Rolling Filament Stand

Inspired by [TUSH - The Ultimate Spool Holder](https://www.thingiverse.com/thing:2047554).

This model includes feet for stability, consists of one piece instead of two for simplicity and durability, and makes installing the bearings easy with a push-through snap-fit from below.

Two of these are required for each filament spool. Each side requires two 608 bearings (that's four total, for those whose skills do not extend into the realm of mathematics).

Edit 2 Dec 2021
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Added a double holder that can be used for chaining filaments, if that's your thing.