mechanical direction control for my logging truck 
http://www.youtube.com/watch?v=NhE6kt-3Dlo

Lego mechanical direction control "how to" 
http://www.youtube.com/watch?v=FXUuH1CVJPU

Logging crane for lego 9397 
http://www.youtube.com/watch?v=g_nmdHkr2mQ