Hand-Cranked Flashlight


•  LED Cube
•  Motor Cube
•  LEGO® 4x8 plate and wheel


Tenka Labs


Build your own flashlight according to the directions and then try it a different way. Circuit Cubes work like electricity actually works. You need to connect the Cubes properly to turn them on. But sometimes you have to know how not to make something work in order to make it work!


1  Gather the LED and Motor Cubs, the LEGO plate, and the wheel

2  Mount  the LED cube onto the LEGO plate, aligning the two plastic posts with the outer edge of the plate

3  Mount the Motor Cube onto the plate so that the metal posts on the Motor Cube will be next to the metal posts of the LED Cube

4  Place the wheel onto the shaft of the Motor Cube

5  Now turn the wheel to generate your own energy and power the LED Cube.

TIP: The LED will only turn on when you spin the wheel in a certain direction; it doesn’t work in both directions. This is because the LED is polarized and only allows the flow of energy one way. Experiment with the different directions to figure out which is the correct way to make your flashlight turn on.