This integrated design is the fifth iteration in the Auto-Rewind Spool Holder series, after the original, parametric, universal and Sisyphus iterations.
This design returns to the original 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.
The default implementation does not include a dedicated clutch. The contact surface between rewinder and spool is used as slipping surface. The magnitude of the friction is determined by the combination of materials and its structure (roughness), and the weight of the spool itself.
Several parameters are available to specify the dimensions of the Integrated Auto-Rewind Spool Holder.
Axle, stand and clips are not included. You can use those of any of the other spring-based spool holders such as the Parametric or Universal Auto-Rewind Spool Holder.
v5.1 Narrow: max spool width 55 mm, hub width 60 mm
v5.1 Wide: max spool width 90 mm, hub width 95 mm
Earlier versions are available on Thingiverse.