Integrated Auto-Rewind Spool Holder

**Use V5.5 or newer, double-check version of your files!** (zip download has issues)

Filament load/unload issues? MMU2 taking too much space? Not with this Integrated Auto-Rewind spool holder! It keeps filament on the spool during unloading, up to, a few full revolutions.

This integrated design is the fifth iteration in the Auto-Rewind Spool Holder series, after the Original, Parametric, Universal and Sisyphus iterations. It returns to the roots of the series with the spring wound up inside the cylindrical space of the hub, as opposed to the side-spring designs. While the diameter is relatively small (45 mm-ish), almost the full width of the spool holder can be utilized allowing to stack many small springs and obtain sufficient rewinding revolutions at a good torque profile.

From V5.5 the arrows on both caps indicate the preferred direction of rotation (may be the wrong way round). The preferred direction is the one that causes all springs to wind up around the axle, which is