Anycubic i3 Mega narrow and frictionless Spool Holder Mod

I put my Anycubic i3 Mega in an IKEA housing ("STUVA" cabinet with "SINDVIK" glass door).

The cabinet is relatively large, but with the printer in it, the remaining space for the spool and spool holder is limited.

The original i3 Mega spool holder is not bad, as you can remove the spool upwards together with the axis on which it is mounted.

However, the spool holder is too wide for this compartment and so I created a modification (2 new ribs) for it too make it more narrow: aprox. 90mm