Quick release spool holder

thingiverse

Spring-loaded filament holder: push the spool to compress the spring, remove the slotted flange by pulling it off, then slide the spool right out. This saves time and effort compared to unscrewing nuts to take off the spool. Note that you'll need a nut on either side of the static bearing inside the slotted flange, as well as a lock nut on the spring side - a picture shows two nuts locked together since nyloc nuts weren't available.