Toilet paper tubes Robots


  • Bristlebot Robotics Kit, available from our company The kit contains enough parts to build two junkbots, as well as two smaller robots, called bristlebots. To build one junkbot, you will need these parts from the kit:
    • AA batteries (2)
    • AA battery holder
    • Large motor
  • You will also need the following supplies. These are just suggestions; you do not need to use all of them, and you can pick other materials not listed here:
    • Recycled construction materials, like plastic bottles, cardboard tubes, etcetera
    • Other construction materials, like popsicle sticks and straws
    • Various adhesives and attachment mechanisms, like clear tape, duct tape, rubber bands, zip ties, glue (a hot glue gun is helpful, but adult supervision is recommended)
    • Decorative items, like googly eyes, pipe cleaners, construction paper, glitter, crayons and markers, etcetera
    • Corks (these are pressed on to the motor shafts to make the motors vibrate)
    • Scissors (older students can use hobby knives, adult supervision recommended)
    • Small Phillips-head screwdriver


  1. Make sure your battery holder’s switch is in the OFF position.
  2. Use a small Phillips-head screwdriver to remove the screw, then slide off the battery holder’s cover.
  3. Insert two AA batteries into the holder. The flat ends of the batteries should be against the metal springs.
  4. Slide the cover back on until it clicks into place. You do not need to replace the screw.
  5. Twist together the red and black wires from the motor and battery holder.
  6. Wrap the exposed metal parts of the wires in tape to help prevent short circuits.
  7. Firmly press a cork onto the motor’s shaft.
  8. Turn the battery holder’s switch to ON. The cork should spin, causing the motor to vibe. Then turn the switch off again.
  9. Build a “body” for your robot out of recycled and craft materials. There is no right or wrong way to do this step—what you build is up to you!
  10. Do not forget to decorate your robot!
  11. Attach the battery pack and motor to your robot’s body. Pay attention to these tips:
    1. Make sure you do not glue or tape the battery pack shut, or make it difficult to access. Eventually you will need to slide it open to replace the batteries.
    2. Make sure the cork can rotate completely without getting stuck against the robot’s body.
    3. Make sure the wires will not get tangled in the cork when the robot moves.

  12. Turn your battery pack on, put your robot on the floor, and watch it go! Your robot might not work perfectly on the first try, and it might not work at all. This is okay; use your problem solving skills to fix it. See the Troubleshooting section if your robot does not work.
  13. If you are doing this activity with a friend, try racing your robots against each other or making them “sumo wrestle” by pushing each other out of a ring.
  14. Troubleshooting

    My cork does not spin when I turn my battery pack on.

    • Make sure you inserted your AA batteries properly. The flat ends of the batteries should be against the metal springs in the battery holder, and the “+” signs on the batteries should line up with the “+ signs inside the battery holder.
    • Make sure you do not have a short circuit. This can occur if the red and black wires bump into each other and you did not securely wrap the exposed metal parts with tape. Short circuits will prevent the motor from spinning and quickly drain the battery.
    • Make sure the cork can spin freely and is not jammed against the robot’s body, held in place with glue, etc

    The cork flies off the motor shaft when it spins.

    • Press the cork further onto the motor shaft using a new hole.
    • Optionally, a small dab of hot glue placed in the hole can help hold the cork in place.

    My robot stopped working suddenly.

    • Remove the tape from your wires and make sure the metal parts are still twisted together. The motor’s vibrations can cause the wires to come apart if they are not twisted tightly enough.
    • If you have access to a soldering iron, you can ask an adult to help you solder the wires together. That will help keep them connected.

    The cork spins, but my robot does not move at all, or moves very slowly.

    Several things can prevent your robot from moving or make it slow:

    • There is too much friction between your robot and the ground. Try putting your robot on a smoother surface or using a different material for its “feet.”
    • Your robot is too heavy. Try removing some materials from your robot or using lighter materials.
    • Your motor is not firmly attached to the robot’s body. This means the vibrations will not transfer from the motor to the robot’s body. Try using more glue or tape to securely attach the motor to the robot, but make sure the cork can still spin.
    • Your robot’s body is not stiff enough (for example, cardboard pieces held loosely together by tape). This can cause all the vibrations from the motor to be absorbed by the robot’s body, instead of transferring to the ground and causing the robot to move. Make sure all the different parts of your robot’s body are tightly taped or glued together.

    My robot does not go straight.

    • This is very common—since your robot is powered by vibrations, it is actually very difficult to make one that goes perfectly straight. So, do not consider this a problem—consider it an engineering challenge!


  1. Make sure you turn the battery pack off to avoid draining the battery.
  2. For long-term storage, remove the batteries from the battery pack.