Lego Submarine

This is a submarine I made from a plastic box. I used lego power functions with a lego motor and servo. This instructable just gives rules of thumbs to keep in mind while making it and feel free to be creative. I This made after getting inspired by a youtube video.

I had 1 lego IR remote control along with two motors and 1 servo motor. ideally i would suggest you to have 2 servo motors but you can also make do with one.

First you will need to take a box which will be you submarine's hull. I chose a plastic box for this.

The blue squares are the motors. They are designed to turn and accelerate our submarine. The Two yellow squares are diving fins. These fins can be fixed or moving. I only had 1 fin but the submarine could dive albeit more slowly.

I made 3 small holes on the box. I fit the shaft inside and used a plastic straw to connect it to the propellor. I also added putty where the shaft connected with the hull. The putty stops the water from entering however dont be alarmed if you find drops of water inside the submarine. I tested this model underwater to check for leaks. I found that air leaked from the lid so i suggest adding an o-ring to seal the lid.

After that we can add the lego motors and the servo motor. I used lego base plates to hold them together. The diving fin should also be angled to give a good angle of attack for the div. As an alternate you can also have the dive plate fixed at a certain angle.

After completeing these steps make sure to check if the weight distribution is equal so that the submarine isn't lopsided in the water. I used lego bricks and repositioned my battery to equal the weight distribution due to my asymmetrical design.