I've been using the excellent 'Universal Stand Alone Filament Spool Holder' (http://www.thingiverse.com/thing:508896) for some time with all my printers, and wanted to keep the versatility with my new Mini Kossel from Think3dPrint3d, so I remixed the universal spool holder to fit straight onto the supplied one. This allows me to easily use some of the more awkward sized reels (like Taulman 1lb reels for example), without any issues. The modified spool holder friction fits onto the existing spool mount.Update: Please use the 'adaptor3a - NEW VERSION August 2015' version as it's much stronger.