Duplo to Brio converter brick

This is a 3D printed piece that works as an interconnect between Duplo bricks from Lego and Brio wooden train tracks.

I was inspired by http://www.thingiverse.com/thing:4041, but after trying out a print, I found it too difficult for the 3 year old to put the tracks on, and I decided to make my own, slightly simpler design.

It's designed in OpenSCAD and I have uploaded the .scad file along with the .stl file, so that you can easily modify as needed