Universal Spool Holder

This Universal Spool Holder will work, set on a table, for any printer but is really designed to be hung on a Prusa i3 MK2 or MK3.

As all Original Prusa i3 owners know, the spool holder that comes with the printer is pretty rubbish. There are many alternatives available here on Thingiverse but none of them would handle all of my needs. This spool holder will:
- Support large (over 2Kg) spools
- Allow a heavy spool to roll freely
- Fit any size (width) spool
- Handle two (or more) spools for quick colour change mid print
- Hold loose "sample size" coils of filament

The left support has left-hand threads and the right support has a right-hand threads. This allows you to screw both ends together at once (obviously, one end of the rod has a left hand thread). Near the ends of the rods there are small flat sections so you can use a 6mm wrench to tighten the rods. As the rods are printed flat, the threads may be less than perfect. I've included a left-hand threaded nut that