Use some pliers to pop open an old badge reel and pull out the spring. Slide the tab of the spring into the hole in the spring housing's wall. Wind the spring inside of the housing and case and secure it around the case's pins. Put a few dots of CA glue in the holes in the case's corners and slide the lid's pins into them.

It should be noted that this is not a very secure QR. I use them around the house mostly, not on anything critical lol. I tested with Prusa PC Blend and the key, pin, and loop were quite strong. Too strong to easily break with bare hands.

Printing Advice:

• Use a somewhat elastic material like PC or PETG for better strength and longevity
• 0.15mm layer height
• 100% infill

The “ALTOIDS” on the lid in the photo is not on the model uploaded here.