Prusa i3 Z-Axis Reinforcement

The original Prusa i3 frame suffers of one important problem: bed and frame are not really stiff connected, which causes displacement of layers and declines printing precision.
To improve the stability, here comes a very low cost solution:
A connection of the main frame (z-axis) with the base (y-axis). This easy connection uses only some parts: 2 clamps, 2 connectors for the rods and 3 additional threaded rods (one in exchange to the original one, two additional ones).
BOM:
2 threaded rods