Create a DIY Electric Pencil Sharpener from an Old Bottle
With school kicking back into high gear for most people, don't be stuck with a dull pencil in class. If you're an engineer, you could certainly buy yourself a portable pencil sharpener, but imagine how impressed your professor would be if you made your own. Through the use of a small motor, a 9-volt battery and a soda bottle, you can create a rather functional little tool. Check out the build process in the video above.