Toy Train for Legos

This is a derivative of my original train http://www.thingiverse.com/thing:11101 This version has wheels that work on the standard wood tracks that are a fairly common kids toy. There is also a 3D printer version of these available here: http://www.thingiverse.com/thing:8805

This version also accepts Legos and Mega Blocks. You can just snap them onto the top and build whatever you want.