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How to Make a Brush or Bristle Bot like a Mini Mad Scientist

Take your first step in the world of robotics with a brush bot you make yourself with just a toothbrush and a tiny motor.

green plastic turtle on a brush bot made from a toothbrush

~This post also contains affiliate links (including links to Amazon) which may reward me in the event of a sale.~

What is a Brush Bot?

Brush bots are very simple robots made from a vibrating motor and a small brush that acts as legs.

They’re also known as “bristle” bots since they bounce along on the bristles of the brush you’re using.

Brush Bots are similar to Hexbugs, a fun little “robot” you’ll find in the toy aisle. They can’t be programed or steered, you just turn them on and let them go! They’ll change direction as they skitter around and bump into things.

You can make a brush bot out of nearly any brush–if your motor is large enough!

LEGO minifig on a blue toothbrush brush bot

The bots we’ll make today use a toothbrush and a tiny motor used in pagers. (Do they still make pagers?)

You can find tiny vibrating motors at your local MicroCenter or online at Amazon. Amazon can get you a dozen motors for cheap, as long as you don’t mind planning ahead.

Buy it Now at Amazon: Micro Pager Motors for your DIY Brush Bot

If you’re one of my local readers, the St. Louis MicroCenter is at the Brentwood Promenade, near Target & Trader Joe’s.

Tape the wire to the brush

Make a Brush Bot

Active Time: 15 minutes
Total Time: 15 minutes

A brush bot is a very simple "robot" made from a tooth brushes and moves by vibration.

Materials

  • Small motor with two wires
  • Button cell battery
  • Toothbrush
  • Double stick foam tape or Sticky Tack

Tools

  • Pliers/wire cutter
  • Wire cutter, wire stripper (if needed)

Instructions

  1. Cut the handle off a new toothbrush, using the wire snips. Younger kids should let an adult to this.cutting the handle of a tooth brush off with snips
  2. If the wires to your motor are covered, use wire strippers to expose them.
  3. Place a piece of double stick foam/sticky tack on the back of the brush.
  4. Place ONE wire from the motor on top of the sticky foam/sticky tack and place a coin battery on top of that.Side view of a brush bot made with a tooth brush
  5. Use another piece of foam/tack to stick the OTHER wire to the top of the battery. This will also turn the motor on, so feel free to remove the wire after testing.
  6. Decorate your brush bot!

Notes

Unfortunately, there's no on/off switch with a home made brush bot. To turn it off, you'll have to pry the tape off too.

Sticky Tack is used to mount posters on the wall, you'll find it where tape is located.

Toothbrushes for Small Brush Bots

Toothbrushes make great small bots, but for goodness sake use a clean one. We’ve tried both flat bristle brushes and angled ones and they both work great!

How Do You make a Brush Bot Go Straight?

Getting a brush bot to go in a straight line is pretty difficult! If your bot keeps falling over or spinning in circles, you can SHAPE the bristles to guide it in the right direction.

The fastest way to shape the bristles is with heat and pressure. Warm the bristles with a heat gun for just a few seconds, then use your fingers to bend the bristles forward to go straight and smash them outward for more stability.

If you don’t have a heat gun, you can try warming the brush with a hair dryer. You just need the bristles to get a tiny bit soft, not totally melty.

Either way, hold the brush with a pair of tongs so you don’t burn your fingers with the heat gun or dryer.

toothbrush being turned into a bristle bot

What kind of Battery Powers a Brush Bot?

This bot is powered with a light weight “coin” battery. You’ll want one that is 1-3 volts, which is pretty average. They can get pricey, so I recommend grabbing some at the Dollar Store or from Amazon which has decent prices.

Assemble your Brush Bot with double stick foam tape or poster sticky tack. You don’t want anything permanent, like glue, because you’ll be taking the bot apart a lot.

Experiment with Your Bots

Half the fun of building a Brush Bot is playing around with the design. You’ll find the bot behaves differently depending on WHERE you place the motor and if you let the motor hang free or tie it to the brush.

pink brush bot with motor tied to handle using string

Decorate your Bot

A basic brush bot can be made in minutes — but you’ll have way more fun with them if you add decorations or small toys to act as drivers.

toy turtle on a brush bot with flames

Balance is key! You’ll need to play around with HOW you decorate your bot so you don’t tip it over.

Make a Track for your Bot

Like a Hexbug, these bots will move around in random directions…right off the table and under the couch! To avoid losing your wandering bots, put them in a box or create a track for them to give them direction. We’ve made simple tracks by lining up rulers or taping down straws.

You can also use Hot Wheels track, especially the old school flat tracks.

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