CDR_Ret

Larry, I stand corrected on the 'Bama. That would make a more interesting (and challenging) model to work on. If you are going to model directly on a drawing, you still need a spreadsheet or table with offset-like (x, y, z) intersections to enter into the control net point editor. Otherwise, you will end up with a 2D model. My suggested sequence to start this project DELFTShip would be the following, though this isn't the only way to proceed. Create separate profile, plan, and body view JPG files, all at the same scale. You will need a photo editor to do this. Make them as high resolution as you can (300+ dpi). Create a new project in DELFTShip. I don't have the program in front of me right now, but I think you just click on the white blank page icon in the upper left corner. Follow the instructions and save it. The 7.X version of the program has a Windows-like ribbon. Under the Home tab, click on the Project Settings button. Fill in the General stuff as desired. The really important thing to get right at the beginning is the type of units used. Select either metric or imperial (English), according to your plans. If you forget to do this and leave it in metric (default), when you go back and try to switch to English, it does a dimensional conversion, not numerical. In other words, if you create a model 150 feet long in the meters setting, and then realize you want it to be in feet, and switch the units here in the Settings dialog, the model is now 3.281 ft/m X 150 m, or 492 feet long! All is not lost though. Just use the Scaling feature on the Tools tab and scale length, width, and height by 1/3.281, or 0.3047. Still in the Settings dialog, click on the Main Particulars tab and fill in the Length or LBP (distance between aft face of stern post at LWL to intersection of stem rabbet at LWL), Beam (maximum moulded width), and LWL Draft to baseline. Galilee's baseline was the keel rabbet line. You will need to determine your plan's waterline baseline for this data. The Mid-ship location is set by default at 50% of Length, but if you have a station at that point, I would select a position between stations. This item determines at what point the program splits the stations between the front and stern halves of the body plan view. It should correspond to your body plan image you will be using. You also need to select the Longitudinal reference point. It defaults to the midpoint, but many plans use either the AP or the FP for reference. Galilee's plan used its vertical stern post for the reference. (I recommend the AP because all x values will be positive forward of this point.) The rest of the settings are of little interest to the modeler (IMHO). I can't recall exactly, but I think there is a default model in the new project window. Just select all and delete the model. The next step would be to add the three images in their appropriate views. This is done under the Tools tab. The process is addressed under Section 3.4 of the manual, but it's pretty vague as to the order of operations to make the process reliable and straightforward. I need to be looking at the program to explain this, so it will have to wait. For Bruce, I think it was more the fact that I held an eagle feather in my left hand, and shook the rattles twice before clicking Accept that made the images go where they were supposed to. Some general hints on hull modeling from scratch: Building a model using a Control Net is not the same thing as drawing an image in 2D. You are creating a subsurface framework that influences the shape of the underlying surface but is NOT part of the surface except at its edges and at "creases". Read Section 3.1 for a (very) brief overview of this modeling method. If you have used Blender or other subsurface modeling programs, then this should be old hat. To create a surface, you need to first have at a minimum of 3 control points in different locations (see below).Then you have to select all the points that will be used to shape that surface. This is done by holding the Ctrl key down and selecting all the points one at a time (more control) or by band-boxing (less control). Then press the Add Face button (the manual's button doesn't agree with the program's here because the GUI was updated since the manual was published). Connect the control points with control lines as desired. This is done by selecting two or more points as above, then clicking on the Insert Line button. For more control, I usually do this with pairs of points, though you can generally do a string of them as long as they don't form an obvious polygon. Otherwise, you may have lines connecting all the points to each other. When you use the Add Point button on the Ribbon, it places the new point at the 0, 0, 0 location and displays the Point editor. To obtain a precise location, as with offset table coordinates, fill in the x, y, and z values in the point editor box. Note that x is positive forward of the longitudinal reference (a good reason to make it the AP), y is positive from centerline outboard, and z is positive from the baseline up. All coordinates are negative on the opposite sides of their respective reference lines. One last thing about selections. In the newest version of the program, clicking on control points with just the mouse deselects the previous point selected (selected points are highlighted yellow). Not so control lines and surface patches. Sequentially selecting lines and patches keeps all selected until you press Escape. I think there is a Deselect All button in the ribbon with the newest version, but I haven't checked that out. This bug can get you if you are trying to select edges to make them creases, such as along the edges of the keel or stern post. You end up toggling one edge to uncrease as you try to crease another if you don't unselect it first. Very annoying. I just noticed that the DELFTShip Free webpage doesn't have their latest manual available for download. You will need to send an email to Maarten Visser (maarten@delftship.net) at their site and request the latest (it should be "manual_714_282.pdf" or later and it's nearly 10 MB). If it's a later version, please let me know. Got to get back to work, but if you desire, I can elaborate on some of the other basic processes and features sometime later. Terry

Not to disagree with Bruce, but you can import separate images into all three standard views (see the attached image of Galilee when I was working on her stern). Not that it's easy to do so, and if you don't hold your mouth right, you can end up with all three images in one view! As Bruce said, you can import the model as a table of offsets. The manual describes how to do that, but it leaves out several gotchas and the terms they use for the different rows and columns in the text file are ambiguous. I would recommend starting your model this way if you have a CAD program that can display x and y coordinates for station and waterline intersections. If you try importing these into the program, it's going to look pretty messy until you create and designate the crease lines (edges where the curve of the surface is discontinuous). Considering you are doing an ironclad, I assume there will be a lot of those.

Larry, I can help get you started. I'm still tweaking the final hull form of Galilee, but it's the getting started that is tough with this program. I would recommend downloading the free version of the DELFTShip program and manual from here. Be sure your system meets the OpenGL requirements. Read through the interface and hull modeling sections, and then I can walk you through setting up a file, inserting the plan images, and then building up the hull. It's not intuitive by any means, but once everything is in place, the actually modeling is pretty straight forward, and produces a cool result. PM me if you want to do this via email. Terry

Chris, yes, the program is actually quite useful in that respect. You just set up the station spacing on the baseline to match the room and space (14 inches and 14 inches) of the original hull, and the forward and after moulded frame edges appear on the plans. The program projects the stations onto the modeled hull surface. They aren't fixed reference points that determine the hull shape or anything like that. I have a fairly accurate idea of the framing from direct measurements on the bow at the Benicia museum and the stern at Fort Mason in SF. Interestingly, Matt Turner didn't use cant frames, so the spacing problem is even easier to deal with. Druxey, by "fidelity" I meant "true to form", not necessarily structural accuracy. I'm not sure how many bulkheads you would need to avoid the inevitable flat spots between them if they are too far apart. I've carved a half-hull of Herreshoff's Gloriana using the lift method from WoodenBoat plans, so I'm comfortable with that. I could carve the moulded shape of the hull then plank on top of that. The result would be a pretty heavy model, though. Terry Greenville, South Carolina, USA

I am approaching the point that I will need to make a decision as to what technique I will use to build the hull: plank on frame, plank on bulkhead, or the lift method. My model is a fairly straight forward late 19th century brigantine merchant. Never having built a hull from scratch, I am willing to attempt any of these methods, but my greatest concern is ensuring the fidelity of the finished product. Anyone here have recommendations (preferably with explanations)? Thanks

Good morning lehmann. Nice work with that CAD model! I've been using DELFTship Free for developing a set of plans for my brigantine Galilee project, which is featured elsewhere on this site. I must be dense, but the program was anything but intuitive to start a project in. The manual is only marginally helpful. After a steep learning curve, I'm approaching the point where I believe I have a reasonable hull. My reason for using the program arises from the need to correct the stern/transom shape of the vessel in the Smithsonian plans, which are the only existing complete set of drawings for the ship. I have a number of contemporary photos of the vessel that show a distinctively different shape. Chasing these kinds of adjustments around three 2D views is a frustrating task, while the consequences of making adjustments are immediately visible in a 3D CAD program. I'd like to see more modeler interest using this program. It has a lot of potential for identifying errors in plans before committing time and wood to the build. Terry