My bristle bot is a simple robot made of a cell battery, a toothbrush and a small vibrating motor.
Step 1: Collecting together the stuff you need
1 x cell battery (I used 3 v)
1 x vibrating motor (I used a 11.6 x 4.6 x 4.8mm vibration motor from Robot Gear)
1 x toothbrush (choose one without rubber on the back. My experience is the rubber makes it very hard for the tape to stick. I used one with slightly angled bristles on the belief this would make it travel more easily)
1 x piece of double sided foam tape to the size of the back of the toothbrush head
Some sticky tape (optional for sticking wires to the battery
Step 2: Make Bot body
Snap the head of the toothbrush off the toothbrush and stick the double sided tape to the back
On further testing I have found using blutack both more effective than double sided tape. It is better at sticking and it is more flexible as I can very easily move the components around to find the right alignment to get the bot travelling in a straighter line.
Step 3: Adding the engine room
Strip off a small amount of insulation from both motor wires to increase the points of contact.
Place the motor to one end of the toothbrush head
Stick the blue wire to the middle of the remaining space by placing it on the double sided tape
Step 4: The giver of energy
Place the battery on top of the double sided tape. This will create contact with the blue wire. The closer to centre you place the battery and the motor, the straighter your brush bot will travel.
Step 5: I feel the need, the need for speed
Time to get your bristle bot running. Get your red wire to make contact with the battery and away you go. I stuck the red wire on with sticky tape to hold it in place.
And as you can see I had some fun making mine into a fly.