scale model of prospective build

Discussion in 'Boat Design' started by spaceboy, Oct 27, 2013.

  1. TANSL
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    TANSL Senior Member

    It seems so wrong this perception that I'm not sure how to refute .
    The full scale virtual 3D model allows you to define each part of the boat , fit into a cliché (nesting) and cut by CNC . Allows to draw the " isometric " and bring aboard prefabricated pipes . Same with electrical limes gutters and vents, among other things . And all without leaving your desk. If you also want to make a real model , such as a cabin and its furniture, the computer model allows you to get all the necessary information to do so. So the Owner can view and make changes as needed.
    The virtual model also allows you to obtain data as weights , centers of gravity , painted surfaces, cable lengths and eleven hundred data that with the scale model are more expensive or difficult to obtain .
    It is true that for small boats can be impractical but it seems incredible that , at this time , I have to be defending the computer model .
    I may have to explain , because some do not understand, that a decorative model is one thing while a model made with a CAD / CAM software has many other possibilities.
    One method does not exclude the other, but despise the computer model, frankly, I find incredible.

    Answering now to spaceboy: not only is an accepted practice but I'd say it's essential. You need to select the correct scale for your model to obtain maximum information. 1/12 leads probably to a too small model.
     
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  2. PAR
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    PAR Yacht Designer/Builder

    Again, learning to manipulate a 3D model software package is a time consuming waste of time, unless you plan on making many models, many mockups and can justify the steep learning curve and cost, to do the job well.

    Building a cardboard mockup for a galley counter and opposed settee (as an example), doesn't require any modeling on a machine, just a set of dimensions, pulled from the plans and some basic skills. Moreover, this offers a lot more practical information, than a novice running a 3D modeling program can usually generate. Sometimes you just have to literally live in the space and though a skilled modeler, can imagine themselves in this space, there's nothing better then physically seeing if you have, the room to crawl under the companionway opening, to access an engine bay (again as an example). The costs associated with the cardboard model, compared to a satisfactory 3D package is also a consideration.

    You'd think with all this talk about 3D modeling, we've never been able to design without it, which is just as absurd as suggesting we can't do without it. I don't despise the computer model, but also find there are much faster and cheaper methods, usually without any electronic interface necessary. Spaceboy would be well advised to explore the virtual model end, as his goal is a 70' steel schooner as his first project, which in it self is telling to say the least, but to get a better grip on what's involved the quick and inexpensive way would be a simple scale model. At 1/8th scale, this would be impractical, on a 70' yacht, but at 1/16th scale he'd have a 52" model that would tell him quite a bit. No it wouldn't be as accurate as a virtual version, but I don't think this is the goal. The plans should cover the conduit runs, plumbing and other "details" so why learn a new, often difficult for most, set of 3D modeling skills, when it's not going to help much with the project.
     
  3. TANSL
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    TANSL Senior Member

    I do not want to mention names because this way, apparently, I can say whatever I want, but I think that comment on the advantages and disadvantages of a method, without knowing it, is not very professional.
     
  4. PAR
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    PAR Yacht Designer/Builder

    I'm really not sure what you're talking about, TANSL, names or not. I use both methods, though admittedly I do more virtual modeling then physical mockups, but there's a need for both and certainly a cost associated with both. 3D modeling isn't something you're going to pickup on a weekend, if you expect any level of accuracy or proficiency. It's also not something that necessary if you have a set of plans in your hand. Spaceboy is looking to build not design, so how can you justify the expense and significant learning curve, for becoming reasonably proficient with virtual modeling?

    I made a cardboard box to simulate where I was going to extend the kitchen counter for the other half to look at a few weeks ago. I could have done a model, but having her stand in front of the proposed new addition to the counter, see that she could still have her recycle bin under it and sufficient room to go past it, into the laundry room, was much more informative than any 3D model of the room, no matter how much accuracy I insisted it had on screen.

    We can wait for Spaceboy, but I suspect this is what he's looking for - a visual confirmation in real life, not a representation on a 19" monitor.
     
  5. TANSL
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    TANSL Senior Member

    I very much like what you say, PAR. Just say that sometimes I infer from your comments a certain contempt for the use of CAD / CAM. This is my feeling and you can not refute.
    For Spaceboy, my advice is, if he can not do yet virtual models, to immediately begins to practice with them. Meanwhile to make the 1/12 scale model or whatever scale he wants. This way he can figure out what scale is that serves to him and his boat. But, of course, to begin as soon as possible to practice with virtual models.
     
  6. SukiSolo
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    SukiSolo Senior Member

    I think the problem is a 3D one. A lot of people cannot properly think in 3D. Some problems are 2D and other parts a blend. It is a bit like all the industries that have their way of drawing. Lets take an architects 'Ceiling Plan' view, well no injection moulder would have been presented with that!. So while naval architects draw one way and aircraft boys and girls another and then theres HVAC drawings and PCB circuits etc etc. It does not take long to get your head round different drawing conventions, I probably have more trouble going from 3rd angle to 1st...:) but thats if you already know what a drawing is.

    So a 3D virtual model has great uses (a hard NURBS model) and can be rendered to give a client a very good idea of a finished product. The details inside that model may be more easily solved by the cardboard and foamcore sheet methods which because they are done 1:1 fool no one.

    The problem with the computer is you can make something a few mm thick look like it is way thicker or a space much bigger. It is our ability to conceptualise reality in our heads which is the important thing to keep it grounded. One quite good hybrid is to just get detail areas that are complex rapid prototyped and block up the straight forward bits, ie panels etc. Even on a scale model this can be useful. Might also be good to get some parts made up full size but local detail only. Similar to that ply model area Michael had done. Horses for courses, I am open to any method that is quick and gives you the information needed.

    On scale models, my gut feel is the bigger the better within reasonable limits ie it must fit in a test tank or similar. It reduces scale factor errors. Cars are usually done at 1/5th btw for preliminary aero test and styling bucks. You don't need much to make a model either, I've made quite a few from jellutong and bits of MDF, ply, ABS sheet foamcore whatever. The key is to get the information you are looking for from the model. Ask yourself, What is the purpose of the model? The answer will tell you where to focus.
     
  7. TANSL
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    TANSL Senior Member

    In my opinion this is the only real problem. People flee computer 3D model because it scares the thought of it and seeks explanations for denying the effectiveness of this tool. I do not scorn, at all, the use of scale models of wood or any other material. Everything has its own territory and, if properly used in its territory, outperforms other things.
     
  8. PAR
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    PAR Yacht Designer/Builder

    Why would a builder of a single boat need 3D modeling skills when they have plans in their hand? What purpose would this skill serve other then to redraw the work of the NA? What would be next, learn hydrodynamics and engineering too? He's building not designing, so what's the need for a modeling program?
     
  9. TANSL
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    TANSL Senior Member

    Dear friend PAR, I think you better do not go down that road because you're wrong. If you ask these questions to a medium or large shipyard, they will be astonished. Today many shipyards can not conceive, they couldn´t, build (I say build, not project) without 3D virtual models.
    You know that sometimes the constructive drawings are deduced from 3D model?.
    I believe that everything we're commenting spaceboy does not mind. If you want, start a new thread about the disadvantages of computer 3d models.
     
  10. spaceboy
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    spaceboy Junior Member

    Thanks gents for the comments. 3d virtual modelling sounds interesting but I can't even use a spreadsheet, and 3d printing is probably very expensive for a one time build. My idea is to loft and build the boat in miniature first. I chose a 1/12 scale because it would seem large enough to allow me to build all parts to a reasonable resolution, while keeping the model size manageable. At this scale it would be 57" long. I would like to build it in steel, but at this scale it may not be possible to scale all the scantlings down to that size. The main purpose is to be able to see how it all goes together and get a feel for what is involved, maybe make all the mistakes when it costs nothing.
     
  11. PAR
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    PAR Yacht Designer/Builder

    Once again TANSL, you've completely missed the point, possibly because of your experience level. Wrong, are you just this closed minded or is it a failing, that prevents you seeing what this particular project, by this particular poster has in mind. Do you have to insist that 3D modeling as the only reasonable choice. Really? To what end? What could a builder, of a single yacht gain from this? Why would any builder want to develop yet another skill that isn't going to forward the project one single step? What a narrow view of yacht building you have.

    This poster isn't a shipyard and the questions being asked are by a single person, looking to build a single project and shouldn't be continuously confused with any facility or professional, for profit organization.

    No one is talking about the disadvantages of virtual modeling, but I am saying it's absolutely nuts to consider it, if you are just building a yacht to a set of plans. Maybe you can't get through life without tapping out endlessly on a keyboard, before you know what you're doing, but many of us, amazing as it might sound actually can bend over and pick a board to cut or plate to hang. Maybe you've just never built a yacht, only played with virtual models. From this vantage point, I can understand your marriage to the machine. Maybe you've never used a tee square and a ruling pen or twiddled your thumbs, as you waited for ribs to cook in the steamer. As seemingly imposable it it might appear to your limited view of yacht building, we've been building quite fine ones, for a number of centuries now, in spite of us lesser individuals, not having used a virtual model to nurse us through the process.

    Lastly and as i correctly accessed from this poster, his skill set would need a major revision for 3D modeling, which will net very little gain in the build of a yacht, designed by someone else. 3D printing is very costly and 70' yachts are decidedly out of the question, regardless of build material.

    So tell me TANSL, why would a novice builder and computer operator, need to learn virtual modeling, to build a boat from a set of plans?
     
  12. TANSL
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    TANSL Senior Member

    Spaceboy, if you need any help, do not hesitate to ask. I offer you the opportunity to do virtual model of your boat while you do your model scale1/12. I can even make the templates for cutting the parts of your model.
     
  13. upchurchmr
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    upchurchmr Senior Member

    Finally this worked out.
    PAR provided some useful comments on 3d, what it takes, and the practical limits.
    Spaceboy decided on a path useful for him.
    Tansl offered help with his particular talents.

    A nice finishing place so far.

    And, we don't have to listen to two people talking past each other. Notice I had no comment on who is right-er!
     
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  14. El_Guero

    El_Guero Previous Member

    60'?

    You might be best served in taking TANSL up on his offer, work through the 3D, and then build your physical model.

    You might want a second larger model before you build a sixty footer - sixty foot will be real money.
     

  15. SukiSolo
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    SukiSolo Senior Member

    I think Spaceboy, if you can live with it a 1:10 scale would be even better. So simple to scale you can do it on the fly. Build the hull upside down so it can be faired correctly, you can even work out the plating if you use mylar film or v thin ABS sheet.

    Personally I'd use 6mm MDF sections offset for 2 or 3mm marine or aircraft ply or even thin WR cedar strip planked. At 1:10 this will be around 1800mm long, plenty big enough to get good accuracy. You should also be able to get it correctly faired and sealed so it can be floated. Make sure there are enough braces when you turn over and then pop in the internal stuff, which can be temporary or not. Now you will have a true appreciation of all of the vessel.

    Good luck, I'd like to see some shots of the model.
     
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