Spool Holder for MendelMax2 or any 20mm Extrustion

Simple design that allows for 4"-8"+ spool to be mounted to the top of a MendleMax2 or any other 20mm based extrusion. Uses standard 608ZZ bearings (skate bearings) and 1/4"-20 flat or oval heads screws and washers. Mounts will work with 5mm screws and T nuts from the top OR through-bolt to clamp from the bottom (in case you can't get T nuts in). Design features crash guards (for 8" spools) to keep a filament tangle from pulling the spool down on to the print bed or extruder. Spool rolls silky s