The motor can be any small 10-20 watt, 120-volt AC motor that runs at 1,500-3,000 rpm. Old record players or small fans are a good source for these. If you can’t find anything lying around or at a thrift store, purchase a new small desk fan for around $10.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.