I created this simple spinning hook to display my partner's blind box collection underneath a ¾ inch shelf in our office. Since the key rings tend to be at different angles on each figure, the rotation of the hook helps keep them adjustable to hang straight. 
 

Additional parts needed:

• M3 x 10mm screw
   

Prusa MK3+ print settings:

• 0.2mm layer height
• 0.6mm nozzle
• 5-15% infill (consider 100% if you're hanging something heavier)
• Polymaker Polyterra PLA Matte Black Filament
   

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