struggling!!

[snow 57]

Hi Guy's
I have been doing the rhino tutorials for some time now and have just started to draw my first boat design. I'm not sure how to go about it, and have tried to draw the stations then "loft" them, but I'm not getting the fairing to happen the way I thought it would.
Can anyone give me a few clues on how best to do this. Hopefully I just need pointing in the right direction.
cheers Snow

[Gilbert]

Straight from the horse's mouth (but second hand via this note); I attended a meeting where the company was demonstrating Rhino and they said Rhino is really intended to import a hull shape and refine it. That is unless they have dramatically changed things in the last couple years. So that is usually the approach people take with it. I am not saying you can't do the whole thing in Rhino, just that it's probably going to be easier importing something to start with. Someone correct me if I am wrong with regard to the latest versions.

[snow 57]

Thanks Gil,
I have background images I'm trying to start with,
plan, profile and elevation. I've been playing with it for a while now with limited results. Just can't get to grips with the program and am investigating more tutorials.
Snow

[Raggi_Thor]

Do a loose loft with rather few stations, then refine the shape by nudging the control points. Use as few control points as you can. Then section the hull to see if it match you original curves.

[Michael Chudy]

We do all our hull design right in Rhino, and find it very flexible and easy to fair - getting just the shape we want. Often we use curve network for surfaces. Have you looked into a Marine Rhino Design class such as that offered by YDS?
Michael

[nautical]

hi Snow 57

Same opinion as Raggi Thor.

http://www.3drender.com/rhino/boathtml/index.htm (hope this helps you some more)

good luck

[tananaBrian]

How to go about designing a hull depends on whether you are designing a boat that requires developable panels (plywood, aluminum, steel) or one that does not (cold-molding, fiberglass lay-ups, etc). The process of developing a hull without using developable panels is far more challenging and requires more experience. The Rhino tutorials tend to be out of date as well ...designed for v2.x rather than v3 or v4 and nobody's updated them. I'm referring to the marine design tutorial anyway.

I for one don't have much interest in non-developable hulls since I'm not interested in the construction techniques that they a require. I'm far more interested in ease and quickness of building and reduced cost instead. Someone else is probably a better guide for hulls of this sort.

For developable hulls however, I'm pretty good at getting the job done and have a work flow that works well:

- I generally draw my boats on paper with ship's curves and what not first, working out aesthetics and basic hull forms. Then I measure offsets off the drawings (3-view).
- Using these offsets, I draw my curves in Rhino in plan and profile right on the construction plane using InterpCrv. Then I rebuild the curves so that they are 2nd or 3rd degree (using degree-plus-one control points) since conics develop better.
- I fair these curves using the curvature analysis tools
- I use Crv2View on the plan and profile curves to create the 3D curves (chines and sheer).
- Finally, I use Loft (with Developable required) to loft the panels, making sure to pick the starting points towards one end. If Loft fails, then I sweep a straight line along the two curves in order to create a panel ...if the V lines are spaced nicely and don't appear to be too close, you'll find that the panel is developable.
- I join all panels and use naked edge analysis to look for poor fits
- I continue the model (CG analysis using real designed components and boat contents) until I am ready to plug it into RhinoMarine and evaluate the Hydrostatics.
- Iterate the whole process until the boat meets all criteria
- Perform a RhinoMarine hydrodynamics analysis, iterate more if need be.
- When all is well, perform detailed design and validate your CG analysis ...if it's off, then it's back to the drawing board ..the whole enchilada.
- When all is REALLY well, then unroll the panels and complete the design and build documents.

Have fun,
Brian