Universal Filament Spool Hub

Universal Filament Spool Hub (Uholder1.stl and Uholder2.stl ) is designed to reduce friction of the spool rotation. Excessive friction can lower the quality of the print. The hub can be kept with a spool during the storage. No need to remove the hub after and put it back before the print. Keep the hub on a spool all the time.

There were following design priorities:

- minimal friction;
- accommodate variety of spool widths and hole diameters;
- hub shouldn't extend the width of the spool too much (to fit more spools into container);
- easy, fast, secure lock/unlock on the spool (breech-lock is used);
- can be used on a printer or within a container;
- easy to build, minimal number of parts;
- minimum amount of plastic;
- no support is required (disable it);

Using bearings was deemed unnecessary as the friction of PLA and 6mm metal rod is very low.

Rod holders (AxelHolder.stl) for Original Prusa printers and containers (BarHolder1.stl and BarHolder2.stl) are included.