This is super easy to make and woks supprisingly well!
its pretty cool
Step 1: Pats
Here's The things you need:
1.Lego Mindstorms motor
2.a few lego parts
3.short lego cable
Step 2: Attatch the cable
Put one end on the contacts, and the other end on the bottom of the motor.
Step 3: Attatch the crank
stat with putting a 90 degree angle "attacher thingy" (I know,very technical lingo) on the end coming out of the motor. then attatch a "stick" the another "attatcher, then another "stick"
Step 4: LED
Attatch the LED by pulling the leads appart, then wedging it in the bottom of the block on the side free side of the wire. each lead should be toutching the contacts diagonal from eachother
Step 5: Done!
thee you go just crank itand it should work, if not, crank it the other way