About this 3D model

This is a simple 3D printed chassis for an Arduino controlled robot that is part of the Learning in a Makerspace chapter of my new book "[The Makerspace Workbench](http://shop.oreilly.com/product/0636920028147.do)" from Maker Media! Simply print out the body and wheels, press in a common marble, attach a Tamiya 70168 gearbox, add a 9V battery and use an Arduino with motor shield for control. Enjoy!