So Yosuke's filament guide is awesome, but his spool holder does not work with the stock Lack connectors (his are thinner wall). He also presumes you will use the Bear 2020 Spool Holder which, okay, but that means you're buying two different sizes of bearings and they're cheaper by the ten-lot.
This bolts to the bottom of whatever enclosure using whatever screws. It uses 2x 688 bearings, which, since you have six left over, works out.
This version is force-fit because of the little half-mm dingus I put in there. I put it together with channel-locks because I don't see myself changing it out ever. If you want something looser, hit me up and I'll dink with the SolidWorks file. Or, hey, do it yourself.
Bracket comes out better if you print it on the long flat side and support the end a little. Reel prints on-end. I went PETG, you do you.
The author remixed this model.