I made this motor about 8 years ago when Jane was a baby (she's the one who keeps crying "Dad-dee! Dad-dee!" near the end of the video). I learned about it from this Howtoons cartoon, which appears in every issue of MAKE.
It's very easy to make the motor. You need:
-- 12" of hook-up wire
-- One 1.5 battery
-- One neodymium magnet (the one I used is ½" square. You can buy a set of four for $10.29 on Amazon)
-- Nail polish
-- Two safety pins (you could use the hook up-wire or paperclips if you bend loops into them)
-- Scotch tape (to attach safety pins to battery)
-- Pad of Post-It Notes
-- Wire cutters / wire strippers
Here's how to make it:
1. Make a coil out of the hook-up wire as shown and strip off about ½" of insulation from the ends. (Tip: Wrap the wire around the battery to make the coil.)
2. Coat the top half of the exposed part of the wires with nail polish. Look at the illustration here to see what I mean.
3. Stick the safety pins to the battery terminal with the tape. (Tip: Howtoons uses a rubber band to accomplish the same thing).
4. Insert the wire coil into the loops of the safety pins.
5. Use enough Post-It Notes to get the magnet as close as possible to the coil.
You might need to flick the coil to get it started.
The best part about making this video and uploading it to YouTube is reading the comments from the Big-business-is-surpressing-free-energy crowd: "Haha my dad works for ExxonMobile. Trust me. They suppress this stuff." and "Unlimited energy sources are out there!But the powerfull Oil business won't alow common ppl to know this"
If you like this project, you should get a copy of Howtoons, which is loaded with fun things for kids and parents to make.
Read more in Family at Boing Boing
Mark Frauenfelder is the founder of Boing Boing and the editor-in-chief of MAKE and Cool Tools. Twitter: @frauenfelder. His new book is Maker Dad: Lunch Box Guitars, Antigravity Jars, and 22 Other Incredibly Cool Father-Daughter DIY Projects