- OpenSCAD (2015.03 works, earlier versions might too but are untested.) - A steel nut and bolt for testing (Optional). :) - Optimized for Ulitmaker 2 and Cura (2015.02.1), but should also work for other printers and slicers. - Printed on Cura's Normal quick profile. (0.1mm layers, 0.8mm shells, 0.6mm top/bottom, 20% infill, <50mm/s effectively.)