Portable standalone spool holder.

thingiverse

A custom-made spool holder suitable for any standard 8mm shaft can be fabricated easily, and features an integrated slot for hassle-free attachment to Prusa i3 MDF frames or similar devices. For added functionality, I've included the option to attach a convenient 52mm spool shaft to this holder. It is accessible on Thingiverse at http://www.thingiverse.com/thing:430531 To utilize these components: Print all of the required parts first. Then simply snap them into place. Opting for a 25% fill density when printing should be sufficient, although feel free to experiment with higher densities if you desire stronger prints.