Unobtrusive frame brace

Brace to fix the inherent wobble of the Prusa Mendel.

I tried other frame braces but they all cut down on the maximum printing height so I designed this brace to keep the central printing area clear.

This can only be used if you have about 2 cm or more threaded rod left protruding from the upper x axis frame.

You also need to print four of these http://www.thingiverse.com/thing:34134