first you will need the motor of a fan.( the crappy ones you get at the 99 cents store are perfect)second you will need a sheet of metal.( a soda can is good)a nine volt batterytoolsyou will need scisorsand you will need safety equipment. this is very sharp and can cut you!
Step 1: Makig the sheet
to make the metal sheet, take the soda can and cut it so it wil lay as a flat sheet. then cut it so it is about one inch by one inch. to get the hole through it just take scissors and poke a very very small hole.