Re: How to set up for a hull loft

DELFTship forum Hull modeling How to set up for a hull loft Re: How to set up for a hull loft

#34439
otaku
Participant

2010-11-24 my drawing advice to proflooney.txt

Hi Proflooney (Prof Looney?)

First off, welcome to DELFTship. I’m just a regular user, so I will speak only on a few things and only from my own experience.

I would imagine these steps:

1. Open and play around with COPIES of the sample drawings provided. Look in DriveLetter:ProgramsDelftshipSamples (I think it’s Samples; save the copies to your user directory so you don’t ruin the originals by mistake)

2. Turn on the mesh and other layer features and move the points/nodes around and observe what happens to the surfaces. Look at the surfaces in each view mode.

3. Practice deleting by delete key and removal by the applications’ collapse tools. Notice the effects each has when surfaces, edges, and points are removed.

4. Once comfortable with the level of detail of each model, choose one and practice scaling and transformation of them. One may be a great starting point for stretching and a good basis for your declassified drawing’s start point.

5. Carefully remove from the sample drawing the various edge/boundary lines you don’t need, noting that some of the superstructure present may be useful. If in your way or making for visual clutter, find and turn off the relevant layer. Change the layer colors if it suits your eye to do so.

IN THE MODEL YOU ARE DRAWING

1. Configure your preferences/drawing units, and other settings

2. Import the declas’d drawing to a suitably-named layer, starting out with the profile view, so you can get the hull length and sheer/camber, etc very close so you can mentally know where you are at any given time.

3. Make sure your scale and units in the model view match the paper dimensions.

4. Import the bow and stern (bodyplan) views onto each their own layer so you can declutter your view as necessary.

5. Again play around with the bodyplan view button to realize what is happening when you show only the half-breadth vs the full body plan.

6. Import your plan view (top-down) onto its own layer, too.

Adjust points as necessary, and add some as necessary. Some abide by the principle that the fewer points, the better the fairing. But, for certain cases, i definitely add more points so i can force forefoot (bow/sonar shapes at the bow), flare (outward curvature of the bow area plating), and cut-up (angle of the stern from near the propeller shaft exit from the hull out up to the rudder/transom area).

Note: Some would start out fresh rather than transform and strip a model. But, it’s a matter of preference, time constraints, patience, and more. DELFTship is most decidedly not a CAD progam in that you cannot draw a deck one by one and then expect to join them magically with the program able to deduce the curves for purposes of hydros generation.

However, there is ONE possible cheat:

Trace the ship in your favorite CAD package. Assigne decks to a suitably-named layer. Same with bulkheads. Sam with sideshell. Same with propeller shafts and silhouettes of your engine blocks or other major equipment.

Set deck thicknesses for bulkhead, casings, hatch coamings, and more and do your best to have proper intersections of lines, avoiding unnecessary overlap or excess surface/solid matter.

If your program allows, export it as IGES and import those surfaces (and resulting solids) into DELFTSHIP, if you have DS Pro.

If you have gotten this far, then inspect the Layers interface to observe the inclusion of your objects and their layer names. If you export it as an IGES file again, it may be all green. But, you should have a great basis or parent model that you can fair and run reports on, although the blueprints/lines plans you have were created by experienced designers/drafters, meaning a LOT of guesswork or research on your part will be avoided or minimized.

Others may wish to join in as the have MUCH more experience than i do.