Tronxy/Prusa top feed spool holder, Real easy and works.

this simply slides onto the top frame of your prusa. any with the 7mm perspex frame.
and the spool sits on top.

Simple and easy.

print both the center rod and holder upright, with support and brim if you need.
i used 1mm walls and 70% fill for strength.

holds full 1kg spools no problems.
use with and 22mm spool centers.

ive included the one i use as they suit most spools.
sorry cant remember who i DL this from. its somewhere on here. cheers bud