remix of Boots Industries filament spool holder

This is a modification of the Boots Industries (BI) filament spool holder design, published on Thingiverse. As with the original, it uses a single 608ZZ bearing, but uses a bit more 4mm hardware, in order to both clamp the bearing in place securely and to allow fine-tuning of the drag desired to govern spool rotation.
Various brands of filament have spools with different diameters of the hub hole. The BI design requires a different removable adapter piece for each different diameter, where this redesign can support multiple different diameters in a single fixed spinner. With similar slicing paramenters and PLA, the BI base and platform together weigh about 34g, and the redesigned base and multi-diameter spinner together also weigh about 34g. The BI design also needs one adapter per different spool hub hole diameter, at about 27g each. The BI base is 120mm in diameter; the redesigned base files are uploaded at 120mm diameter and 98mm diameter, and other sizes could be readily created by modifying a parameter and recompiling in openSCAD. The spinner design uploaded is for these reel hub hole diameters: 2", 1.5", 1.25", 0.75". Other combinations could be generated by modifying the program parameters in openSCAD and recompiling the spinner.