Ultimachine 5 lbs filament spool core with 608 bearings
Ultimachine sells large, 5 lbs (2.3 kg) spools of filament. These spools are a bit large to put on a lazy susan or mount on the back of many 3D printers. Consequently, I designed this spool core to be part of a support system for these large spools. The core acts as a heavy duty spindle to support the spool and to present two press-fitted 608 skate bearings through which an 8mm diameter axle may pass to hold the spool. The spool rotates around the axle with ease owing to the bearings; this should put less strain on your extruder feed mechanism as it presents less static friction than other possible spindle systems.
The press-fitted 608 skate bearings may be locked in place using an M3 nut and bolt acting as a set screw.
A fully parametric OpenSCAD source file is also provided.