My Reprap Prusa I3 bed always make a noise and vibrating when across the Y axial, I make a little modification by adding one more bracket, usualy its using 3 bracket, 2 in Right and 1 in the left, the left one is not good enough and cause the vibrate, so I decide to add a new bracket, but its not good when one is aluminium and another is PLA Plastic, I build 2 bracket and release the aluminium one.After installation and test, my printer is now quiet, smooth, and work like a charm.