Simple Prusa Mk3 filament spool holder sleeve and guide

One of the main complaints of the Prusa i3 MK3 printer is how filament rocks forward and backward on the stock filament holder which mounts on top of the printer frame. Many other filament holders have been created and made available on Thingiverse and I've tried several including the ones with skate rollers. One of the things I didn't like with those filament spool holders is how the spool sometimes over-spin and the filament comes loose in the spool. I truly believe a bit of friction is needed to keep the spool from over-spinning and I was wanting to re-use the stock spool holder. I created an extremely simple sleeve to go over the spool holder to allow the filament spool to spin more smoothly and reduce the forward and backward rocking. This is quite literally the easiest and simplest filament spool mod for the prusa mk3 to drastically improve the stock spool holder. I've also included my own filament guide as well which works amazingly well with the modified spool holder.