Rolling spool holder for extrusion frames

Tried multiple spool holders, they all had some issue or another for my use case, so instead of looking again screw it, just made one.

The stand arm may be a bit overkill as bulk goes, but *I wanted to be sure* it stays there. And that it does! It's also compatible with some stock spool holders, so if you just want the stand because yours broke, it'll probably do!

**Instructions:**
All parts are in their recommended print orientation. The Holder and Roller parts need slicer supports, and they have some in-model supports meant to be clipped off. It's the thin bits at the bottom, can't miss them. Also be sure to add a brim to the Roller part, *just in case*. Tall prints be tricky.

Extra parts needed:
- 2x 608zz roller bearings.
- 3x M4 screws, 12mm in length.
- 3x M4 T-nuts.