External Spool Holder and Guide

2024-01-18: Increased the tolerances on the holes for the bearings by 0.2mm. Use a rubber mallet to fit all pieces together.2024-01-13: By request on the BL Discord, I have added a low-height filament guide that pulls from the bottom instead the top. This external spool holder puts your external spool directly to the left of your printer. I didn't like having it behind the printer, making it hard to access, and I don't like having things on top of my printer because of the vibrations. Th