Dr PR

I have been building ship models since I was a kid (about 65 years). I started with plastic models and then began building scratch built models out of balsa. In my 20s (when I could afford it) I graduated to wooden ship model kits. I was fascinated with ships and joined the US Navy, entering Officer Candidate School in 1968. I "retired" as a Lieutenant in 1972. I served on three ships, two minesweepers (USS Cape MSI-2 and USS Ruff MSCO-54) and a cruiser (USS Oklahoma City CLG-5), all having wooden decks. I wanted to model two of these ships, but there are no kits made for them, so scratch building is the only resort. I did nothing for years until Christmas of 2004 when my oldest son presented me with a 8" x 8" x 72" present. "They are giving me new skis?" I wondered. No, it was a 6 1/2 foot long fiberglass hull for a Cleveland class cruiser. The USS Oklahoma City CLG-5 was a converted Cleveland class ship. That started a 14 year odyssey (so far) to research, design and build a 1: 96 scale model. This evolved into a CAD model to create plans for the real model and an extensive web page for the ship, with the ship's history and a history of the modeling progress (https://www.okieboat.com/). I have been posting on The Ship Modeling Forum (http://www.shipmodels.info/mws_forum/index.php) in the Virtual Shop Modeling section (http://www.shipmodels.info/mws_forum/viewtopic.php?f=27&t=70810) for years. I have just discovered this forum. I am a former NRG member, and I am considering restarting my membership now that the Ships in Scale magazine has been acquired by NRG. Phil Hays

Wayne, Right now the model is in four files. I pasted renderings of the four files into one image in Photoshop. I have yet to combine all four - in fact I may not be able to in DesignCAD 3D Max. The largest file I have worked with was about 750 megabytes, but that was several versions back. I do not know if the new version can handle a gigabyte file, although it is 64 bit and should be able to handle it. I will take on that challenge this winter when I can't get out hiking. The four files add up to 1.071 gigabytes. There are a few duplicated reference parts in each file, but after they are removed the total file size will still be about a gigabyte. There are 2.86 million DesignCAD "entities" in the files, but I really don't know what that means in terms of objects drawn in the files. A single object like a cylinder may be composed of many "entities." But I do know that there are a LOT of objects in the files! There are 22 million points in the files. Hull: 220,258 KB Forward superstructure: 312,148 KB Midships superstructure: 234,964 KB Aft superstructure: 303,890 KB Initial render times for each of the four files varies from about 40 minutes to 95 minutes (all surface normals and shadows are calculated during the first rendering). After that new renderings take up to two minutes. Render times are not linear with file size, because the program has to check for shadows on each object that might be cast be all other objects. I expect the initial render time for a gigabyte file will be 4-5 hours. I'll start it before going to bed and it will be ready for subsequent renders the next morning. Note: After the initial render and when working in OpenGL display modes, rendered displays rotate quickly. However, if the file size is several hundred megabytes and all layers are enabled (everything visible), display rotations get a bit "jerky" - slow. **** My work station was built in 2013 and is five years old now. It was designed specifically for 3D CAD work: Windows 7 Professional 64 bit Intel i7-3930K 64 bit processor, 3.2 GHz, six cores, 12 processes (DesignCAD can use 11 processes, Windows typically uses 1) Intel DX79SR motherboard, 64 bit data bus Liquid cooler for the processor * Chassis has 10 fans to keep everything cool 32 Gbytes 64 bit DDR3-16 RAM - Corsair CMZ16GX3MAXx1600C ** Nvidia Quadro 2000 video card. 192 Graphic cores, 1 Gbyte DDR5 RAM. Drivers optimized for hardware support for OpenGL. *** Dual Display Port monitors, 27" and 24" Four hard drives: C 1TB, D 1 TB, E 1TB, F 3 TB. Drive D is used for the CAD model. **** I use a Kensington Expert Mouse trackball. * The Intel i5s and i7s have built in over temperature protection. This is provided by an extra CPU embedded in the chip that just monitors the hardware. If any core exceeds 65C the processor clock will be stopped until it cools below 65C, and then restarted. If this doesn't work the CPU voltage is reduced (this may cause instruction execution errors), and if that doesn't work the CPU shuts down. System performance plummets when the CPU clock is interrupted like this. If you want to run full speed under all circumstances (without processor clock interruption) you have to get rid of the heat in the processor. Air cooled heat sinks are only marginally effective. The liquid cooler has worked so far, and the machine runs without clock interruption even in the most demanding operations that run all six cores at 100% duty cycle for long periods. I can tell when the thing starts to heat up. The ten fans normally run with only a slight hum. But when I start working with large numbers of objects in DesignCAD, or rendering large files, or working with very large images in Photoshop, I notice the fans speeding up. If the room temperature is high (>85F) the fans can rev up so it sounds like the thing will lift off! Laptops do not have sufficient cooling, so i5s and i7s often operate with interrupted clocks. You may have a "3 GHz" CPU, but it may operate at a much lower effective clock speed if it is doing serious work. But at least it won't fry itself as some other processors were prone to do. The Intel motherboard came with a hardware monitor program. It allows monitoring temperatures, voltages, fan speeds, etc. My system normally runs with a CPU temperature of 32C with a room temperature around 25C (77F). I have never seen it go over about 42C. The i7 K series CPUs were designed for overclocking, and I have read of i7-3930s that are clocked at 4 GHz. I have not overclocked this CPU. It gets hot enough without overclocking! ** The fast RAM is the key. In 2013 this Corsair RAM was the only thing on the market that would actually run with a bus speed of 1.6 GHz at a bus voltage of 1.5 Volts (the i7 nominal bus voltage). Most other RAM makers claimed 1.6 GHz speed, but the RAM had to be run at greater than 1.5 Volts. Go over 1.6 volts and the CPU is fried, as has been discovered by many unfortunate people who did not do their homework. I enabled the XMP memory feature in the motherboard BIOS. This allows the CPU and RAM to work at the fastest possible speed (1.6 GHz) at 1.5 Volts. Without XMP enabled the RAM would have worked at 1.33 GHz. However, with other manufacturer's RAM and XMP enabled the memory bus voltage might be raised above 1.6 Volts and fry the CPU. You need to do your homework on this one! If in doubt, don't enable XMP! The RAM is quad interleaved on the Intel mother board to wring out the fastest performance. *** I work mostly in OpenGL in DesignCAD. The Nvidia drivers enable video card hardware execution of OpenGL operations. This is MUCH faster that total software execution of OpenGL code. Most other manufacturer's video drivers do not support hardware acceleration for OpenGL, it they support OpenGL at all. They are optimized for video games that don't use OpenGL. **** Hard drive seek operations are the slowest operations in the computer. Placing data files on a drive different from the drive where the operating system and program are located allows faster operation. Both Windows and DesignCAD use virtual memory paging to swap out code and data between RAM and the hard drives. With Windows and DesignCAD on Drive C and DesignCAD data files on Drive D, the code swapping seek operations on C can proceed while data seeks are in progress on Drive D. Phil

Hi, I'm a newbie to this forum, but not to CAD or CAD ship modeling. I have been using DesignCAD 3D MAX since 1988 in my work, and also for ship modeling. The program has three significant advantages over every other CAD program (about a dozen) that I have used. First, it is cheap - about $100 US. Second, it has the best and most versatile user interface of any program I have ever seen - five ways to execute commands, including a macro language, so you can work in the way most comfortable for you. And best of all, it has free technical support and a very active user forum (http://forum.designcadcommunity.com/). I have been working on a CAD model of the USS Oklahoma City CLG-5 in the summer 1971 configuration for fourteen years. It is just about complete. Most of the 14 years was spent researching blueprints, drawings, data sheets, etc., and collecting over 1000 photos of the ship. You can see images of this model here: https://www.okieboat.com/CAD model.html The entire model was done in DesignCAD, so if you want to see the capabilities of the program for ship modeling have a look at my web site. If you are new to CAD I cannot overstate the importance of an active users forum for the program. Many very experienced users from all over the planet follow the DesignCAD forum and are happy to answer questions from new users. DC tech support also watches the forum and answers questions. As others have said, learning CAD programs can be difficult for the first time user. You not only have to learn how to get the program to do what you want to do, but you also have to learn to think in a virtual reality. Forget any limits you have learned with 2D drawing on paper - the sheet is infinite. And if you work in 3D you have to learn to think in 3D - you are creating a new virtual world. It will take some time to become comfortable with this process. It is best to model in 1:1 scale - the actual dimensions of the ship. That way you can use the dimensions on blueprints directly without calculations and possible scaling errors. Later you can scale the drawing to any smaller scale. You can create 2D drawings from the 3D model, or you can produce 3D stereolith files (3D printing), or use your model to drive CNC machines (this is tricky). But the best thing about CAD modeling is that you can (and will) make mistakes, and later go back and fix them without wasting any materials. Phil