Glass bed corner

I have mounted my second Prusa I3... this one is for my use... the
last one was mounted to be used in my job as secondary school teacher. In this case I have no used the complete kit sold by BQ and I have bought pieces from different sources, I have printed other from Thingiverse and I have designed other. For the glass bed I have designed a set of pieces for the corners of the methacrylate base that block the glass bed without use the famous clips who hit with the extruder a lot of times. They permit use of leveling nuts