I could not find a gear/motor only kit for the Makerbot Botmobile (http://www.thingiverse.com/thing:13827) so I took the original drawing and extracted the 2 gears necessary to complete the drive train. All credits for the model go to the Makerbot crew who originally designed the car.Both gears need to be printed with external supports. I used the following settings: Infill 100% Layer Height 0.2mm Number of shells 1 Feedrate 80 mm/s Travel Feedrate 120 mm/s As these have 100% infill, I increasing the filament diameter in Print-O-Matic by +0.03mm for leaner print. I have not yet assembled the car but at a first glance the gears look as they will fit. Stay tuned for more updates............. :-)