Prusa i3 frame reinforcement

The frame of my Prusa i3 Hephestos was a little shaky, so I wanted to find a way to reinforce it while changing as few parts as possible.
With only four printed parts, two 8mmx350mm steel or aluminum rods and some glue you can considerably improve your printing quality.

instructions:
1. Print the files y-corner-left, y-corner-right, and two times holder-top
The quality doesn't really matter
2. Saw an 8mm rod into two 350mm pieces
3. Replace the y-corner parts of your printer with the