Code for the big boat has been taking up most of my time, but in the mean time I've still been working on the sails for the little boat.
The original sail design didn't work -- I couldn't get enough weight on to balance it against the overly long lever arm. The airfoil shape is also not great, because my first shot at hot wire cutting and using heat shrink film didn't turn out so well.
As a result, we're working on some new wings. One of the ideas I am pursuing for them is 3D printing in ABS. To that end, I've acquired a 3D printer (one of the $300 Monoprice ones, if you're curious) to help with building the next set of test sails for the little boat. The printer has largely worked very well, especially for the price, but the delamination was awful. I solved that with a quick box made of pink styrofoam panels and hot glue. It's neither pretty nor clever, but it works. It's just five 2'x2'x1" project panels hot glued together.
Putting the printer on the concrete floor rather than the rickety table helped as well. Here's some of my test prints:
The dog-bone was printed inside a box and then finished with cold acetone vapor, which works amazingly well. The black coating is black ABS dissolved in acetone and painted on. It works, but it's heavy. This was part of my original thought, which was to 3D print everything except a spar to hold the whole thing together. I don't think this is the right way to go, because it will take approximately forever and a day to print the whole damn thing.
Luckily, Autodesk just ported Slicer over to Fusion 360, which makes it simple to turn a solid body into a grid of laser cut pieces. I can then skin that with either very thin plywood or heat shrink film. I will probably go with the plywood, because I think I can apply that with a thin film of glue and heat shrink tape acting as a poor man's vacuum bag.