Winning Design - Filament Spool Holder for 3DPN Filament Shelving System

This is one of three winning designs in Joel Telling's filament shelving system spool holder contest. A filament holder that just hangs from the front 1x2 will cause it to twist and warp over time and will not be very sturdy. My intent was to avoid this by designing a holder that hangs between the front and rear 1x2 thus not putting a strain on these wooden structures. Another design intent was to make the filament holder as non-obtrusive as possible allowing it to be positioned in as many lo