Part n. 1 (printing all pieces)
All stl files are printed in PLA with two shells at 0.26mm layer height, for some of tham suopport materials are needed .
The boat is printed with two shells in the spiralize way to increase the weight that can be loaded.
The body is printed at 10% infill, while the head is printed at 15% infill and fins are printed at 40% infill.
In order to do not let the water to get into the fish, some holes have been filled with hot glue.
Part n. 2 (assembling the printed pieces)
Take the caudal fin and place three thin nylon cables (about 1 m each) in the three holes. Then, there will be three cables on each side of the caudal fin. They are used to make all tail to bend right and left.
Each set of three cables will then passed into the other four pieces of the fish body.
Place, in those pieces where a pass-through hole is present, one small piece of lead at the bottom part.
Place a 6 mm tube at the center of all the pieces in order to make the pieces to stay in place.
Each piece of the fish body stays separated (about 6 mm distance) from the adiacent ones by mean of small metal springs. The springs have to be placed in the grooves that are present on each piece.
I have used the electronics and the motor of a rc-car. In the bigger piece of the fish body two big grooves are present. They allocate the battery and the electronic board. The antenna (connected to the board) has to go out of the piece through the proper hole.
Take the piece that join the tail and the head (testa_parte_3_3.stl).
The end part of the 6 mm tube has to be connected to it in order to block the tube.
Take the two pieces of the head. In the bottom part (testa_parte_2_3.stl) the servomotor has to be placed. I used some glue in order to take it in position.
Two small metal bars are connected to the servo motor. The bars are long enough to exit the head (from the holes that are present in the stl file) and are then connected to the two lateral fins.
The six nylon thin cables have to be twisted and then firmly blocked to the piece. Use the two grooves that are present in the stl file.
Take the gear and connect it to the axes of the servomotor. Place a 5 mm screw in the external hole of the gear.
Use three screws to join the two pieces of the head.
The two pieces of the head have to be connected to the piece that join the tail and the head by means of a metal ball bearing and two 4 mm passing through screws.
Take the two head covers (I uploaded the right piece only. To have the left one make the mirror of the first one) and place on the fish head. Use four screws to join the two part firmly.
Take the later fins and join them to the head covers by means of two 2 mm screws.
Connect the metal bars of the servo motor to the lateral fins using hot glue.
Take the dorsal fin and connect it to the head covers using hot glue.
Finally, take the external cover (cover_corpo_flessibile.stl) and join it to the fish body by a bit of hot glue. These two parts have to be printed using flexible filament.
I apologize because some photos do not match the file stl loaded because I did not have time to print out the improved version of a few parts.