dampener plate for Prusa i3 MK2 (squash ball)

You all know that the geometry of Original Prusa i3 MK2 is quite tricky. When you have a flat and square frame, you would like to keep it flat ... a long time !
However if you move the printer you may wrap a little the XY frame and loose the XYZ calibration.
I have thus designed this reinforcement plate with two goals in mind :
- add some stiffness to the XY frame and keep it horizontal ... forever
- dampen the vibrations with my squash ball feets

Here is the result : it works really well