We have two different designs of torpedoes printed out, both 6″ long, one that will fit in a 1″ copper tube and the other in a 3/4″ tube. They both fly through the water very well. We can’t wait till we put some pneumatic oomph behind them with the system that was just donated to us by Clippard Minimatic.
The marker dropper will have a pneumatic piston installed in it that will move the tray back and forth to allow the steel ball to fall through.
Below are some images of the models and what was printed out. The torpedo diameter was only .007″ larger then what we designed for, showing the extreme accuracy that 3D printing can bring.