filament spool holder clip-on rail 2020 openbuild v-slot

spool holder that clips on a standard 2020 openbuild rail.
I built this for my sunhokey prusa 'i4', to have the spool on top of the printer. Will work on any standard 2020 rail, no bolts or nuts, just clip in place.
Must be vertical (or change it so the spool axis clips to the pillars. this is just kept in place by gravity, as is.)
i join the original freecad files, remix at will :)
Needs supports for the square pegs, will work well with low infill (5-10%)