Wire Spool holder & role

I was looking for a good spool holder for my wires, as soon as i do not buy wire sets i have a lot of wires laying around without any arrangement, so i made this design to organize my work as much as possible.
I used one 8mm (the lenght could by any,you decide :) ) rod and 4 nuts to secure all there. You probably have them laying around your 3d printer.

Spool dimensions:
Length 40 mm
Diameter 40 mm
Hole 10.5 mm;