Ender-2 Spool Adapters

In time I designed these three spool holder accessories to upgrade my Ender-2:

- First a doughnut that goes on the original spool holder to prevent the spool from rubbing on the vertical C-Channel metal support.

- Then I designed the thinner spool holder (remixed from the one for my Printrbot Simple Metal found on Youmagine) to take some spools I have that have smaller hole than the stock Ender-2 spool support.

- Last, having upgraded my Tevo Tornado to dual spool bearing spool holder, I designed remixed the filament holder extension to hold a 16cm long 8mm diameter threaded rod and the following spool support: https://www.thingiverse.com/thing:2070272