Summary

Did not find big rolls (spools) for my filament extruder.
So decide to design one.
Without center old 2.5 Kg of 3mm filament.
With center joint should hold 5 kg.
Include support for spool.
Add files to have rolls winded using simple Nema 17 motors.
Work fine on my extruder.
You need big printer for this, maybe you should build one !