Explanation of the Prusa's thick sheet is here: http://reprap.org/wiki/Thick_SheetThis design has a few improvements:The design could be improved by adding holes to mount something for opto endstops and slots for LM8UU holder zip ties.Update: I adjusted position and size of the holes for the belt clamp (so the belt can be shorter), heated build plate (was a tight fit in original), and LM8UU holes (so no print area is lost).Update 03/14: Corrected position of the belt clamp holes due to NikkeiRonin's suggestion. Added version for 3 lm8uu bushings like NikkeiRonin's thing. Use the following holders for your LM8UU: https://github.com/prusajr/PrusaMendel/blob/master/metric-prusa/y-bushing.stl