Tell us about yourself!
Arduino controlled wind chimes
Building a 1:1 Scale Portal Gun with Lights
It is pretty small and inefficient but you could do it. I have not tried it though so I can not tell you how much power you could expect to produce.
Plastic would likely work just fine.
Probably, plastic is not likely to be as perfectly round so you will probably have more friction making your engine less efficient.
Logitech X-230 concrete speaker mod
Modification of the Lexmark E260 for Direct Laser Printing of Printed Circuit Boards - MCU Version
A Simple Introduction to Transistors and PWM (Pulse-Width Modulation)
Projector Bulb Conversion To LED
A Preamplifier for Smartphone Oscilloscopes
Blue Flaming Pinecones
Cheap, easy, low-waste platform bed plans
Simple Servo Tester
Toner transfer no-soak, high-quality, double sided PCBs at home
Stop using Ferric Chloride etchant! (A better etching solution.)
Running 3 monitors by installing second PCI Express card