Dagoma's simple and smart spool holder is great, but I have this packet of skateboard bearing bought for my initial spooler design, so I designed something to leverage dagoma's concept and a bearing. The result is a spooler that completely reduces all friction; when the extruder pulls, there's no holding back. In fact, it'll even wind back up if the print head moves in such a way as to push the filament back toward the spooler.
After an initial design to hold the bearing, I mimicked dagoma's shroud to spin on top, but this was hard work to customize each time for smaller widths as the design was done in Fusion 360 to help learn some of its features. In the end I decided on a stepped edge on which I hope most spools will happily rest. The video shows 4 examples.
Both the spike on which the bearing is mounted, and the hole into which the bearing is pushed are tapered in order to create a strong hold and minimize wobble. You'll probably need to push somewhat to get the bearing all the way in, so it'll probably be hard to retrieve. Then again, it's only a single bearing.
Both parts print with no support.