Based on srepmub's OpenSCAD train track library, with a few additions. I can now make pretty much any track layout I can imagine! This is pretty much why I bought a 3D printer. :-) Changes: 1) Improved SCAD file readability (renamed methods & variables) 2) Added some new tracks (triple track, double curve) 3) Added smaller radius turns (curved and straight track small) 4) Works with connector thing http://www.thingiverse.com/thing:15165 Tested in PLA or ABS using 10% infill. The of the tracks are too large to fit the build platform of my Makerbot replicator. I have not yet built those pieces. I haven't tried the tunnel or the bridge track yet. Use http://www.thingiverse.com/thing:15165 for the connectors. Use http://www.thingiverse.com/thing:34194 for supports.