SummaryBearing smooth, adjustable width top filament feeder, based on an elegant design by sadahisa. I included both a solid and an open version that uses less material. https://www.youtube.com/watch?v=wYxuVQTHQLEInstructionsI modified this very elegant spooler a bit to accommodate different spool sizes and added a bar in the center (3/16") so as to relieve the filament from grazing against the slot at the top of the printer. The bearings are supported by 8/32 screws drilled and tapped. I ganged both screen door rollers and skatewheel bearings for versatlility and bracketed with fender washers. The bushing for the skatewheel bearings is a plastic tube from a hobby shop that happened to fit nicely. Also included in the photos is a single bearing design that should be pretty universal. Enjoy!