Download wiring instructions here. 
 
This is a very compact timer switch that allows for repeated use of a battery-powered torpedo in your remote controlled submarine. By connecting or disconnecting two wires, the builder can select run times of either 3 or 5 seconds, ensuring that your weapon doesn’t run away from you in a large pond or pool.
 
In order to set up a scale torpedo using these timers, you will need to source a 3V LiPo battery, a magnet and a normally open magnetic reed switch. These parts are not (yet) available from the Nautilus Drydocks, but will be available in the future.
 
To fire the weapon, simply move the magnet away from the reed switch. The timer activates the motor for the (3 or 5 second) run time, then shuts the motor down. Retrieve your weapon, pop it back in the tube, and you're good to go once again!
 
I have a video on how I created my electric torpedos that you can view here.