Make:

Tools:
Safety glasses
Wire strippers
Screwdriver
Pliers
Utility knife
Multimeter
Soldering iron
Hot melt glue gun

Time frame:
The vibrobots can be made in 5 minutes or less, but give an hour to make sure you get at the important ideas of how to fasten round objects to flat surfaces and electric circuits.

Mastery objective:
Students and participants will know how an electric circuit works and how to attach materials together so that they can construct a vehicle that moves by operating a simple electric motor circuit.

Process:
Gather your materials and don your safety glasses.
Prep the motors
If your motors have wires on them, strip the end of the wires.
If the motors do not have wires on them, then solder wires to the motors. When soldering to motors, you need to be very careful to move quickly with the heat. Use only as much heat as will melt the solder onto the wire and the tab. You do have to get the tab hot. If the tab is not hot, the solder will not hold properly.
The wires should be at least a few inches long, and the end away from the motor should be stripped of insulation.

Weight the motor
To add a weight to the shaft of the motor, all you need is a small piece of hot melt glue stick. An inch or so should work fine, but experiment with more or less. With less material, it should spin faster with less of a wobble. With more material, it should spin slower with more of a wobble.
Stick the shaft of the motor into the glue stick at one end. When you do this, press from the back, usually plastic end of the motor. If you don't hold the end of the motor, sometimes it will pop off, possibly ruining the motor, but also showing you what the inner workings of the motor look like.
You can use other materials to weight the motor, like plastic and wood. Really, anything that you can get to grip on the motor shaft will work in some way.

Build a body
For the body, you can use anything that is relatively light. A mint tin can work, as you may be able to tuck the battery pack inside, and secure legs below.
Another feature of the mint tin is that you can put screws, nuts and bolts and other jangly stuff inside. This will make noise as your vibrobot bounces around the table.
If you want real simple, take a piece of plastic from the CD drive,

Attach your motor
The easiest way to attach the motor is to tape the motor to the deck.
You could get a more secure arrangement by using zip ties to hold it down.
A more secure arrangement would be to fashion a pillow block and bolt the motor onto the deck. You can make a pillow block by drilling a hole in a scrap of wood and then cutting it with a saw to hold the motor. You can also use the bottom half of the pillow block and zip tying the motor to the block and the deck.
If you are going to have the motor shaft parallel with the ground, you will need clearance for the weight to spin.

Right or left?
To determine which direction you want the motor to spin, the easiest way is to connect the wires from the battery pack to the wires from the motor. The motor will spin, clockwise or anticlockwise. If you switch the wires, the motor will spin in the reverse direction. You can check the circuit with a multimeter on DC voltage. If you get a positive reading in one direction, you should get a negative reading in the other direction.

Enjoy your creation
Vibrobots are not very smart beasts, but you should be able to run them on a table or floor. Watch that they don't fall over the edge, or build them for the durability that will help them survive the fall. Try it out, build one, and then build another to meet the shortcomings of the first.

Extensions:
Adding lights can sparkle up your vibrobot. LEDs are cheap and plentiful.
Using a motor reversing switch in your circuit will help aid navigation.
Remote controls aren't too hard to make, a length of CAT5 networking cable with a switch or two mounted on a board or mint tin at the top can make it start, stop, reverse direction and more.
A power switch on the body will help you turn the vehicle on and off easily.

More:

• Electronic Test Equipment from MAKE, Volume 10
• Multimeter Tutorial - Make: Video Podcast
• Multimeter Tutorial - Make: PDF Podcast
• Free classroom electricity posters
• How-To: CD drive scavenging for parts
• How-To: Free DIY battery holders
• How-To: Quick, cheap soldering stand