I am deeply sorry for not replying earlier. It's been a long time, I have been busy and studying on another country, so not much time to devote to this. As I don't expect to work on my submarines until this summer, here are some pictures of what I did. Everything was printed in segments, in white abs. Then it was "acetone welded", painted with abs+acetone mix and then sanded. Hull thinkness is 2 mm and the model is about 50 cm long. Upper and lower hull are held together by magnets.
Hull, after assembly and sanding.
Hull inside and linkages. I used brass rods, paperclips (which do oxidize) and screw terminals. Not the best, but it worked. It was a pain to cram all that in the tiny aft cone. I'll see if I can take a photo of the inside linkages.
Rear view with an unfinished propeller. I printed them with the blades flat, then bent them with some pliers and then submerged them into abs+acetone to reinforce them. They were not that strong, but they worked fine. I made about five and I went trough three of them.
Here you can see the WTC made out of a silicone tube, Endcaps were 3d printed, and a silicone gasket was used. Two screws pressed the endcaps in place. It was not reliable and often leaked. That's why I left it on hold, I'll have to make a proper WTC, and that would mean redoing everything but the hull, because it's not modular. Part of the rear magnetic copling can also be seen.
This is the rotor that drives the magnetic coupling that in turn drives the propeller. It is connected to the motor by a gear, which is also 3d printed.
This is the inside of the WTC. Motor is on the bottom, so are the batteries. I first had a servo push some switches to drive the motor, later on added an ESC.
And here it is, in the water, it was weighted so just the sail (which was hollow) was above water. It could dive dinamically using the rear planes.
Radio reception wasn't the best as I folded the antenna inside the compartment. This wasn't designed for great depths though.
I even had planned adding an air pump and solenoid valve to make it statically dive with a rubber bag...That's not going to happen. If I ever get it properly working, it'll remain dinamic only.
I maybe make a new wtc with a nice cilindrical container that I found, which has a threaded cap...Who knows...
So there it is. I hope someone finds this interesting and can get something out of it. I'll remember to check the forum more often. Any questions/suggestions are welcome.