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Thread: A Boat CAD Program Useful for Making Plans?

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    Default A Boat CAD Program Useful for Making Plans?

    I'm going to be building my first boat, and I think I can do a good enough job of making my own design, but i don't know how I can take a hull contour and turn it into into a flat shape that will bend into the right curvature. I want to know what cad programs there are that will let me take a model of a boat hull and then lay out a shape i can print and then cut out of plywood. This isn't intended to create or sell repeatable plans, just make a pattern for the wood planking (spare the comments about how it's better to buy used or how it's not any cheaper to build; there will be major corner cuts since I'm 15 and broke and my intention is just to build something that floats and sails for a year or two.)

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    Default Re: A Boat CAD Program Useful for Making Plans?

    https://sourceforge.net/projects/freeship/

    Not too hard to use. And welcome to the forum.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Quote Originally Posted by glasspotatoes View Post
    I'm going to be building my first boat, and I think I can do a good enough job of making my own design,
    I don't mean to be a wet blanket but you'd be far better off acquiring proven plans. Decent plans can be had for very little or free. Plenty of library books or magazines have good plans. You can pick out the craft that suits your intended use and immediately get to work. If you stick with designing your own boat, be prepared for a long period of trial and error and frustration. Boat design is a subtle but complicated endeavor. It's very easy to overlook important details and end up with a craft that is a real dog. You may end up with a boat that floats but is incapable of anything else like sailing, motoring or rowing and may be dangerous to boot.

    Even design pros who do it for a living don't always get it right. A while ago a I built a paddleboard penned by a famous board designer. He went through six prototypes before releasing the plans. Aspect of the board were still not quite right and he went back and corrected the plans. Do you have the money and time to prototype your ideas? If not your chances of going directly from computer to successful boat are practically nil. Leave design alone until you're deeply immersed in the boatbuilding universe. You will have enough on your plate just building a boat.
    Last edited by Dusty Yevsky; 08-29-2017 at 11:48 PM.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    I do want to be completely encouraging, what you propose is very very doable and well you may make a mistake or two along the way but you learn from those mistakes and it will be so much more rewarding.

    I use Delftship to design the hull and unfold the design, I then take screenshots and print to made lots of little models in thin A4 card

    I then need a third party CAD package to turn these into something I could print full size. If you are a student you should be able to get this free. Onshape is a free and great 3D CAD package which may be able to do this but I have never tried.

    The next bit is at https://tinkboats.wordpress.com/2015/04/

    Design and boats are two of the major cornerstones of our civilisation, have fun with you design and enjoy.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    ^ I use Freeship as well, and then export into DraftSight by Dessault Systemes. Both free and will do what you want.
    However as Dusty Yevsky pointed out, you do need to know what you are looking at. Freeship gives you hydrostatic data, and you need to know what those numbers are saying.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    I would totally encourage you to try it but don't expect perfection the first time. I hope that what you come up with won't turn you off designing, building, or sailing. Have a backup plan in case your design doesn't perform as envisioned, that might need to be building a boat from an existing plan or some sort of serial designing/building. When I was 15 I built several boats/rafts that I paddled for miles without any sort of plan whatsoever but they weren't for sailing; too bad I don't have any pictures handy because this was in the dark ages before cell phones and digital cameras. If you haven't ever sailed, taking a course and then getting into as many little sailboats as you can beforehand will give you more of an idea of what you want and a standard to judge your boat by.

    I've used Freeship Plus 3.4 to great success, it does exactly what you want, export curved boat panels as flat shapes for "glue and screw" or "stitch and glue" boats. You cannot automatically build in the overlap needed for glued lap construction. If you need overlap for scarfing a panel this needs to be added manually also. I have been able to do this on the fly, and have not needed to use a CAD program to blow up the shapes to full size. I find them easy enough to loft onto the plywood panel from an 11X17" printout. I wouldn't trust a full sized printout to not be distorted, better to just to locate points on a grid drawn on the plywood, then smooth the curves with a flexible batten. If that's your stumbling block learn how to loft not how to do computer design.

    It took me a long time (couple of years of being at this several times a week) to figure out many of the intricacies of how to work the Freeship control points to get the shape I want and to simulate properly how plywood will bend. If you are planning on a simple boat with a flat bottom and one panel per side you can pick it up much more quickly, but the aesthetics of that don't appeal to me and I like more complex hull shapes. The help file with the program will get you started and is also useful later on but doesn't have everything in it that you need to know.

    Before printing anything you can try the perspective view in Freeship; shade the boat with a single pale colour and then rotate it around to look at it from several angles not represented in the linesplan. Then build a 1:10 or similar scale paper model from Bristol board, which can help you weed out the impossibles and the uglies and the need for gently flowing lines and accurate cutting will quickly become apparent.

    So far I've stuck to rowboats and haven't really tried to optimize a shape for sailing. If you know how to sail already you might have more of an idea, but designing a good sailboat is pretty complex. One has to get the rocker right, as well as the entry, enough beam but not too much, same deal with flare. That's not even considering the placement of the seats, foils and mast or a sail plan. There are a lot of boat shapes out there that are pretty simple and boxy but seem to be well thought out and surprisingly effective sailboats. Designers Phil Bolger, Jim Michalak and Michael Storer come to mind. For a bit more beautiful and complex but still easy to build boats look at Ross Lilistone, John Welsford and Paul Fisher, but there are others out there also. Stay away from intricate shapes with more than 2 strakes per side because the build could take several years depending on how much free time you have. The simpler boats are quicker but even they can take months because you also have to consider making foils, spars, sails, lines and finishing the boat with several coats of something.

    Look carefully at designs you like aesthetically and performance-wise from the design brief. Don't try to get too radical with your own design, stay within the general limits of what's been done before. If you present your design on this forum chances are that it will be heavily criticized by many but someone might have something actually useful to say. I don't usually put anything on this forum anymore until I get the plywood together enough that I know the shape is doable and half decent looking.

    I recommend Michalak's book "Boatbuilding for beginners", it has a wealth of how-to, some simple plans for boats and sails, and also info on sailing theory, as well as transporting and using a boat safely. If you can, read more than one book in the same vein.

    The hydrostatics Peerie Maa mentioned are important. Things such as centre of buoyancy, prismatic coefficient, resistance and stability matter, but the numbers are only relative until you can anchor them to real life performance by either testing your already built boat or by modeling several boats whose performance you already know in the computer. I haven't been in enough different boats to have a good feel for it yet (completed only one prototype so far) and have to rely a lot on this forum. Read anything you can find about any boat designs that are fairly close to what you envision and take the time to figure out which they are.

    In Freeship you can add a designated waterline that immerses a boat to a depth that you specify, then it gives you the displacement (combined weight of boat, gear and occupants) that will sink the boat to that line and it will tell you also how much freeboard remains. What it doesn't tell you is exactly how much the boat will heel or pitch by moving the weight around. It doesn't tell you if you can safely stand up in the boat. You may have a boat that looks great on the computer, but that doesn't behave well in real life. For example, it may capsize easily because there is too much sail area or spar weight high up.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    glasspotatoes, I assume that you are planning a small boat as your first design/build project, something under twelve or so feet LOA. Larger than that and you are gambling a lot of time, money, and effort on an inexperienced designer and an unproven builder - it could be an expensive and discouraging experience. The experienced curmudgeon in me wants to urge you to build a proven design or two before you set out on this design/build path, but if you are not deterred by the words of an old, grizzled trooper from the front lines, this is my advice:

    Design it (the programs mentioned above are all pretty good).

    Build a model (scale at least 1" = 1' - 0" or larger) out of balsa and Bristol board to prove your design.

    Build the boat out of inexpensive materials.

    Good luck; I hope it turns out well.
    Hope for the best, but plan for the worst.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Freeship is a good choice to start. It takes a bit of practice to get it to do what you want, but there are quite a few tutorials out there. Once you design it in 3d, you can 'Develop panels' which will layout the shapes in 2d so you can cut them out in plywood. I did a bunch of designs and printed out the developed panels in cardstock. Then it was a matter of cutting out the panels and taping them together to see it in 3d again. I was pretty happy with one of the designs and went so far to build it to 20% scale using cheap luan plywood from the lumber yard.

    Below is the panels zip tied together to form a 'boat'. Ultimately, I ended up chickening out and buying plans from a known designer because even though I think I had done a pretty good job with the hydrostatics and the scale model hull looked pretty good (to me), I didn't want to spend potentially thousands of dollars on something that might end up being a dud.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    I think it's a great idea. Have you thought about using a model to design it?



    The model I used



    The boat I built (already had the rig.)

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Quote Originally Posted by mmd View Post

    Build a model (scale at least 1" = 1' - 0" or larger) out of balsa and Bristol board to prove your design.

    Build the boat out of inexpensive materials.

    Good luck; I hope it turns out well.
    I'm glad to see that the veteran Naval Architect still believes in physical scaled models. Besides, still fun to play with "toy" boats! This is part of why I love the design process.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Quote Originally Posted by BrianM View Post
    I'm glad to see that the veteran Naval Architect still believes in physical scaled models.
    Make that plural.

    http://forum.woodenboat.com/showthre...d-coble-design
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    I'm all for this.

    I'm 100% in favor of people using some software to design small boats, say <15 feet, spending less than about $800 in materials. Those numbers are not hard-and-fast, just general guidelines. Go to it. If you have any sort of eye for simplicity and elegance in design, you will almost certainly come up with something that will float, look reasonable, and go in the right direction when you pull on the oars or set some sails. Will it be the newest, hottest race design? No. Will it be fun and satisfying? Sure.

    Now, take some free software and design a 40 foot cruising boat? No. That's a whole different thing in terms of expense and risk.

    But for heavens sake, a 12-14 foot, three or four-panel plywood stitch and glue pram or skiff? Come on. It doesn't take a degree in naval architecture to come up with something that will work just fine. If you get something wwrong...like get some lee helm, just move the mast. Cut out the pertners, move 'em, put in new ones. It's not black magic.
    CLC Skerry = "Vingilothiel"

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Quote Originally Posted by galleywench View Post
    Freeship is a good choice to start. It takes a bit of practice to get it to do what you want, but there are quite a few tutorials out there. Once you design it in 3d, you can 'Develop panels' which will layout the shapes in 2d so you can cut them out in plywood. I did a bunch of designs and printed out the developed panels in cardstock. Then it was a matter of cutting out the panels and taping them together to see it in 3d again. I was pretty happy with one of the designs and went so far to build it to 20% scale using cheap luan plywood from the lumber yard.

    Below is the panels zip tied together to form a 'boat'. Ultimately, I ended up chickening out and buying plans from a known designer because even though I think I had done a pretty good job with the hydrostatics and the scale model hull looked pretty good (to me), I didn't want to spend potentially thousands of dollars on something that might end up being a dud.


    That model looks great. What a lovely dinghy. I think you should build it.
    CLC Skerry = "Vingilothiel"

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    Default Re: A Boat CAD Program Useful for Making Plans?

    As everybody else has recommended FreeShip (which is good), I'll put in a plug for Carlson's Hull Design program.

    http://carlsondesign.com/projects/hull-designer/
    Someday, I'm going to settle down and be a grumpy old man.

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    Default

    Quote Originally Posted by P.I. Stazzer-Newt View Post
    As everybody else has recommended FreeShip (which is good), I'll put in a plug for Carlson's Hull Design program.

    http://carlsondesign.com/projects/hull-designer/
    Another plug for Carlsons Hulls. Its far easier to get started with and the files are easily imported into the more advanced freeship. Its a tad tricky getting it to work on windows 10 but the missing file is included in the 2017 edition.

    Sent from my SM-G930F using Tapatalk

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Quote Originally Posted by Alan H View Post
    That model looks great. What a lovely dinghy. I think you should build it.
    Thanks Alan, I spent a good deal of time on it, but I fell in love with the Campion Apple I'm building now (actually somewhat similar lines).

    This model in the picture is still sitting in a corner of my shop and it may turn into a beer tender though.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    I'm going to decent. It's pointless to learn CAD programming for one boat, especially a first boat. It' more important to read yacht design books and study previous designs so you understand then decide for yourself what curve of areas, waterline beam, depth, prismatic, lcb, mid ship section etc is 'right' for what you want to achieve. Plus lofting it out with a batten to get the sheer and plank laps correct usually achieves a better result than a computer line that is more simplistic than a sheer line needs in either 2d or later 3d. You can just line it off with battens and take plank shapes quickly enough without 'unwrapping' a computer model. It's main benefit would be the speed of calculating the relative weight of all the components, but with a small boat with a massive helm weight moving around and especially with fairly symmetrical double enders that's fairly pointless anyway. You'll have a better boat, a better looking boat and a more relaxing time spending 6 months reading books, making a couple of fairing battens and maybe getting a planimeter not looking at a computer screen trying to understand how to use poorly documented semi professional programs.
    Last edited by Edward Pearson; 09-01-2017 at 05:00 AM.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Edward, even with the expense of a planimiter, doing the calculations to check the design is incredibly tedious. Then you have to carry out a Lakenby transformation and re loft the drawings to make it right. Incredibly boring.
    Freeship does it automatically so you can concentrate on achieving the shape that you want.
    Furthermore doing developable hulls for ply construction is tricky on a drawing board, but easy to do in Freeship. If you are going for a round bilged form that is not an issue, you are just left with the tedium.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Glasspotatoes is 15, clearly he interested in design and if someone my age can get the hang of a CAD package I am certain the average 15 year old will find it a breeze. This forum should be encouraging him to try, to make mistakes and learn from the process. After doing it he may decide it is not for him or he may take his studies much further.

    Yes these are all the complexities that areas of curves and proper hydrodynamic data but we all started somewhere

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    Default Re: A Boat CAD Program Useful for Making Plans?

    If he wants to make a powerboat do 9 knots with a Honda 2, he will need to read and interpolate a few books on yacht and motorboat design.

    A computer program can only tell him how much horsepower his boat needs to do 9 knots.

    It's neither the same thing nor achieves the same result.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Quote Originally Posted by Edward Pearson View Post
    If he wants to make a powerboat do 9 knots with a Honda 2, he will need to read and interpolate a few books on yacht and motorboat design.
    I missed the part where the OP said this? Is it on another thread?

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Quote Originally Posted by tink View Post
    Glasspotatoes is 15, clearly he interested in design and if someone my age can get the hang of a CAD package I am certain the average 15 year old will find it a breeze. This forum should be encouraging him to try, to make mistakes and learn from the process. After doing it he may decide it is not for him or he may take his studies much further.

    Yes these are all the complexities that areas of curves and proper hydrodynamic data but we all started somewhere
    Nice, Tink. I would highly encourage Glasspotatoes to think about Rhino at his stage. Give me a call. I'll PM you.
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    Default Re: A Boat CAD Program Useful for Making Plans?

    Quote Originally Posted by Clarkey View Post
    I missed the part where the OP said this? Is it on another thread?
    No. I'm using it as an example of why at 15 you need to read books to understand what matters, what matters most, when and why to achieve a design objective. Modelling tools are secondary and frankly a distraction to him, unless he's now mastered all that. In which case he won't need to model it, or be asking how to, because he will already know it's been engineered right having done some science and not drawn something 'boat like', and just needs to loft it up and build it.

    Unless I'm mistaken a CAD machine won't show him where to put the plank laps in order to achieve his preset curve of areas on a double chine hull. Neither will it inform him to pull the sheer line up an inch or so at the stem and stern due to optical convergence. It probably won't inform him to increase the sheer line if his boat carries a wide beam forward to avoid powderhorn optically, as the viewers eyeball is higher in reality than the 2d image in the middle of his computer screen. As he rotates his hull in 3d will it automatically adjust for perspective as the stern is now 20ft away from the stem, something you can only adjust that sheer line for in real life.

    But if he does all that in build, will that pre cut CAD plank now fit? Will those pre cut bulkheads and centercase fit now the half built boat has shifted under it's own pull of gravity that was absent on the virtual screen? Nope they won't. CAD has it's place (weight and efficiency studies for supertankers or fully engineered kits for CNC like Vivier, Clint or CLC for example) but for small sailing boats it's just a side dish, and a distraction at 15 from being disciplined to take the time to read, master and apply the NA science to be found in books coupled with a considered study of some suitably representative boats.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Even if our OP never picks up a saw to build the boat, learning CAD, and studying the various theories behind boat design and construction will serve him well going forward, and I encourage him to dive in. Whether that info comes from books, design software, try/fail/succeed CAD exercises, or prowling websites like this or others. The benefit is, he won't sit there in math or physics class and say, "Why would I ever need to know this?" He'll already know why he needs to know it.

    I took typing in high school, even though "it was for girls who wanted to be secretaries". Fast-forward 40 years, and a very common method of world-wide personal communication is typing on a computer, even though the number of secretaries has dwindled significantly.

    Similarly, when my son was in high school, it was assumed he would know how to edit video on a computer, just as it was assumed he could type using a word processor. They're both tools to get things done. And they didn't have specific classes in either. When the OP is finished doing whatever he decides to do, he'll have a good knowledge of what skills are important, are a good fit for him, and it will help him decide what to do going forward.

    So yeah, kid, go for it while you have the time and interest, and before the fumes get you. You know, gasoline fumes, perfumes, etc.

    Chip

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Quote Originally Posted by Edward Pearson View Post
    Unless I'm mistaken a CAD machine won't show him where to put the plank laps in order to achieve his preset curve of areas on a double chine hull. Neither will it inform him to pull the sheer line up an inch or so at the stem and stern due to optical convergence. It probably won't inform him to increase the sheer line if his boat carries a wide beam forward to avoid powderhorn optically, as the viewers eyeball is higher in reality than the 2d image in the middle of his computer screen. As he rotates his hull in 3d will it automatically adjust for perspective as the stern is now 20ft away from the stem, something you can only adjust that sheer line for in real life.
    It will draw the curve, and it is very quick and easy to modify the form to correct the curve. A matter of minutes, not days of calculating and re drawing.

    But if he does all that in build, will that pre cut CAD plank now fit? Will those pre cut bulkheads and centercase fit now the half built boat has shifted under it's own pull of gravity that was absent on the virtual screen? Nope they won't.
    Build a strong jig, just as you must if you buy a kit that someone else designed (in cad).
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    A boat designed and built quickly enough to before the interest is outgrown won't be a thing of beauty. Stuff like the impression of powderhorn won't matter that much for performance, nor will some slight flat spots/bumps on the hull. There are some truly ugly boats being sailed to good effect, puddle duck racer comes to mind, maybe Michalak's mayfly for someone who wants at least one pointy end.

    The op hasn't even responded here, maybe he/she hasn't read any of the responses and is already doing something else.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    Nick when you turn aboat over and fit it out, it's just sitting on the backbone, propped. The rocker will change at that point and be a few mm out when you offer up a CAD centercase or a lofted one for that matter. That's why the kit boats have all the centerline structure in place before planking and turn over. But that's a step on from modelling a hull to fully engineering a CAD boat and strongback like Clint, CLC and Vivier do. I should also add that they also have to build a 'prototype' to make sure it looks right then adjust it again before it goes out.

    Fiddling with plank lands to get your curve of areas correct on a CAD program isn't necessary if you just draw it out. You put the garboard to second strake land where that concavity is in your bell shaped curve of areas. The garboard plank does the forward part of the curve, the second plank the next part an so on. Take this Ness Yawl garboard as an example. That garboard rises at exactly the correct place to provide the curve of areas Iain wanted. The concavity in the curve of areas line (like yours) intersects that point exactly. He knew where to put it to define his curve of areas with just a few planks, without any 'trial and error' on a computer screen like you had to, because he understood how the planks and curve of areas interact. He could just draw exactly where it needed to go. It wasn't a subjective creative or artistic decision. It was an absolute point with that number of planks after he'd drawn and established it's curve of areas. There is science and engineering in those plank lap positions, it's not 'just drawn'.


    For sure any skill is worth having. Learning CAD is a techincial tool and technique that's worth having. Go for it Glasspotatoes.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    [QUOTE=Edward Pearson;5332850]As he rotates his hull in 3d will it automatically adjust for perspective as the stern is now 20ft away from the stem, something you can only adjust that sheer line for in real life.

    /QUOTE]

    That would be basic functionality with just about any decent 3d CAD system, even free ones.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    The Ness Yawl above is 7 inches long on my computer screen and is pixillated. When I adjusted my Shearwater's sheerline the model before me to work with was 144 inches long. Thus I had 20 times the resolution offered by any CAD program and I was working in real light and enjoyed all the full resolution offered by the Mk1 eyeball. Iain had lofted it with a wood batten rather than some computer derived curve, so my wood gunwale took the same bend and sweep like a champ. I'm out now as we're getting at each other. To each his own: it's just a boat.
    Last edited by Edward Pearson; 09-01-2017 at 12:02 PM.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    I think that you should try it. Your mark 1 eyeballs may be opened.
    I speak as some one who has lofted on the drawing board, and used lines drawing software with all of the fairing aids like inverse radius of curvature plots to make my life easier.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: A Boat CAD Program Useful for Making Plans?

    For heavens sake, it's a 12-14 foot dinghy. Did everybody read his post ?

    ".....there will be major corner cuts since I'm 15 and broke and my intention is just to build something that floats and sails for a year or two.)"

    He's not trying to build a freaking masterpiece. Seriously, you want him to learn how to calculate prismatic coefficient and get the sheer absolutely perfect, at 15 years old, knocking out a cheap plywood boat to sail around with a polyester tarp as a sail, for a year or two? You want the kid to spend six months or more reading books on design, engineering and advanced math in order to build a plywood skiff to go bang around in the creek with?

    No.

    Just.........no.
    CLC Skerry = "Vingilothiel"

  32. #32
    Join Date
    Dec 2011
    Location
    North East England
    Posts
    610

    Default Re: A Boat CAD Program Useful for Making Plans?

    Well said
    I don't think many people have read his opening post which was his first, last and only post - read what you want into that.

    Our society at large tends to over complicate things that are fundamentally very simple

  33. #33
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    34,109

    Default Re: A Boat CAD Program Useful for Making Plans?

    Well, his questions were answered in the half dozen posts.
    The rest is just commentary.
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  34. #34
    Join Date
    Aug 2015
    Location
    Modesto, CA
    Posts
    468

    Default Re: A Boat CAD Program Useful for Making Plans?

    All the above posts are most informative, and provide an education in and of themselves. Get a free CAD program and design a boat that looks right to you. And build it. Just remember that in the building, as in the designing, you will make mistakes. Don't be afraid of mistakes -- they are just opportunities to learn. Sometimes you learn a great deal from a small error. Be willing to live with some mistakes. Be willing to correct the important ones.
    "... the door was ajar, and the game was afoot." Lawrence Block

  35. #35
    Join Date
    Sep 2002
    Location
    Hamilton New Zealand
    Posts
    3,819

    Default Re: A Boat CAD Program Useful for Making Plans?

    Quote Originally Posted by Peerie Maa View Post
    Me too, I use balsa and superglue for the small ones, and thin MDF and hotmelt for the bigger ones. One coat of undercoat then paint.

    John Welsford
    An expert is but a beginner with experience.

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