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Modeling a wooden boat

Modeling a wooden boat

Modeling a wooden boat

(OP)
I'm using sw2004 to design a wooden boat. My approach has been to make a solid of the boat then use that solid as the basis for each of the major parts by cutting away material. Using this approach I hoped to have all the parts fit perfectly without having to figure out all the geometry.

For example, the outer shell could be created by cutting the solid in half and shelling. Then the frame and mold componants can be built by extruding up to the shell surface.

Sounds easy, but I can't seem to get past the first step of creating the solid hull. I've tried numerous approaches to get the shape that I'm envisioning. I can get close but there is always some small flaw that I can't seem to eliminate.

Has anyone else had any experiance in designing boat hulls in solid works? -or- Is there any technique for getting rid of small flaws in solids with compound curved surfaces?

RE: Modeling a wooden boat

SW has serious shortcomings with respect to curvature control on splines and surfaces.  This may be the source of your flaws.

Here's an experiment you can try to illustrate:
PART I:
1.) In a new 2D sketch, draw a spline with 4 or more points that are not in a line.
2.) Right-click the spline and select "Show Curvature".

Notice that the curvature at each end is forced to zero.  Zero curvature = instantaneously linear.  This is a problem if you are trying to match curvatures between surfaces.

PART II:
1.) Sketch a line that crosses the spline near the end
2.) Trim the spline using the sketch trim tool to remove the end of the spline up to the line, then delete the line.

Notice the spline curvature at the cut end is no longer forced to zero.

SW does not have the means to explicitly control the curvature of a spline at any point.  SW also does not allow matching curvature of surfaces at loft or sweep edges.

Due to illness, the part of The Tick will be played by... The Tick.
http://www.EsoxRepublic.com

RE: Modeling a wooden boat

Have you tried sweep with paths and guide curves? One at top to show boat outline and one at each side and end to show curvature.

RE: Modeling a wooden boat

(OP)
Thanks, Scott I'll check out the site.
Boy Tick, you sure are right! I spent alot of time on this. Not only are splines hard to work with, but also partial elipses and parabolas as well as intersection curves. It seems the best thing to do is try to create the feature with excess, then cut away the excess. It will take alot more thinking and construction geometry but I am going to try it and see if it works.
Thanks for your comments.

RE: Modeling a wooden boat

I think that using lofting to create your boat shell is the direction you should be going.  

I would recommend the demo / training exercise in the SolidWorks manuals that have you creating a dish soap bottle (think of the bottle of Dawn or Ivory dish soap in the kitchen.)  I don't have it right off hand, but if you can track it down I think it will give you the fundamentals for the sort of curved surface you are looking for.

As a first generation, simply follow the exercise, lay the bottle on its side and slice off the top half - instant first prototype.  Doesn't give you what you wanted, but gets you pointed in the right direction.

RE: Modeling a wooden boat

Check out AeroHydro's SurfaceWorks. They are a Solutions Partner. If you are interested in marine design check them out.
http://www.surfaceworks.com/


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