E3D BigBox spool holder upgrade

This is an upgrade for the stock spool holder design to add a guided offset for the spool of the back of the BigBox case.

The stock design works good for normal spools although I had an issue with black spools leaving black scratches in my polar white case which looks not very nice.
The design definitely failed for me with 2.2kg productions spools from Colorfabb because the spool has a much bigger diameter so the spool can get in contact with the protruding screw heads.

To mount the space