clip glass prusa MK2

I love my prusa mk2 and I wanted to print on glass with it, so I checked out techtiptricks video on youtube about that: https://www.youtube.com/watch?v=VQNCvE2OLhA

The gcode to do this is available on prusamk2.com: http://www.prusamk2.com/printing-on-glass-with-youre-prusa-i3-mk2-ohhh-so-smooth/

Unfortunately all my clips to hold the glass didn't work verry well and were often been pulled away by the extruder, like in techtipricks video. So I created my own clips that can be integrated int