jan 2011
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    Jay and Ebben BilgeRat

    Thank you everyone for the initial comments. Very helpful - and I will be looking into what has been mentioned.

    My situation is this. I have ten years prior to being able to launch another blue water boat. My kids roll out to college at that time. My 13 year old has a 32' Ericson in the dooryard here that I am helping him overhaul this summer (he bought it for one dollar from craigslist - it sank and has about ten holes in it but, we will have it in the water next summer). In short I have two years of planning time (while I help him) that I am not able to work on my own boat.

    I have included a couple of photos of my furniture work. I feel as though I have a decent eye and am comfortable that I will not end up with an ugly boat or a dog. I am NOT a wealthy person and the finances are always foremost in my mind. When I bought my first boat everyone I knew thought I was insane - yet it all came together and turned out to be one of the highlights of my life.

    Through tragic accidents I lost both my father and best friend recently, which has given me a huge push to make good of what time I have left on this earth. Life is clearly a crapshoot.... and I cannot think of ANYTHING more fulfilling than designing, building, and living on a boat created from my own hands.

    Yes, I would likely end up with aspects that are not perfect but isn't it possible to come up with something that is reliable, fair, safe and sweet? You have to admit.... how many of us push hard enough to pull it ALL together? Joshua to many is ugly.... to me she is incredible, affordable to build, and something I can improve on.

    I am well aware that we are all of different backgrounds here on this board and that is what makes it truly entertaining. It seems that of course one would have to cast much of the advice aside and use what seems most fitting.

    Would there be design tutoring on this site for me with all of the N.A.'s that seem to be lurking in the shadows?

    Lets go!!


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    BATAAN Senior Member

    The #2 pencil with eraser, human's most powerful design tool and the one thing I cannot do without.
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    BATAAN Senior Member

    Rhino is what we used to generate these film miniatures, which had their molds laser-cut from plywood. We made smaller versions first out of thinner ply to make sure the 'kit' would go together in reality and often found hilarious mistakes in the computer (operator's) work. But it's versatile and fast and used professionally in the film trade for 3d work.

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    BATAAN Senior Member

    Buy a boat and go sailing now. It is later than you think.
    -Anonymous cruiser's mantra
  10. duluthboats
    Joined: Mar 2002
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    duluthboats Senior Dreamer


    This question comes up a lot here in many forms. There is a huge amount of information down in the software section of this forum. Learning to use CAD software is like learning a new language. You have to start with the basics and work your way up. 3D is much harder than 2D but once you have a 3D model it will show you many things.
    Is there help here if you want to learn to use CAD? Yes, there are people here with experience in many different software. They are mostly happy to answer specific questions if it looks like you are doing the work. I like Rhino for almost everything 3D, it’s accurate and is priced reasonable. That cost goes up if you want photo quality rendering or marine engineering statistics. Most of the packages have demos to try, which is a good place to start. You might find one that works better with your thought process then others.
    If you post work here you will get a lot of discussion, not all of it will be professional. You will need a thick skin.

    PS ;-) I agree entirely with Eric.
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  11. Tim B
    Joined: Jan 2003
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    Tim B Senior Member

    You need 3 things to learn how to use a 3D CAD tool properly:

    1) The ability to visualise what you're trying to draw.
    2) An understanding of the maths involved
    3) Persistence

    1 takes years, 2 takes weeks and 3 is required for 1 and 2. At the end of it, you have a tool which will help you to describe the now incredibly detailed model you will have in your head. However, what CAD won't give you is the hydrostatic and hydrodynamic properties of the thing you've drawn. That's ok, though, because now that you have a 3D definition, you can export it to other tools to do this.

    As to which CAD package? That's where you need to sit and play with them. It also depends on how you will use it. Do you use direct manipulation of control points to produce a hull (as I do, and I know others do); in which case you will need a tool that gives you that control.

    As long as you approach the project sensibly, you should be able to get a hull-shape you like and specify the basic hydrostatics and powering (based on an assumed all-up-weight taken from similar vessels). At that stage, I would suggest you talk to an N.A. They can then advise you on the full stability criteria and structural design. You will find the advice of a Naval Architect very useful, and most are quite happy to help on a personal project for a small fee.

    Good luck,

    Tim B.
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  12. BATAAN
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    BATAAN Senior Member

    Pesky reality. If the money wasted on ugly, poorly planned, overly-optimistic, poor performing boats could be recovered we'd solve all our fiscal problems.
  13. MatthewDS
    Joined: Mar 2010
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    MatthewDS Senior Member

    As a person who uses CAD daily in my job, here are my 2 cents.

    A working knowledge of CAD can be picked up in about 6 months, and you can reasonably proficient within a year or so. However CAD programs are notoriously buggy, and what sets expert CAD users apart is the ability to work around bugs and solve problems when the program isn't behaving as documented. Starting a large project with no experience in CAD will make you crazy with frustration.

    My advice is to avoid CAD and focus on your sketches. Get a drafting table, pencil & paper, and sketch your dream.
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  14. BATAAN
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    BATAAN Senior Member

    Pencils are cheap and amazingly versatile with few bugs.

  15. Tad
    Joined: Mar 2002
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    Tad Boat Designer

    Exactly as Eric says.........Designing is just deciding how things will be....

    The recording method doesn't matter, it might be a block of wood and a penknife, pencil and paper, 2d CAD, or 3D solid objects......none of these recording (or drafting) systems necessarily produce a superior boat.....the idea that they might is marketing hype from the software just ain't so.....

    Many great boats have been designed with no drawings at's one

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