Spool holder (Prusa and Graber)

A simplistic design to hold the spool above the printer and align the filament with the extruder.

When I was designing/editing this part, I had three goals in mind:
1 - filament economy - has infill holes
2 - strength - supports 1kg of filament without problem (never tested with more than that)
3 - praticity - only uses 2x m3 screws and 2x m3 nuts
I believe these goals were accomplished.

I'm using it about a year now and never had any problem.
Also recommend to print the 608zz adapter