The 4 ring parts need to be glued together. New in version 8 (vs. version 5): Now easier to assemble.Flip the filament spool winding direction and guide the filament around the ring like shown on the photo. Note that the filament goes behind the Bowden tube. This stabilizes the ring. Additionally, I made a guide for the ring, which is simply clipped on the feeder. Its purpose is to prevent the ring from slipping off and falling. The reasoning behind this "reverse bend" trick is discussed in the Ultimaker forum: http://umforum.ultimaker.com/index.php?/topic/5454-ultimaker2-reduce-filament-friction-in-the-bowden...