Build Your Own Brushbot!


What is a BrushBot?

A BrushBot (sometimes called a “BristleBot”) is a very simple type of “robot” or vehicle that moves as a result of vibration from a small vibrating motor.

Many different BrushBot designs can be found on the Web. Some people have made remote-controlled BrushBots from scrub brushes and large motors. The folks at Evil Mad Scientist Laboratories may have created the modern BrushBot, or “BristleBot” design:
http://www.evilmadscientist.com/2007/bristlebot-a-tiny-directional-vibrobot/
A commercial BrushBot, called the “HexBug Nano”, is available from Radio Shack, other retailers, and online from various suppliers, for about $6-8. But much of the fun of BrushBots is in making them and modifying them. So let’s get started!

BrushBot Kit Parts List

1 Toothbrush Head
1 Vibrating Motor
1 Button Cell Battery, 1.5 volts
1 Clothespin
2 Toothpicks
2 Tape squares

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Tools (not included in kit):
Hot glue gun with hot glue
Fingernail clippers

Safety

You will use hot glue to assemble your brushbot. The hot glue and the tip of the glue gun can burn you if you touch it!
Allow the hot glue to cool before moving or testing your BrushBot.
The motor wires are very thin. They will break if you bend them too many times or pull on them too hard.
Please be careful!

Note

BrushBots are intended for use on smooth floors. They do not work well on carpeting or rough surfaces.

Build a Basic Brushbot

  • “Set the bristles” at an angle if you want your brushbot to travel forward. You can set the bristles by placing the brush under a book or other heavy object overnight. Make sure that the bristles are pointed in one direction. If you just want your BrushBot to spin around and do other random movements, you can skip this step.

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FRONT BACK
Note that bristles are bent back in this direction --->

  • Glue the motor to the front of the brush with a very small amount of hot glue. Apply the hot glue to the brush, not the motor.

NOTE: the ends of the bristles will point toward the back of the Brushbot. Make sure that you do not get any glue on or under the rotating part of the motor. This is the part that makes the motor vibrate, and it must be free to rotate.

  • Tape one motor wire to the “negative” (-) side of the battery. This is the side of the battery that has a protrusion. Make sure that it is taped down very well.
  • Using a tiny dab of hot glue, glue the “wired” side of the battery to the top of the brush.
  • Tape the other motor wire to the top (+ side) of the battery. The motor will start running.

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  • Test your BrushBot!
  • Disconnect the taped motor wire from the BrushBot when you are not using it to save the battery.


Modify Your BrushBot!


Add Stabilizers To Your BrushBot

Your BrushBot may tend to fall over. If that happens, you may want to add “outriggers,” or stabilizers, to prevent the BrushBot from falling over.
1) Cut each toothpick in half with nail clippers. Don't worry: this will not damage the nail clippers.
2) Glue the outriggers to the brush with just a tiny dab of hot glue, like the photo. Two outriggers support the sides, and one “tail” in the rear helps it travel straight.
3) Experiment with outrigger location. Try 4 outriggers as well.
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BrushBot “Mutations”

This BrushBot is a simple design, but you can modify your BrushBot too!
Add a clothespin: With a clothespin, you can easily connect and disconnect the wire to stop the motor without the use of tape.
Hot glue the brush to the bottom of the clothespin, and glue the motor to the top of the clothespin. The battery is then clamped between the jaws of the clothespin, holding the wires in place.
When you are done, the clothespin can also be decorated with googly eyes, paint or other decorations.
More details and photos coming on this modification.

Add another brush: A second brush can provide more stability, but may make your BrushBot run slower due to the additional weight.

Add a second motor: this modification will definitely add speed and performance to your BrushBot. You will probably want to add a second battery to power the additional motor.

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These are only a few of many possible variations

Experiment

Try changing the placement of the vibrating motor and battery, and test other positions for the outrigger toothpicks.
Can you make your BrushBot go faster?

Can you make it go straight, or in a circle?

Does the direction that the motor is facing affect the performance of the BrushBot?

How Does It Work?
The motor has an eccentric (offset) weight. As the motor spins, this weight causes the entire motor to vibrate, along with anything that is attached to the motor. The bristles of the brush reduce the contact with the ground for lower drag, and the springy-ness of the bristles helps the BrushBot to hop very slightly. If the bristles are set per the instructions, the bent bristles tend to push the BrushBot in one direction, instead of hopping around aimlessly.

Want More?

Contact Lycoming Robotics if you would like to purchase another BrushBot kit, extra motors, or other parts. If you are part of a Boy Scout Troop or other group that would like to build BrushBots and would like to purchase multiple BrushBot Kits, we can provide them at a quantity discount.


Copyright 2012 Lycoming Robotics