3D Printed Bridge

This is a design for a 3D printed bridge. The designed length is 6 inch and the weight is 22.1g. According to the test, it can hold up to 22.4kg with a load to weight ratio a little bit over one thousand. STL files for each unique individual member are included and there are also two printer-friendly STL files ("35" and "50"). All the members except KM and ML (see the design pdf with computation on it) have 35% infill, while KM and ML have 50% infill.