This will show you how to build a robot boat from cheap and easy to use materials, I think it is also a good example of reusing water bottles.

I used two water bottles, polymorph plastic, two motors and propellers, tape, a box, a battery and a motoruino (Arduino clone designed to work with motors, servos and sensors).
Remove these adsRemove these ads by Signing Up

Step 1: Materials needed:

  • Two water bottles
  • Two simple dc motors
  • Two propellers
  • Isolating tape 
  • Box
  • Motoruino (or any other microcontroller and a h-bridge)
  • Battery

Step 2: Add the motor and the propeller to each bottle

Picture of Add the motor and the propeller to each bottle
  1. Take out the bottle cap and insert the motor on its mouth (you can use some insulating tape if you see that there is space between the motor and the plastic).
  2. Use polymorph to seal the bottle. If this is the first time you're using this material you may find these tutorials helpful:
  3. Attach the propeller

Step 4: Make the electrical connections

Picture of Make the electrical connections
If you use a motoruino, you just have to connect the battery and motors' wires to the board. If you use a normal arduino you will have to use a shield or mount the h-bridge on a breadboard.

I used a SFR05 sonar, if you use it too, check this example: Ultrasonic Ranger
karti6 months ago

hi, are you aware that the props need to be at an angle to run and not straight.

nice idea though

i cant get it .

can you plz tell me how you instal sonar on motoruino.

plz to increase the speed of the robot?

is it depend on microcontroller ?
XicoMBD (author)  altaf hussain2 years ago
It depends on your motors and on the voltage you give them.
XicoMBD (author)  altaf hussain2 years ago
where do you connect on the motoruino.

i mean to which pin

circuit plz.....
XicoMBD (author)  altaf hussain2 years ago
Pin 2
sensors are built in on motoriono. Or you attached seperately?.
XicoMBD (author)  altaf hussain2 years ago
I attached the sonar separately.
how it cost motoruini?.
XicoMBD (author)  altaf hussain2 years ago
how much it will cost?
ameyanaik3 years ago
awesome man !!
would love to see live video too..
XicoMBD (author)  ameyanaik3 years ago
I hope I can upload one this week :D
Hi again! I would live to see this move! Video?
XicoMBD (author)  jweymarn2 years ago
The propellers I bought were too big, so I created a different boat. You can see the photos and videos here:
how well does it work? does it go fast? if so how fast?
jweymarn3 years ago
Good idea! Video?
XicoMBD (author)  jweymarn3 years ago
I'm waiting for new propellers to arrive.
When I got them, I'll shoot one video immediately.
arduinoboy3 years ago
Hi Xico! BittyBot from LMR! Hope you win! ;P
XicoMBD (author)  arduinoboy3 years ago
Thanks BittyBot!
heavyfire883 years ago