Recently, I picked up a Tamiya "Planetary Gear box Set" and took a little less than an hour to assemble: http://hiwaay.net/~bzwilson/prius/pri_pds.html It would make a nice core for some excellent science fair projects. It also solves the 'headache' problem that comes from trying to understand the Toyota TSD/HSD. Bob Wilson
http://www.hobbylinc.com/htm/tam/tam72001.htm - ~$20 w/shipping http://www.pololu.com/products/tamiya/0070/ - $18 free shipping on order over $25 if there's other stuff you need. http://cgi.ebay.com/New-Tamiya-Planetary-G...3QQcmdZViewItem $10 starts bidding w/ $6 shipping. BTW, cool find...thanks for sharing.