Sturdier printed Z axis for prusa i3

This is a printed frame for the prusa i3

The design seeks to improve upon the rigidity of earlier designs by kknapp while still taking less time to print than designs by chocjulio66 et al.. The frame can be assembled incrementally - only the corner braces are absolutely necessary, the rest can be printed out and tacked on to provide additional rigidity.

The frame is built around a skeleton of six M8 threaded rods. On their own, the threaded rods are able to be bent, but when encased in plastic they form a sturdier composite material. This composite helps to increase the stability of the frame, thereby reducing x axis backlash.