here is a simple wall mounted spool holder that you can screw to any wall, sticks out at 90°.
I also made some simple cuffs which you can insert a M5 nut behind and a thumbscrew to clamp and lock spool into any position on rod.
print spool tube with 30% fill, no supports
plastic reel guides with support for nut area only and at 40% fill as well
added a part Spool Feed which fits over the cuffs and keeps your filament aligned with the spool so it doesn't skip over sides.
Also added spaces, you can print these to insert between plastic reels and filament spools.
Also added a knurled knob for an M5 Screw with Hex head
If you print and like them please post your photos!