Anyone who knows me knows that I totally dig submarines and sub movies. Whether it's a great one like Crimson Tide or a total pooch like Down Periscope, I gotta watch it. Submarines are the ultimate toy and the closest thing to real spaceships we're likely to see for a long time. When I first stumbled across the OpenROV project, I was hooked at once
Obviously an ROV isn't the same as a submarine, but it offers many of the same benefits and even a few advantages -- like the ability to actually see while remaining well above crush depth. In the past, ROVs have been expensive so the design and testing cycle is long and they're reserved for high-value missions.
The OpenROV project is very young and they're still getting their legs under them but it has some really cool things going for it. It's designed to be inexpensive, flexible, and require few specialized tools. The physical structure is almost all laser-cut acrylic. The bottom side electronics are meant to be open hardware like a Beagle board or Raspberry Pi. That means the ROV can be cheap enough that innovations and improvements can be tried out quickly even if they risk the ROV. It doesn't have anywhere near the depth capability of a 'real' ROV but at theoretical depth of 100 meters it could reach most of the continental shelf. That's a lot of room to play. My goals are a bit more conservative. A 5 acre pond in my Missouri back yard that I'm certain is, like McElligot's Pool, connected to the deep ocean. There's no telling what I'll find down there.
OpenROV recently started a Github repo to host hardware design files and software. They seem to be working in Autodesk Inventor which is, unfortunately, a closed format. A friend converted the files to both STEP and IGES for me and I was easily able to import them into FreeCAD. From there I was able to assemble it in the computer to produce this:
I've forked the OpenROV repo and added my converted files and FreeCAD file. FreeCAD doesn't support any bending of solids which is necessary to model the outside shell. The friend who converted the files made both a folded and unfolded version of the shell for me.