Note... after some consideration Ive decided to do a mk2 of this that will feature a retainer for the races and be 100% printed, ie no steel balls Horizontal filament holder for a delta printer, This was designed specifically for the RepRapPro Fisher but would be suitable for others, especially if they have a flat top suitable to put the filaments on. Essentially this is a thrust bearing design, and in fact can be used for a wide range of applications where something needs to rotate. Need a Lazy Susan for your dinner party?.... just put a plate on top of this and your golden. Want to rotate a heavy object? pop one of these under it and it will spin like very easily The completed assembly requires two races to be printed and uses 1/2" balls, the ball spacer is optional and just makes it possible to use less balls, if you end up using this for heavy loads then maybe remove the spacer and fill the race with as many balls as you can. Before a reel is placed on top you will also need a Spigot, most reels have an indented feature that can take a spigot, Ive included the two spigots for the reels I currently use, but its easy to make more with the most basic of CAD packages. Its also possible to stack your unused filaments on top of each other by making spigots that can key one reel to the other, however take care not to overload your printer top of make the stack so high it becomes unstable. This uses 1/2" balls but can easily be scaled for any size, you need two of the race parts. Early versions of this used more balls and worked fine, the spacer is a new mod, less balls means less rolling resistance, but also less load capacity. The spigots are spool specific the smaller on is suitable for a Sun Filament spool, the larger one is for a 1kg spool brand unknown.