Homemade Spinning Brushbot

What better way to get kids interested in science and technology than fun, hands-on projects that move on their own? This simple, homemade, spinning brushbot was inspired by the book How to Build Robots. This book recommends taking apart a battery-powered, electric toothbrush to get the parts for this project. While that sounds like fun, I have a lot of kids I plan to make this with, so I decided to just buy the little motors and toothbrushes in bulk to save money. I also added some googly eyes and changed the positioning slightly to make it look more like a cute little bug.

Like the other “robots” on this site, this little spinning brushbot is not REALLY a robot, since it doesn’t have any sensors or respond to its environment. I’m still planning to get there sooner or later, so sign up for my newsletter if you’re interested in staying up-to-date!

The reason why I’ve held off on making a robot of this type before was because I didn’t trust my littlest munchkins not to eat the cell batteries. Combined with my constant vigilance during the construction process, I now have a crew that I am confident will survive the robot-making party we’re planning to have in the near future. If you have little kiddos, know that this project does contain choking hazards and use your best judgement!

Here is a short clip of my little brushbot in action!

Recommended Age Range: Kindergarten, Elementary, Middle School
Time Required: ~30 minutes
Difficulty: Easy
Cost: Less than $5 in used supplies to make one (The more you make, the cheaper the cost as buying in bulk saves a lot!)

Materials:

• toothbrusth (here’s the 50 pack we used if you have a big group)
• Mini vibration motor (This link is not exactly the same, but similar to what I used. You could also get a motor from inside a battery-powered electric toothbrush)
• Mounting tape
• 3V cell battery (This is a link for the 20 pack we used.)
• Googly eyes (mine are approximately 1/2″ or 12 mm, but came in a mixed size bag)

Supplies:

• Scissors
• Wire strippers
• Cutting pliers (or anything to cut the head off the toothbrush)

Instructions:

1. 1. Use the cutting pliers to cut the head off the toothbrush.

1. 1. Use your fingers to spread out the bristles. For improved stability, place a book on top of the toothbrush head with the bristles spread for several minutes (or as long as you wish).

1. 1. Use the wire stripper to expose about 1/4″ of wire on each of the leads coming from the motor.

1. 1. Cut a piece of mounting tape slightly smaller than a googly eye.

1. 1. Use the sticky side to attach one of the wires from the motor to the front of the cell battery in the location you would like to stick the googly eye.

1. 1. Peel off the backing and stick a googly eye on.
   2. Apply another piece of mounting tape for the second eye (without putting a wire under this side).

1. 1. Peel off backing and apply second googly eye.

1. 1. Use mounting tape to apply motor to toothbrush. It’s fun to experiment with the placement of the motor. Too far in one direction will cause the bot to tip over from being too heavy on one side. Too far in the other direction will cause it to spin so fast it eventually flips over. I found placing the motor approximately as shown worked pretty well. Make sure not to tape down the spinning part of the motor.

1. 1. Use another piece of mounting tape to attach the second wire to the opposite side of the battery. Note that at this point the motor will start spinning.

1. 1. Place another piece of mounting tape onto the non-spinning end of the motor and the front of the toothbrush. Peel off the backing.

1. 1. Peel the backing off the tape on the battery and attach it to the tape on the motor.

1. Put it down and watch it spin! (See video above.)

ENJOY!
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