[Superseded] Quick removable Spool Holder for Prusa i3

[Superseded] I made a new version including a filament guide and more convenient to manipulate, please check here: http://www.thingiverse.com/thing:1688923


I designed this spool holder in order to be able to easily change filament spool.

In this design, you do not need to screw or unscrew anything, just take the threaded rod with the spool on it, make the spool slide out of the rod, put the new one and just put back the rod. The left nuts are fixed using Loctit, but double nuts will work