The stock spool arm on the i3 is not long enough to hold a lot of spools, so this replacement should fix that. Alternatively can be customised if you want it a different size from my version.
Printer is also re-badged as Aldi Cocoon Create, Maker Select, and Malyan M150 i3 3D
Update (2016-07-04): Added STL for NoSupport version. Can be printed without any support material.
Update (2016-07-11): Modified SCAD file to allow generation of NoSupport version
Update (2017-06-06): Applied fix to SCAD provided by cmh (thanks)
Print it with the thread at the top, so the supports don't mess it up. Best in ABS as PLA will break too easily.