About this 3D model

http://youtu.be/5LTZZl919KY The rollers are made of 32mm PVC pipe. The shaft is a threaded rod. Engine mount is 3D printed. Bearings holder and coupling between the engine and the axles of the rollers are also 3D printed. The band is made ​​of paper. The frame is made of 16 mm aluminum profiles. Motor find on eBay: DC12V 25mm 100RPM Mini Gear Box Motor for Electric Car