Original is at http://www.thingiverse.com/thing:6640
RP every .scad in this directory once. Aim for 0.3mm layers and 2.2 extrusion width (width over thickness), for 0.66mm stroke width, with 2 perimeters. Bot is tested at this setting.
Your printer should be able to do 5cm bridges.
All comments assume you are looking at the bot from the side of motors