How to build a BrushBot

BrushBots are super simple mini robots that only need a few bits of inexpensive kit to create. All the materials can be reused in other robotics projects too. They are easy to build and can be customised in many different ways!

These mini robots can be made as a class science project, a simple STEM challenge or just for fun!

Materials needed to make a BrushBot

AA battery and holder

1.5-3 Volt DC motor

Motor holder

Small brush

Hot glue gun or double-sided tape

Cork

Labelled diagram of a BrushBot for a STEM project

How to build a basic BrushBot

First, plan how you are going to create the circuit. The motor and motor holder must be on one end of the brush, and the cork needs space to spin freely.

Use either glue ( we used a hot glue gun ) or strong double-sided tape to hold the motor holder in place.

Put the motor inside and attach the cork.

Fix the battery holder and battery on the brush making sure the wires can reach the motor.

Attach the wires from the battery holder to the motor and check it spins.

Place the mini robot on a floor with a smooth surface.

The BrushBot should move wildly around on its own!

BrushBot made with a small children's hairbrush.

We added a switch to the bigger brush, but this wasn't necessary, and we added a bit of weight to the robot, which slowed it down.

BrushBot Troubleshooting

For the motor to spin, the circuit must be complete. If it's not turning, check the wires are connected to the motor correctly. Electricity needs a closed circuit to flow.

If the cork is spinning, but the BrushBot isn't moving, try changing the position of the cork so it's slightly off-centre. This will make the brush wobble more and move more quickly and dramatically!