This is my design of the clip for glass bed installed on wanhao duplicator 6 or i3.
These fit on the corner of the bed (see pics) and it works for glass between 3 and 3.5 mm (thickness).
I have printed these in PLA and in PETG, both work, but PETG is much better obviously.
WD6_glass_bed_clip.stl | 91.2KB |